Vitamin D articles in free Scholarly Encyclopedia (more than 100)

https://encyclopedia.pub/ many are adapted from MDPI publications, subsidized by MDPI

Also includes: Mg, Vit K, Omega-3, etc
Many of the Vitamin D entries as of Jan 2024

Also includes: Mg, Vit K, Omega-3, etc

Many of the Vitamin D entries as of Jan 2024

Vitamin D—Practical Considerations and Clinical Guidance

Empirical evidence establishes the connection between exposure and clinical outcomes. Clinical studies show that chronic diseases and infections can be prevented by proactively correcting vitamin D deficiency in individuals who are vitamin D deficient, and in the community. In RCTs, with proper daily or once-a-week vitamin D supplementation in the intervention group, the serum 25(OH)D concentration must be meaningfully increased to the above pre-planned level to ensure the validity of the clinical study. Clinical outcomes correlate well with the serum 25(OH)D concentrations but not necessarily with the administered doses. It is a common error by researchers and healthcare workers to assume that the amount taken automatically produces the stipulated serum levels.
38601 Nov 2023
Sections include:

Vitamin D is a Threshold Nutrient
Adverse Effects of Vitamin D are Rare
A Small number of People Require High Doses to Alleviate Intractable Symptoms
Diagnosing Vitamin D-Related Toxicity
Personal Vitamin D Response and Targeted Serum 25(OH)D Concentrations
Vitamin D Deficiency Increases Vulnerability to SARS-CoV-2 Infections
Issues with Published RCTs and Limitations of Data and Interpretation
New Vitamin D Recommendations

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Vitamin D

Vitamin D is a micronutrient with pleiotropic effects in humans. Due to sedentary lifestyles and increasing time spent indoors, a growing body of research is revealing that vitamin D deficiency is a global problem. Despite the routine measurement of vitamin D in clinical laboratories and many years of efforts, methods of vitamin D analysis have yet to be standardized and are burdened with significant difficulties.
78907 Jun 2021

Vitamin D Fortification

By utilizing historical changes in Danish legislation related to mandatory vitamin D fortification of margarine, which was implemented in the mid 1930s and abruptly abandoned in June 1985, the studies in the D-tect project investigated the effects of vitamin D on health outcomes in individuals, who during gestation were exposed or unexposed to extra vitamin D from fortified margarine.
47130 Aug 2021

Vitamin D and Preeclampsia

Preeclampsia (PE) is a set of clinical symptoms that appears after the 20th week of pregnancy. It is a multi-organ disease characterized by hypertension and proteinuria, and in the absence of proteinuria—an impairment of the functions of the internal organs. With regard to the multiple mechanisms of action of Vit D, its deficiency seems to be one of the possible factors conducive to PE development. It has been suggested that the consequence of low Vit D levels may be the appearance of an early, severe form of PE, and its supplementation may be a protective factor against its recurrence in subsequent pregnancies [232]. The relationship between Vit D and PE development may explain its impact on implantation, angiogenesis, and endothelial status, regulation of the immune response, effect on RAAS, and calcium metabolism.
39617 Nov 2021

Vitamin D-dependent Rickets

Vitamin D-dependent rickets is a disorder of bone development that leads to softening and weakening of the bones (rickets).
82023 Dec 2020

Vitamin D and Infertility

Vitamin D plays a crucial role in calcium and phosphate homeostasis, by increasing intestinal calcium absorption and renal calcium reabsorption. For vitamin D, accumulating evidence from observational human studies suggests a key role for both male and female fertility.
39803 Sep 2021

Vitamin D and Glomerulonephritis

Vitamin D presents a plethora of different functions that go beyond its role in skeletal homeo-stasis. It is an efficient endocrine regulator of the Renin–Angiotensin–Aldosterone System (RAAS) and erythropoiesis, exerts immunomodulatory effects, reduces the cardiovascular events and all-cause mortality. In Chronic Kidney Disease (CKD) patients, Vitamin D function is im-paired; the renal hydrolyzation of its inactive form by the action of 1α-hydroxylase declines at the same pace of reduced nephron mass. Moreover, Vitamin D major carrier, the D-binding pro-tein (DBP), is less represented due to Nephrotic Syndrome (NS), proteinuria, and the alteration of the cubilin–megalin–amnionless receptor complex in the renal proximal tubule. In Glomeru-lonephritis (GN), Vitamin D supplementation demonstrated to significantly reduce proteinuria and to slow kidney disease progression. It also has potent antiproliferative and immunomodu-lating functions, contributing to the inhibitions of kidney inflammation. Vitamin D preserves the structural integrity of the slit diaphragm guaranteeing protective effects on podocytes. Acti-vated Vitamin D has been demonstrated to potentiate the antiproteinuric effect of RAAS inhibi-tors in IgA nephropathy and Lupus Nephritis, enforcing its role in the treatment of glomerulo-nephritis: calcitriol treatment, through Vitamin D receptor (VDR) action, can regulate the hepa-ranase promoter activity and modulate the urokinase receptor (uPAR), guaranteeing podocyte preservation. It also controls the podocyte distribution by modulating mRNA synthesis and protein expression of nephrin and podocin. Maxalcalcitol is another promising alternative: it has about 1/600 affinity to vitamin D binding protein (DBP), compared to Calcitriol, overcoming the risk of hypercalcemia, hyperphosphatemia and calcifications, and it circulates principally in un-bound form with easier availability for target tissues. Doxercalciferol, as well as paricalcitol, showed a lower incidence of hypercalcemia and hypercalciuria than Calcitriol. Paricalcitol demonstrated a significant role in suppressing RAAS genes expression: it significantly decreases angiotensinogen, renin, renin receptors, and vascular endothelial growth factor (VEGF) mRNA levels, thus reducing proteinuria and renal damage.
62411 Oct 2021

Vitamin D Deficiency

Vitamin D was found to counteract insulin resistance via participation in the maintenance of normal resting reactive oxygen species level and regulation of Ca2+ level in many cell types.
Both genomic and non-genomic action of vitamin D is directed to insulin signaling. Thereby, vitamin D reduces the extent of pathologies associated with insulin resistance such as oxidative stress and inflammation. Therefore, the beneficial actions of vitamin D include an improvement of glucose and lipid metabolism in insulin-sensitive tissues, and in consequence the diminish of insulin resistance.
89930 Sep 2020

Vitamin D Signaling

The vitamin D metabolite 1α,25-dihydroxyvitamin D3 is the natural, high-affinity ligand of the transcription factor vitamin D receptor (VDR). In many tissues and cell types, VDR binds in a ligand-dependent fashion to thousands of genomic loci and modulates, via local chromatin changes, the expression of hundreds of primary target genes. Thus, the epigenome and transcriptome of VDR-expressing cells is directly affected by vitamin D. Vitamin D target genes encode for proteins with a large variety of physiological functions, ranging from the control of calcium homeostasis, innate and adaptive immunity, to cellular differentiation.
43312 Apr 2022

Vitamin D-Fortified Beverages

Vitamin D is a lipophilic bioactive that plays an important role in bone health. Fortification of beverages, such as milk, fruit juices, teas, and vegetable drinks, could be an efficient strategy to prevent vitamin D deficiency and its associated effects on health.
111728 Apr 2022

Oral Vitamin D Therapy

Vitamin D is an essential nutrient in humans; it is produced by the body through exposure to the sun (the primary source of vitamin D), or more precisely, to mild ultraviolet B (UVB) light.
42709 Aug 2021
Topic Review
Vitamin D in NF1
Vitamin D is a fat-soluble steroid hormone playing a pivotal role in calcium and phosphate homeostasis as well as in bone health. Several investigations indicated that vitamin D action extends far beyond bone health and calcium metabolism, showing broad effects on a variety of critical illnesses, including cancer, infections, cardiovascular and autoimmune diseases. Epidemiological studies indicated that low circulating vitamin D levels inversely correlate with cutaneous manifestations and bone abnormalities, clinical hallmarks of neurofibromatosis type 1 (NF1). NF1 is an autosomal dominant tumour predisposition syndrome causing significant pain and morbidity, for which limited treatment options are available.
72729 Jan 2021

Vitamin D and Cancer

There is strong evidence from geographical ecological and observational studies that solar UVB exposure and serum 25-hydroxyvitamin D concentration are inversely correlated with risk of incidence and death from many types of cancer. Clinical trials have provided limited support for the UVB-vitamin D-cancer hypothesis due to poor design and execution. Many experimental studies in cultured cells and animal models have described a wide range of anticancer effects of vitamin D compounds.
36127 Apr 2022

Vitamin D and Microbiota

Microbiome studies have already demonstrated unique microbial patterns in systemic autoimmune diseases such as inflammatory bowel disease, rheumatoid arthritis, and systemic lupus erythematosus. Dysbiosis also seems to be associated with allergies, in particular asthma, atopic dermatitis, and food allergy.
24528 Oct 2022

Vitamin D Target Genes

The biologically active form of vitamin D3, 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3), modulates innate and adaptive immunity via genes regulated by the transcription factor vitamin D receptor (VDR). In order to identify the key vitamin D target genes involved in these processes, transcriptome-wide datasets were compared, which were obtained from a human monocytic cell line (THP-1) and peripheral blood mononuclear cells (PBMCs) treated in vitro by 1,25(OH)2D3, filtered using different approaches, as well as from PBMCs of individuals supplemented with a vitamin D3 bolus. The led to the genes ACVRL1, CAMP, CD14, CD93, CEBPB, FN1, MAPK13, NINJ1, LILRB4, LRRC25, SEMA6B, SRGN, THBD, THEMIS2 and TREM1. Public epigenome- and transcriptome-wide data from THP-1 cells were used to characterize these genes based on the level of their VDR-driven enhancers as well as the level of the dynamics of their mRNA production.
65715 Apr 2022

Vitamin D on Immune System

Vitamin D deficiency, which causes an imbalance in bone remodeling, is a global public health problem and its frequency is increasing.
39006 Dec 2021

Vitamin D on Skin Aging

The normal vitamin D3 status is important for a general prevention of premature aging maintaining a healthful skin aging. Vitamin D3metabolites including its classical (1,25(OH)2D3) and novel (CYP11A1-intitated) D3hydroxyderivatives exert many beneficial protective effects on the skin, which could influence the process of premature aging via many different mechanisms, leading to a delay or attenuation of both chronological skin aging and photoaging. Skin-resident cells (keratinocytes, fibroblasts, and sebocytes) are capable of locally activating vitamin D3and exhibiting a diverse biological effect such as photoprotection and immunosuppression, similar to the UVR-induced one.

Vitamin D in Brain Health

In the present review a novel role of vitamin D has been described during aging condition, focusing on vitamin D mechanism in brain and how it can help slow down diseases related to neuroinflammation and cognitive decline. In particular vitamin D metabolism and the role of vitamin D receptor (VDR) in brain was underlained. Despite the important role of vitamin D in this context, we discussed the potential effects of curcumin on the health of the central nervous system. Finally we focused on possible treatments triggered by vitamin D and curcumin, especially in neuroprotection and maintaining brain health.
64327 Oct 2020

Vitamin D Metabolism Gene Polymorphisms

Vitamin D is a potent immunonutrient that through its main metabolite calcitriol, regulates the immunomodulation of macrophages, dendritic cells, T and B lymphocytes, which express the vitamin D receptor (VDR), and they produce and respond to calcitriol. Genetic association studies have shown that up to 65% of vitamin D serum variance may be explained due to genetic background.
178201 Jan 2022

Vitamin D Deficiency and T2DM

It seems that vitamin D deficiency may be one of the crucial factors responsible for increased cancer risk among T2DM patients. Vitamin D via alleviation of insulin resistance, hyperglycemia, oxidative stress and inflammation reduces diabetes driven cancer risk factors. Moreover, vitamin D strengthens the DNA repair process, and regulates apoptosis and autophagy of cancer cells as well as signaling pathways involved in tumorigenesis i.e., tumor growth factor β (TGFβ), insulin-like growth factor (IGF) and Wnt-β-Cathenin. It should also be underlined that many types of cancer cells present alterations in vitamin D metabolism and action as a result of Vitamin D Receptor (VDR) and CYP27B1 expression dysregulation.
34822 Jul 2021

Vitamin D arrests cell cycling

Vitamin D is a steroid hormone crucial for bone mineral metabolism. In addition, vitamin D has pleiotropic actions in the body, including anti-cancer actions. These anti-cancer properties observed within in vitro studies frequently report the reduction of cell proliferation by direct alteration of cell cycle regulators which induce cell cycle arrest. The most recurrent reported mode of cell cycle arrest by vitamin D is at the G1/G0 phase of the cell cycle. This arrest is mediated by p21 and p27 upregulation, which results in suppression of cyclin D and E activity which leads to G1/G0 arrest. In addition, vitamin D treatments within in vitro cell lines have observed a reduced C-MYC expression and increased retinoblastoma protein levels that also result in G1/G0 arrest.
70616 Dec 2020

Oral Vitamin D Therapy

Vitamin D in NF1 ( neurofibromatosis)

Vitamin D is a fat-soluble steroid hormone playing a pivotal role in calcium and phosphate homeostasis as well as in bone health. Several investigations indicated that vitamin D action extends far beyond bone health and calcium metabolism, showing broad effects on a variety of critical illnesses, including cancer, infections, cardiovascular and autoimmune diseases. Epidemiological studies indicated that low circulating vitamin D levels inversely correlate with cutaneous manifestations and bone abnormalities, clinical hallmarks of neurofibromatosis type 1 (NF1). NF1 is an autosomal dominant tumour predisposition syndrome causing significant pain and morbidity, for which limited treatment options are available.
72729 Jan 2021

Vitamin D and Cancer

Vitamin D and Microbiota

Vitamin D Target Genes

Vitamin D on Immune System

Vitamin D deficiency, which causes an imbalance in bone remodeling, is a global public health problem and its frequency is increasing.
39006 Dec 2021

Vitamin D arrests cell cycling

Vitamin D, microbiome, and IBD

Inflammatory bowel disease (IBD) is a chronic inflammation of the gastrointestinal tract (GIT), including Crohn’s disease (CD) and ulcerative colitis (UC), which differ in the location and lesion extensions. Both diseases are associated with microbiota dysbiosis, with a reduced population of butyrate-producing species, abnormal inflammatory response, and micronutrient deficiency (e.g., vitamin D hypovitaminosis). Vitamin D (VitD) is involved in immune cell differentiation, gut microbiota modulation, gene transcription, and barrier integrity. Vitamin D receptor (VDR) regulates the biological actions of the active VitD (1α,25-dihydroxyvitamin D3), and is involved in the genetic, environmental, immune, and microbial aspects of IBD. VitD deficiency is correlated with disease activity and its administration targeting a concentration of 30 ng/mL may have the potential to reduce disease activity. Moreover, VDR regulates functions of T cells and Paneth cells and modulates release of antimicrobial peptides in gut microbiota-host interactions. Meanwhile, beneficial microbial metabolites, e.g., butyrate, upregulate the VDR signaling.
59331 Jan 2021

Vitamin D in Dairy Products

The term Vitamin D was created in 1922, describing a vitamin able to promote calcium deposition. Vitamin D in nature is available as ergocalciferol (vitamin D2) or cholecalciferol (vitamin D3).
320405 Nov 2020

Different Vitamin D Supplementation Strategies

Vitamin D (VD) is an essential micronutrient with multiple functions for human growth, and adequate intake should be guaranteed throughout life. However, VD insufficiency is observed in infants all over the world. Low VD concentration in the breast milk of non-supplemented mothers and low compliance to VD daily supplementation are the main causes of VD insufficiency, especially in the long term. Furthermore, VD supplementation dosages are still debated and differ by country. Different dosages and supplementation strategies result in similar VD sufficiency rates. Therefore, international guidelines may be revised in the future to offer multiple and different options of supplementation for specific settings and ages.
31920 Jun 2022

Vitamin D in Cognitive Dysfunction

Vitamin D is necessary for all vertebrates, including humans, to maintain adequate phosphate and calcium levels in the blood, thereby helping to develop normal bone, optimal maintenance of muscle contractions, and cellular functions in different parts of the body. The developmental disabilities induced by vitamin D deficiency (VDD) include neurological disorders (e.g., attention deficit hyperactivity disorder, autism spectrum disorder, schizophrenia) characterized by cognitive dysfunction.
34928 Jul 2022l]

Vitamin D Synthesis and Metabolism

Vitamin D, conventionally considered a nutrient, is a potent hormone regulating many physiological functions. Vitamin D exists as a prohormone that needs to be transformed into biologically active products that bind to their cognate nuclear receptors to regulate diverse physiological processes.
475513 Apr 2022

Vitamin D in Cardiovascular Diseases

Vitamin D represents a group of secosteroids involved in the calcium and phosphate metabolism. The active form of vitamin D, 1,25-dihydroxylcalciferol, exerts its biological mechanisms viura the VDR which acts as a regulator of several target genes.
37524 Jan 2022 [https://encyclopedia.pub/entry/18641|

Vitamin D in Breast Cancer

Vitamin D3, which is well known to maintain calcium homeostasis, plays an important role in various cellular processes. It regulates the proliferation and differentiation of several normal cells, including immune and neoplastic cells, influences the cell cycle, and stimulates cell maturation and apoptosis through a mechanism dependent on the vitamin D receptor (VDR). The involvement of vitamin D3 in breast cancer development has been observed in numerous clinical studies. The effect of vitamin D3 on the development of breast cancer (favorable, ineffective, or even unfavorable) depends on many factors, such as age, menopausal status, or obesity.
20511 Aug 2022

Vitamin D and Endothelial Function

Vitamin D deficiency (VDD) and erectile dysfunction (ED) heavily burden the male population. The higher prevalence of both conditions in the elderly suggests a possible relationship between the two conditions. In addition, in vitro, animal, and human studies have revealed several mechanisms that may relate VDD to ED. The main mechanism by which vitamin D might exert its action on sexual function appears to be through the regulation of endothelial function. Indeed, VDD correlates with several markers of endothelial function. The action of vitamin D on the endothelium would be exercised both indirectly through its intervention in inflammatory processes and through the production of oxygen free radicals, and directly through the regulation of vascular stiffness, the production of nitric oxide, and the regulation of vessel permeability.
13525 Jun 2023

Vitamin D in Sleep Disorders

Vitamin D is a fat-soluble vitamin, mainly synthesized in the body through ultraviolet B (UVB) exposure on the skin or taken orally through food and/or supplements.
41311 Feb 2022

Vitamin D and Infectious Diseases

It is now 2 years since we have seen the impact of the CoronaVirus Disease-19 (COVID-19) caused by Syndrome-Coronavirus-2 worldwide, affecting millions of people and rates of mortality close to 6 million. Although we are beginning to see the real benefit of vaccines, in terms of reduced mortality rates, many individuals still remain to be vaccinated or do not respond to them leaving a large number of patients still experiencing severe respiratory symptoms associated with COVID-19. In recent months, we have seen another surge in individuals infected with COVID-19 and mortality rates are also increasing. In the absence of effective therapies or vaccines, the medical and scientific community have extensively explored a range of current available therapeutic agents, mainly focused on targeting viral replication as well as managing severe respiratory symptoms associated with COVID-19. Vitamin D has emerged as one such candidate due to its recognized immunomodulatory effects. In this regard, the activation of the vitamin D receptor (VDR) signaling pathway may generate beneficial effects in acute respiratory distress syndrome by decreasing the cytokine/chemokine storm, thus having an important immunomodulatory and anti-inflammatory role.
39307 Feb 2022

Vitamin D in Immune System

Recent research has led to an explosion in our interest and our understanding of the role of vitamin D in regulation of immunity. At the molecular level, the hormonal form of vitamin D signals through the nuclear vitamin D receptor (VDR), a ligand-regulated transcription factor. The VDR and vitamin D metabolic enzymes are expressed throughout the innate and adaptive arms of the immune system. The advent of genome-wide approaches to gene expression profiling led to identification of numerous VDR-regulated genes implicated in regulation of innate and adaptive immunity. The molecular data infer that vitamin D signaling should boost innate immunity against pathogens of bacterial or viral origin.
82329 Oct 2020

Vitamin D in Multiple Sclerosis

Multiple sclerosis (MS) is a chronic demyelinating disease of central nervous system and is caused by an aberrant immune response to myelin sheath. Disease-modifying medications, which mainly aim to suppress such aberrant immune response, have significantly improved MS treatment. However, the disease severity continues to worsen. In contrast, progressively more data suggest that 1,25-dihydroxyvitamin D or 1,25(OH)2D, i.e., the active vitamin D, suppresses the differentiation of potentially pathogenic T cells associated with MS, enhances the differentiation of regulatory T cells that suppress the pathogenic T cells, and promotes remyelination. These novel 1,25(OH)2D functions have encouraged investigators to develop vitamin D as a potential therapy for MS. However, because of the hypercalcemia that is associated with high 1,25(OH)2D concentrations, supplementation of native vitamin D has been a major focus in clinical trials for the treatment of MS, but such trials have produced mixed data. In this article, we will review current progress in the supplementation of different vitamin D forms for the treatment of experimental autoimmune encephalomyelitis (i.e., an MS animal model) as well as MS.
60528 Oct 2020

Vitamin D against COVID-19

Many studies suggest that vitamin D improves immune function, reducing susceptibility to infection. In contrast, an extensive number of scientific studies highlight its immunosuppressive effects. Thus, it seems that vitamin D supports immune response under physiological conditions, but it also has an active role in autoimmunity prevention. In short, its effects would depend on the immunological situation of the patient.
35030 Dec 2021

Skeletal Muscle and Vitamin D

Vitamin D, unlike the micronutrients, vitamins A, E, and K, is largely obtained not from food but by the action of solar ultraviolet light on its precursor, 7-dehydrocholesterol, in skin. With the decline in UV light intensity in winter, most skin production of vitamin D occurs in summer. Since no defined storage organ or tissue has been found for vitamin D, it has been assumed that an adequate vitamin D status in winter can only be maintained by oral supplementation. Skeletal muscle cells have now been shown to provide an extravascular conservation site for 25-hydroxyvitamin D, which cycles between blood and muscle accounting for its long residence time in blood. In winter, this conservation mechanism appears to be upregulated by parathyroid hormone; a process that appears to have evolved to maintain adequate vitamin D status when vitamin D supply falls.
48317 Nov 2020

Vitamin D and Rheumatic Diseases

Vitamin D plays an important role in maintaining a healthy mineralized skeleton. It is also considered an immunomodulatory agent that regulates innate and adaptive immune systems. The aim of this narrative review is to provide general concepts of vitamin D for the skeletal and immune health, and to summarize the mechanistic, epidemiological, and clinical evidence on the relationship between vitamin D and rheumatic diseases. Multiple observational studies have demonstrated the association between a low level of serum 25-hydroxyvitamin D [25(OH)D] and the presence and severity of several rheumatic diseases, such as rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), spondyloarthropathies, and osteoarthritis (OA). Nevertheless, the specific benefits of vitamin D supplements for the treatment and prevention of rheumatic diseases are less accepted as the results from randomized clinical trials are inconsistent, although some conceivable benefits of vitamin D for the improvement of disease activity of RA, SLE, and OA have been demonstrated in meta-analyses. It is also possible that some individuals might benefit from vitamin D differently than others, as inter-individual difference in responsiveness to vitamin D supplementation has been observed in genomic studies. Although the optimal level of serum 25(OH)D is still debatable, it is advisable it is advisable that patients with rheumatic diseases should maintain a serum 25(OH)D level of at least 30 ng/mL (75 nmol/L) to prevent osteomalacia, secondary osteoporosis, and fracture, and possibly 40–60 ng/mL (100–150 nmol/L) to achieve maximal benefit from vitamin D for immune health and overall health.
49222 Nov 2021

Vitamin D and Skeletal Muscle

Aging is associated with impairment in skeletal muscle mass and contractile function, predisposing to fat mass gain, insulin resistance and diabetes. At cell and animal levels, that VitD treatments had positive effects on the development of muscle fibres in cells in culture, skeletal muscle force and hypertrophy.
31322 May 2021

Vitamin D and Non-Melanoma Skin Cancer

Non-melanoma skin cancers (NMSC) are the most common type of skin malignancies among humans (particularly fair-skinned populations of European descent) and its incidence rates have been on the rise globally for decades [1]. The best defined role of vitamin D in humans is in supporting the normal development and maintenance of bone tissues and in regulating calcium metabolism [7,8]. Furthermore, there is growing evidence that vitamin D plays a role in many fundamental biological processes (e.g., cell proliferation, angiogenesis, and modulation of the immune system) [9] implicated in carcinogenesis.
27726 Oct 2021

Vitamin D in the Context of Evolution

For at least 1.2 billion years, eukaryotes have been able to synthesize sterols and, therefore, can produce vitamin D when exposed to UV-B. Vitamin D endocrinology was established some 550 million years ago in animals, when the high-affinity nuclear receptor VDR (vitamin D receptor), transport proteins and enzymes for vitamin D metabolism evolved. This enabled vitamin D to regulate, via its target genes, physiological process, the first of which were detoxification and energy metabolism. In this way, vitamin D was enabled to modulate the energy-consuming processes of the innate immune system in its fight against microbes. In the evolving adaptive immune system, vitamin D started to act as a negative regulator of growth, which prevents overboarding reactions of T cells in the context of autoimmune diseases. When, some 400 million years ago, species left the ocean and were exposed to gravitation, vitamin D endocrinology took over the additional role as a major regulator of calcium homeostasis, being important for a stable skeleton.
23029 Jul 2022

Vitamin D and Type 2 Diabetes

The management and early treatment of type 2 diabetes (T2D) are essential to prevent further complications involving loss of quality of life and premature death. It is unclear whether vitamin D deficiency might be contributing to an increased T2D risk. A vast body of evidence associates vitamin D deficiency and T2D. This relationship could be mediated by the direct and indirect effects of vitamin D on glucose homeostasis such as insulin secretion, insulin sensitivity, and systemic inflammation.
10808 Aug 2023

Vitamin D and CKD with Bone Disorder

Chronic kidney disease (CKD) is a highly prevalent condition worldwide in which the kidneys lose many abilities, such as the regulation of vitamin D (VD) metabolism. Moreover, people with CKD are at a higher risk of multifactorial VD deficiency, which has been extensively associated with poor outcomes, including bone disease, cardiovascular disease, and higher mortality.
32919 Apr 2023

Vitamin D for COVID-19 Vaccination

Severe acute respiratory syndrome coronavirus 2 is a new, highly pathogenic virus that has recently elicited a global pandemic called the 2019 coronavirus disease (COVID-19). COVID-19 is characterized by significant immune dysfunction, which is caused by strong but unregulated innate immunity with depressed adaptive immunity. Reduced and delayed responses to interferons (IFN-I/IFN-III) can increase the synthesis of proinflammatory cytokines and extensive immune cell infiltration into the airways, leading to pulmonary disease. The development of effective treatments for severe COVID-19 patients relies on our knowledge of the pathophysiological components of this imbalanced innate immune response. Strategies to address innate response factors will be essential. Significant efforts are currently underway to develop vaccines against SARS-CoV-2. COVID-19 vaccines, such as inactivated DNA, mRNA, and protein subunit vaccines, have already been applied in clinical use. Various vaccines display different levels of effectiveness, and it is important to continue to optimize and update their composition in order to increase their effectiveness. However, due to the continuous emergence of variant viruses, improving the immunity of the general public may also increase the effectiveness of the vaccines. Many observational studies have demonstrated that serum levels of vitamin D are inversely correlated with the incidence or severity of COVID-19. Extensive evidence has shown that vitamin D supplementation could be vital in mitigating the progression of COVID-19 to reduce its severity. Vitamin D defends against SARS-CoV-2 through a complex mechanism through interactions between the modulation of innate and adaptive immune reactions, ACE2 expression, and inhibition of the renin-angiotensin system (RAS).

Vitamin D Status and Allergy Outcomes

The very early onset of allergic diseases points to the specific vulnerability of the developing immune system to environmental changes and the development of primary intervention strategies is crucial to address this unparalleled burden. Vitamin D is known to have immunomodulatory functions. While allergic disease is multifactorial, associations with reduced sunlight exposure have led to the hypothesis that suboptimal vitamin D levels during critical early periods may be one possible explanation. Interventions to improve vitamin D status, especially in early life, may be the key to allergic disease prevention.
30928 Apr 2022

Vitamin D Deficiency Status in Malaysia

Vitamin D is essential for maintaining serum calcium levels, ensuring sufficient bone mineralization, immunomodulatory properties, and a protective effect on the cardiovascular system, renal disease, cancer, as well as in pregnancy. Vitamin D deficiency can be managed with pharmacological or non-pharmacological approaches, depending on the severity. The objective is to raise serum vitamin D to a normal level, hence, relieving the symptoms and reducing the adverse health outcomes. Despite no clear guidelines in treating vitamin D deficiency in Malaysia, this condition can be prevented with taking adequate vitamin D in food resources, sun exposure, or supplementation. Special attention should be given to high-risk groups including infants, obese patients, and the elderly.
48311 Feb 2022

Polymorphisms in Vitamin D-Related Genes

Vitamin D deficiency represents a major healthcare problem. Vitamin D status is influenced by genetic and environmental determinants. Several observational studies have evaluated the association of single-nucleotide polymorphisms (SNPs) in vitamin D-related genes and vitamin D levels. Nevertheless, little is known about the role of these SNPs in the response to vitamin D supplementation. We conducted an interventional study to define the association between SNPs in vitamin D-related genes and the response to vitamin D supplementation in 100 self-reported healthy women of Arab ancestry for the majority. Methods. A total of 100 healthy female subjects received a weekly oral dose of 50,000 IU vitamin D for 12 weeks. Serum vitamin D concentration and metabolic profiles were measured at baseline and 12 weeks post-vitamin D supplementation. The genotypes of 37 SNPs selected from previously reported vitamin D-related genes have been assessed by Fluidigm genotyping assay. Results. Rs731236 (VDR gene) and rs7116978 (CYP2R1 gene) showed a significant association with vitamin D status. The rs731236 GG genotype and the rs7116978 CC genotype were associated with a “vitamin D sufficiency” state. Rs731236 GG and rs7116978 CC genotypes showed a higher response to vitamin D supplementation. Transcription factor binding site prediction analysis showed altered binding sites for transcription factors according to the different rs7116978 alleles. Interestingly, the 37 SNPs previously established to play a role in vitamin D-related pathways explained very little of the response to vitamin D supplementation in our cohort, suggesting the existence of alternative loci whose number and effect size need to be investigated in future studies. Conclusion. In this paper, we present novel data on vitamin D-related SNPs and response to vitamin D supplementation demonstrating the feasibility of applying functional genomic approaches in interventional studies to assess individual-level responses to vitamin D supplementation.
54131 Aug 2020

Vitamin D Signaling in Gastro-Rheumatology

Vitamin D has been recently pointed out, and abnormalities of the vitamin D axis have been described in both in vitro and in vivo models of inflammatory bowel diseases (IBD) and arthritis.
29229 Apr 2021

Vitamin D in Oral Diseases Development

Vitamin D is a fat-soluble secosteroid that plays a significant role in the whole body, including the maxillofacial region. The discovery of its receptors in many cells and organs made it possible to reveal the participation of vitamin D not only in the regulation of calcium phosphate metabolism, but also in immune processes, in providing anti-inflammatory and antimicrobial effects, slowing down cell proliferation and stimulating differentiation. In this literature review, we demonstrate the association between low vitamin D levels and the development of recurrent aphthous stomatitis, the course and response to treatment of squamous cell carcinoma of the oral cavity, the severity of periodontal diseases, and the processes of osseointegration and bone remodeling during dental implantation and guided tissue regeneration.
35417 Nov 2021

Vitamin D and Inflammation in Obesity

Obesity affects more than one billion people worldwide and often leads to cardiometabolic chronic comorbidities. It induces senescence-related alterations in adipose tissue, and senescence is closely linked to obesity. Fully elucidating the pathways through which vitamin D exerts anti-inflammatory effects may improve our understanding of local adipose tissue inflammation and the pathogenesis of metabolic disorders.
3402 Jan 2024

Vitamin D Serum Concentrations and COVID-19

Active vitamin D [1,25(OH)2D3—calcitriol] is a secosteroid hormone whose receptor is expressed on all cells of the immune system. Vitamin D has a global anti-inflammatory effect and its role in the management of a SARS-CoV-2 infection has been investigated since the beginning of the COVID-19 pandemic.
19723 Nov 2022

Relationship between Vitamin D and Insulin Resistance

Vitamin D seems to be involved in infections, autoimmune diseases, cardiometabolic diseases, and cancer development. The relationship between vitamin D and insulin resistance has been a topic of growing interest. Low 25-hydroxyvitamin D (25(OH)D) levels appear to be associated with most of the insulin resistance disorders described to date. In fact, vitamin D deficiency may be one of the factors accelerating the development of insulin resistance. Vitamin D deficiency is a common problem in the population and may be associated with the pathogenesis of diseases related to insulin resistance, such as obesity, diabetes, metabolic syndrome (MS) and polycystic ovary syndrome (PCOS). An important question is the identification of 25(OH)D levels capable of generating an effect on insulin resistance, glucose metabolism and to decrease the risk of developing insulin resistance related disorders.
8508 Aug 2023

Vitamin D in Cardiovascular Risk and Disease

Beyond its key role in calcium homeostasis, vitamin D has been found to significantly affect the cardiovascular (CV) system. In fact, low vitamin D levels have been associated with increased CV risk, as well as increased CV morbidity and mortality. The majority of effects of this molecule are related directly or indirectly to its antioxidative and anti-inflammatory properties. Generally, vitamin D insufficiency is considered for 25-hydroxyvitamin D (25(OH)D) levels between 21–29 ng/mL (corresponding to 52.5–72.5 nmol/L), deficiency as 25(OH)D levels less than 20 ng/mL (<50 nmol/L), and extreme deficiency as 25(OH)D less than 10 ng/mL (<25 nmol/L). However, the definition of an optimal vitamin D status, as defined by 25(OH)D, remains controversial for many extra-bone conditions, including CV disease.
17015 Jun 2023

Achieving Optimum Clinical Outcomes with Vitamin D

Musculoskeletal benefits of vitamin D include calcium homeostasis, bone mineralization, etc., through its hormonal actions. This requires serum 25(OH)D less than 20 ng/mL. In contrast, many other tissues require above 30 or 40 ng/mL steady-state concentrations. To reduce infections, autoimmune diseases, cancer, and all-cause mortality require a minimum level of 50 ng/mL. Vitamin D is an economical and widely available (generic) nutrient obtained over the counter without a prescription. At the recommended doses, vitamin D does not cause any adverse effects. Disease prevention and minimizing complications and premature deaths can be achieved by maintaining serum 25(OH)D concentrations between 50 and 80 ng/mL. This costs less than 0.01% of the cost of one day of hospitalization.
21621 Sep 2023

Ethnic Differences in Vitamin-D Metabolism

Vitamin D requirements vary from one human population to another. This is because the capacity to synthesize vitamin D in the skin also varies as a result of differences in solar UV or skin pigmentation. There has consequently been natural selection to use this vitamin more efficiently in populations that live at higher latitudes or are darker-skinned.
75326 Oct 2020

Evolution of the Vitamin D Receptor

The evolution of the vitamin D receptor started millions of years ago, with earliest evidence of the receptor in existing organisms tracing back to the sea lamprey (Petromyzon marinus). The vitamin D receptor is an example of a nuclear receptor, which binds vitamin D, and modulates the transcription of various target genes appropriately. Early in the history of life on Earth, nuclear receptors would have been selected for due to the strong pressure for organisms to respond to their environment. This eventually lead to the evolution of nuclear receptor families, such as the NR1H and NR1I families, capable of binding nutritional ligands and modulating transcription appropriately. Each of these families host a variety of receptors, including the vitamin D receptor, but all are thought to have originated from one ancestral receptor. Through major gene duplications and variable selective pressures, the various receptors within these families evolved, each one accommodating cholesterol derivatives, such as oxysterols, bile acids, and vitamin D.
27421 Nov 2022

Vitamin D in Long COVID-19

Coronavirus disease 2019 (COVID-19) has quickly become a global pandemic. Reports from different parts of the world indicate that a significant proportion of people who have recovered from COVID-19 are suffering from various health problems collectively referred to as “long COVID-19”. Common symptoms include fatigue, shortness of breath, cough, joint pain, chest pain, muscle aches, headaches, and so on. Vitamin D is an immunomodulatory hormone with proven efficacy against various upper respiratory tract infections. Vitamin D can inhibit hyperinflammatory reactions and accelerate the healing process in the affected areas, especially in lung tissue. Moreover, vitamin D deficiency has been associated with the severity and mortality of COVID-19 cases, with a high prevalence of hypovitaminosis D found in patients with COVID-19 and acute respiratory failure. However, no evidence has been found to support a role of vitamin D supplementation in reducing symptoms of long-COVID-19. On the other hand, having a higher vitamin D level before SARS-CoV-2 infection or raising it rapidly at the first symptoms of infection can significantly reduce the risk and severity of COVID-19.
236129 Apr 2022

PPARs and Vitamin D Receptor in Cancer

Peroxisome proliferator-activated receptors (PPARs) are members of the superfamily of nuclear hormone receptors, which respond to specific ligands such as polyunsaturated fatty acids by altering gene expression. Three subtypes of this receptor have been discovered, each evolving to achieve different biological functions. Like other nuclear receptors, the transcriptional activity of PPARs is affected not only by ligand-stimulation, but also by cross-talk with other molecules. For example, both PPARs and the RXRs are ligand-activated transcription factors that coordinately regulate gene expression. In addition, PPARs and vitamin D receptor (VDR) signaling pathways regulate a multitude of genes that are of importance for cellular functions including cell proliferation and cell differentiation. Interaction of the PPARs and VDR signaling pathways has been shown at the level of molecular cross-regulation of their transcription factor. A variety of ligands influencing the PPARs and VDR signaling pathways have been shown to reveal chemopreventive potential by mediating tumor suppressive activities in human cancers.
6908 Sep 2023

Impact of Vitamin D in Tuberculosis

Vitamin D plays a crucial role in many infectious diseases, such as tuberculosis (TB), that remains one of the world’s top infectious killers with 1.5 million deaths from TB in 2021. Vitamin D suppresses the replication of Mycobacterium tuberculosis in vitro and showed a promising role in TB management as a result of its connection with oxidative balance.
27727 Apr 2022

Vitamin D May Protect against Breast Cancer

In general, the protective effect of vitamin D3 against breast cancer is underlined by inhibition of proliferation and migration, stimulation of differentiation and apoptosis, and inhibition of epithelial/mesenchymal transition in breast cells. Vitamin D3 may also inhibit the transformation of normal mammary progenitors into breast cancer stem cells that initiate and sustain the growth of breast tumors. As long noncoding RNAs (lncRNAs) play an important role in breast cancer pathogenesis, and the specific mechanisms underlying this role are poorly understood, we provided several arguments that vitamin D3/VDR may induce protective effects in breast cancer through modulation of lncRNAs that are important for breast cancer pathogenesis.
30601 Apr 2022

Vitamin D and Its Neuroimmunological Roles

Vitamin D consists of a group of structurally related secosteroids, including cholecalciferol, ergocalciferol, 25-hydroxyvitamin D (25(OH)D, calcidiol), and 1,25-dihydroxyvitamin D (1,25(OH)2D, calcitriol). Vitamin D, a fat-soluble neuroactive prohormone, is increasingly recognized as not only a marker of overall health but also a necessary neurosteroid and immunomodulator, exerting pleiotropic effects on the neurological system.
4715 Sep 2023

Treatment of Vitamin D Deficiency with Calcifediol

Calcifediol (25-OH-vitamin D3) is the prohormone of the vitamin D endocrine system. It is used to prevent and treat vitamin D deficiency. Calcifediol, as well as cholecalciferol (vitamin D3), is efficient and safe in the general population, although calcifediol has certain advantages over cholecalciferol, such as its rapid onset of action and greater potency.
50720 May 2022

Vitamin D—Innate and Acquired Immunity

Globally, vitamin D deficiency is a significant public health problem—a pandemic—that has overtaken iron deficiency as the most common nutritional deficiency in the world. Vitamin D deficiency is associated with many chronic diseases and increases the risk of acute and worsened chronic infections. Both vitamin D and [25(OH]D: calcifediol) and its active form, 1,25-dihydroxyvitamin D [1,25(OH)2D: calcitriol], play critical roles in protecting humans from invasive pathogens, reducing risks of autoimmunity, and maintaining better health. Conversely, low 25(OH)D status increases susceptibility to infections and developing autoimmunity. Individuals obtain optimal results by maintaining serum 25(OH)D concentrations above 50 ng/mL (125 nmol/L) (above 40 ng/mL in the population): this also minimizes community outbreaks and autoimmune disorders. In over 97.5% of people, this can be achieved through daily sun exposure (except in countries far from the equator during winter) or taking between 5,000 and 8,000 IU vitamin D supplements daily (average, ~70 to 90 IU/kg body weight). Only those with gastrointestinal malabsorption, obesity, or on medications that increase catabolism of vitamin D, and a few specific disorders require higher intake.
37006 Sep 2023

Mast Cells and Vitamin D Status

The immune system is made up by an extremely composite group of cells, whose regulated and harmonious activity is fundamental to maintain health. The mast cells are an essential effector of inflammatory response which is characterized by a massive release of mediators accumulated in cytoplasmic secretory granules. However, beyond the effects on immune response, mast cells can modify bone metabolism and are capable of intervening in the genesis of pathologies such as osteoporosis and osteopenia. Vitamin D is recognized to induce changes in bone metabolism, but it is also able to influence immune response, suppressing mast cell activation and IgE synthesis from B cells and increasing the number of dendritic cells and IL-10-generating regulatory T cells.
17805 Jun 2023

Vitamin D Metabolism in Celiac Disease

Celiac disease is a chronic autoimmune disorder involving the small intestine, characterized by villous atrophy, crypt hyperplasia and an increase in intraepithelial lymphocytes. Due to both calcium malabsorption and immune activation, a high prevalence of bone mass derangement is evident in this condition, regardless of the presence of overt malabsorption. In untreated patients, secondary hyperparathyroidism is responsible for the hyperconversion of 25-vitamin D into 1,25-vitamin D making mandatory the determination of serum levels of both vitamin metabolites to avoid a wrong diagnosis of vitamin D deficit. A gluten-free diet allows for a normalization of bone and mineral metabolism, reverting these abnormalities and raising some doubts on the need for vitamin supplementation in all the patients.
46219 Jan 2023

Vitamin D Deficiency and Psychiatric Pathology

Vitamin D functions have been studied progressively, and along with their main role in regulating calcium homeostasis, the potential function in the nervous system and the link between different psychiatric disorders and vitamin D deficiency have been revealed. The discovery of vitamin D receptors in multiple brain structures, like the hippocampus, led to the hypothesis that vitamin D deficiency could be responsible for treatment resistance in psychiatric diseases.
4530 Nov 2023

Vitamin D and Primary Ciliary Dyskinesia

Primary ciliary dyskinesia (PCD) is a genetic disease characterized by abnormalities in ciliary structure/function. Low plasmatic level of this vitamin is present in the PCD population. The utility of vitamin D supplementation may be essential in this group of individuals.
50204 Nov 2021

Vitamin D, Sun Exposure and Skin Cancer

The current vitamin D deficiency epidemic is accompanied by an increase in endemic skin cancer. Ultraviolet (UV) exposure (neither artificial nor natural) is not the ideal source to synthesize vitamin D. There is conflicting epidemiological evidence regarding vitamin D, non-melanoma skin cancer (NMSC), and cutaneous melanoma (CMM), confounded by the effect of sun exposure and other factors.
27629 Mar 2022

Vitamin D, Oxidative-Stress and Aging

Recent advances in vitamin D research indicate that this vitamin, a secosteroid hormone, has beneficial effects on several body systems other than the musculoskeletal system. Both 25 dihydroxy vitamin D [25(OH)2D] and its active hormonal form, 1,25-dihydroxyvitamin D [1,25(OH)2D] are essential for human physiological functions, including damping down inflammation and the excessive intracellular oxidative stresses. Vitamin D is one of the key controllers of systemic inflammation, oxidative stress and mitochondrial respiratory function, and thus, the aging process in humans. In turn, molecular and cellular actions form 1,25(OH)2D slow down oxidative stress, cell and tissue damage, and the aging process. On the other hand, hypovitaminosis D impairs mitochondrial functions, and enhances oxidative stress and systemic inflammation. The interaction of 1,25(OH)2D with its intracellular receptors modulates vitamin D–dependent gene transcription and activation of vitamin D-responsive elements, which triggers multiple second messenger systems. Thus, it is not surprising that hypovitaminosis D increases the incidence and severity of several age-related common diseases, such as metabolic disorders that are linked to oxidative stress. These include obesity, insulin resistance, type 2 diabetes, hypertension, pregnancy complications, memory disorders, osteoporosis, autoimmune diseases, certain cancers, and systemic inflammatory diseases. Vitamin D adequacy leads to less oxidative stress and improves mitochondrial and endocrine functions, reducing the risks of disorders, such as autoimmunity, infections, metabolic derangements, and impairment of DNA repair; all of this aids a healthy, graceful aging process. Vitamin D is also a potent anti-oxidant that facilitates balanced mitochondrial activities, preventing oxidative stress-related protein oxidation, lipid peroxidation, and DNA damage. New understandings of vitamin D-related advances in metabolomics, transcriptomics, epigenetics, in relation to its ability to control oxidative stress in conjunction with micronutrients, vitamins, and antioxidants, following normalization of serum 25(OH)D and tissue 1,25(OH)2D concentrations, likely to promise cost-effective better clinical outcomes in humans.
161529 Oct 2020

The Relationship between Vitamin D and Estrogens

Vitamin D has a potential role of regulating many cellular functions. The totality of vitamin D transport depends on the activity of vitamin D binding protein (DBP) and albumin in a measure of 85% and 15%, respectively. Vitamin D is found in the free circulating form in percentages ranging from 0.01% to 3%. Both DBP and albumin are synthesized by the liver, and their production is regulated by estrogens, glucocorticoids, and inflammatory cytokines.
10411 Jul 2023

Effects of Vitamin D on Satellite Cells

Vitamin D is a micronutrient that plays a role in the homeostasis of various body organs, including skeletal muscle. Skeletal muscle growth and regeneration are critically affected by satellite cells, skeletal muscle stem cells. The discovery of vitamin D receptors on satellite cells supports the role of vitamin D in regulating satellite cell function. In vivo studies have shown the effect of vitamin D on skeletal muscle growth in early life, muscle homeostasis in aging, and skeletal muscle regeneration in conditions of muscle injury or chronic disease.
49110 Nov 2022

Nutritional Considerations during Spaceflights

The main nutritional concerns during a spaceflight include the sufficient provision of energy to counteract the negative energy balance, which is often experienced by astronauts, the prevention of a deficiency in micronutrients, and fluid and sodium management. Furthermore, of utmost importance is the provision of specific nutrients to face spaceflight-induced pathophysiological events.
26728 Nov 2022

Considerations about PD Treatment

The treatment of PD starts when motor signs are developed. Current treatments include pharmacologic therapy, physical therapy, rehabilitating therapy and surgery. Physical therapy and exercise are beneficial in PD patients for both motor and non-motor symptoms. The activities include speech therapy, nutrition, physiotherapy, and support groups.
28020 Apr 2021

Clinical Considerations of Benzodiazepines

Benzodiazepines (BZDs) are among one of the most widely prescribed drug classes in the United States. BZDs are a class of psychoactive drugs known for their depressant effect on the central nervous system (CNS). They quickly diffuse through the blood–brain barrier to affect the inhibitory neurotransmitter GABA and exert sedative effects. One of the debilitating side effects of BZDs is their addictive potential. The dependence on BZDs generally leads to withdrawal symptoms, requiring careful tapering of the medication when prescribed. Regular use of BZDs has been shown to cause severe, harmful psychological and physical dependence, leading to withdrawal symptoms similar to that of alcohol withdrawal.
33123 Dec 2021

Melatonin Usage and Considerations

Exogenous melatonin is commonly used to treat insomnia, other sleep problems, and numerous medical illnesses, including Alzheimer’s disease, autism spectrum disorder, and mild cognitive impairment in adults and children. There is evolving information regarding issues with the use of chronic melatonin.
25524 Mar 2023

Vitamin D and Diseases in KSA and UAE

Accumulating evidence supports the potential protective effects of vitamin D against chronic diseases such as Alzheimer’s disease, autoimmune diseases, cancers, cardiovascular disease (ischaemic heart disease and stroke), type 2 diabetes, hypertension, chronic kidney disease, stroke, and infectious diseases such as acute respiratory tract diseases, COVID-19, influenza, and pneumonia, as well as adverse pregnancy outcomes. The respective evidence is based on ecological and observational studies, randomized controlled trials, mechanistic studies, and Mendelian randomization studies. However, randomized controlled trials on vitamin D supplementation have largely failed to show benefits, probably due to poor design and analysis.
25127 Apr 2023

Vitamin D and SIRT1 in Non-Communicable Diseases

Vitamin D and SIRT1 have direct and indirect influence of the regulation of transcription and epigenetic changes and are related to cytoplasmic signaling pathways such as PLC/DAG/IP3/PKC/MAPK, MEK/Erk, insulin/mTOR/cell growth, proliferation; leptin/PI3K-Akt-mTORC1, Akt/NFĸB/COX-2, NFĸB/TNFα, IL-6, IL-8, IL-1β, and AMPK/PGC-1α/GLUT4, among others. Several vitamin D metabolites are generated in the liver, the kidney, and in other tissue types, which are then excreted in the urine. The most investigated and important forms are 24-hydroxylated (i.e., 24,25-dihydroxyvitamin D3, 1,24,25-trihydroxyvitamin D3); these forms are converted from 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3, respectively. CYP24A1 24-hydroxylase enzyme, which is responsible for these conversions—similarly to CYP27B1, a multicomponent enzyme in the mitochondria—is regulated by calcium, phosphorus, and 1,25-dihydroxyvitamin D3 through VDR, the receptor of vitamin D. Long-term imbalance in this system or an inappropriate amount of cytochrome P450 enzymes—which control the production, regulation, and degradation of vitamin D—can cause vitamin D insufficiency-related diseases. Thus, abnormally elevated levels of CYP24A1 can create a deficit in vitamin D levels, since this enzyme is uniquely responsible for the catabolism of vitamin D. Elevated levels of CYP24A1 are observed in breast, prostate, esophageal, colon, and lung cancers, genetically linked hypophosphatemia, diabetic nephropathy, and chronic kidney disease (CKD). Deficiency of vitamin D can also develop due to an inadequate amount of sun exposure and insufficient nutritional supplementation, or it can appear as a result of certain diseases, e.g., diabetes, cancer, chronic kidney disease, or genetically linked hypophosphatemia.
21728 Apr 2023

Effects of Vitamin D on the Immune System

Vitamin D intervenes in calcium and phosphate metabolism and bone homeostasis. Experimental studies have shown that 1,25-dihydroxyvitamin D (calcitriol) generates immunologic activities on the innate and adaptive immune system and endothelial membrane stability. Low levels of serum 25-hydroxyvitamin D (25(OH)D) are associated with an increased risk of developing immune-related diseases such as psoriasis, type 1 diabetes, multiple sclerosis, and autoimmune diseases.
30913 Sep 2022

Vitamin D and Resveratrol Performances in COVID-19

A variety of observational epidemiological studies have reported that vitamin D deficiency is often a crucial factor in many inflammatory diseases and autoimmune diseases, as well as the susceptibility to contract infectious diseases, including acute respiratory infections. Similarly, resveratrol regulates immunity, modifying the gene expression and the release of proinflammatory cytokines in the immune cells. Therefore, it plays an immunomodulatory role that can be beneficial in the prevention and development of non-communicable diseases associated with inflammation. Since both vitamin D and resveratrol also act as immunomodulators in inflammatory pathologies, many studies have paid particular attention to an integrated treatment of either vitamin D or resveratrol in the immune reaction against SARS-CoV-2 infections.
9928 Jun 2023

Oligodendrocytes and Vitamin D Neuroprotection in Multiple Sclerosis

Multiple sclerosis (MS) is a complex neurological condition that involves both inflammatory demyelinating and neurodegenerative components. MS research and treatments have traditionally focused on immunomodulation, with less investigation of neuroprotection, and this holds true for the role of vitamin D in MS. Vitamin D plays an anti-inflammatory role in modulating the immune system in MS. More recently, researchers have begun investigating the potential neuroprotective role of vitamin D in MS, which may be important in remyelination and/or the prevention of demyelination. There is a growing body of research uncovering mechanistic role of vitamin D-mediated neuroprotection, including: enhancing oligodendrocyte lineage differentiation, enhancing neurotrophin expression, attenuating aberrant microglial and reactive astrocyte activation, stabilizing the BBB, and reducing oxidative stress. 1,25(OH)2D3 promotes stem cell proliferation and drives the differentiation of neural stem cells into oligodendrocytes, which carry out remyelination.
15624 Oct 2023

Consensus on the Prevention of Vitamin D Deficiency

Vitamin D is crucial for musculoskeletal health, as it plays an important role in the regulation of bone and mineral metabolism, and it can prevent and cure nutritional rickets and osteomalacia. In addition, vitamin D receptor (VDR) expression in almost all human cells suggests, or even documents, a more widespread role of vitamin D for overall health, a notion that is supported by several experimental and epidemiological studies. While there still exist knowledge gaps and controversy regarding potential extra-skeletal effects of vitamin D, there is a wide consensus that the high worldwide prevalence of vitamin D deficiency is of concern and requires actions to improve this situation.
47422 Apr 2022

The Role Vitamin D Reducing Risk Inflammatory Disease

Numerous pleiotropic effects have been reported for vitamin D (vit D) since its discovery a century ago. Today it is well known that in addition to its pivotal role in calcium homeostasis and bone metabolism, vit D has antibacterial, anti-proliferative, immunomodulatory, and anti-inflammatory actions, among other beneficial properties. In the context of inflammatory-based diseases, vit D and its receptor VDR might fulfil their roles as gene regulators through direct gene regulation and epigenetic mechanisms.
30801 Mar 2023

Links between Epigenetics, COVID-19 Infection, and Vitamin D

The highly transmittable and infectious COVID-19 remains a major threat worldwide, with the elderly and comorbid individuals being the most vulnerable. While vaccines are currently available, therapeutic drugs will help ease the viral outbreak and prevent serious health outcomes. Epigenetic modifications regulate gene expression through changes in chromatin structure and have been linked to viral pathophysiology. Since epigenetic modifications contribute to the life cycle of the virus and host immune responses to infection, epigenetic drugs are promising treatment targets to ameliorate COVID-19. Deficiency of the multifunctional secosteroid hormone vitamin D is a global health threat. Vitamin D and its receptor function to regulate genes involved in immunity, apoptosis, proliferation, differentiation, and inflammation. Amassed evidence also indicates the biological relations of vitamin D with reduced disease risk, while its receptor can be modulated by epigenetic mechanisms. The immunomodulatory effects of vitamin D suggest a role for vitamin D as a COVID-19 therapeutic agent.
29623 Nov 2022

Polycystic Ovary Syndrome Physiopathology and Vitamin D Deficiency

Women with PCOS (polycystic ovary syndrome) are deficient in VD, particularly those with a higher weight. Hypovitaminosis is a risk factor for glucose intolerance, and reduced levels of VD is associated with insulin resistance and increased diabetes risk. Since women with PCOS and hirsutism seem to have lower levels of VD than women with PCOS without hirsutism, a correlation between VD deficiency and hyperandrogenism may be suggested. Interestingly, VD is crucial for many human physiological functions, including to counteract inflammation and oxidative stress. Some studies evaluated effects of VD supplementation on glucose homeostasis variables, hormonal status, lipid concentrations, and biomarkers of inflammation and oxidative stress among VD-deficient women. Moreover, VD has been shown to play a role in egg quality and fertility.
38626 Aug 2022

Mechanisms of Vitamin D—Controlling Infections and Autoimmunity

Vitamin D is critical in protecting humans from hyper-inflammation, invasive pathogens, and autoimmunity risks and in maintaining good health. In contrast, low 25(OH)D status increases susceptibility to infections and developing autoimmunity. Data strongly suggested that maintaining serum 25(OH)D concentrations of more than 50 ng/mL is associated with significant risk reduction from viral and bacterial infections, sepsis, and autoimmunity. This is because, above this level, immune cells get sufficient diffusion of vitamin D and 25(OH)D from the circulation to generate intracellular calcitriol for their biological and physiological actions. Vitamin D deficiency treatment costs less than 0.01% of the cost of investigating worsening comorbidities associated with hypovitaminosis D. Despite cost-benefits, the prevalence of vitamin D deficiency remains high worldwide. This was clear among those who died from COVID-19 in 2020/21—most had severe vitamin D deficiency. Herein, the critical mechanisms of how immune cells maintain their robust activities are summarized.
8115 Sep 2023

Breastfeeding and Vitamin D in Preventing Childhood Infections

Human milk is the best food for infants. Breastfeeding has been associated with a reduced risk of viral and bacterial infections. Breast milk contains the perfect amount of nutrients needed to promote infant growth, except for vitamin D. Vitamin D is crucial for calcium metabolism and bone health, and it also has extra-skeletal actions, involving innate and adaptive immunity. As exclusive breastfeeding is a risk factor for vitamin D deficiency, infants should be supplemented with vitamin D at least during the first year. The promotion of breastfeeding and vitamin D supplementation represents an important objective of public health.
37509 Mar 2022

Vitamin D for Treatment of Depression and Anxiety

Major depressive disorder and anxiety disorders are common and disabling conditions that affect millions of people worldwide. Despite being different disorders, symptoms of depression and anxiety frequently overlap in individuals, making them difficult to diagnose and treat adequately. Therefore, compounds capable of exerting beneficial effects against both disorders are of special interest. Noteworthily, vitamin D deficiency has been associated with an increased risk of developing depression and anxiety, and individuals with these psychiatric conditions have low serum levels of this vitamin.
49812 Jul 2022

Vitamin D Supplementation on Fatigue in Multiple Sclerosis

Multiple sclerosis (MS) is an autoimmune and inflammatory chronic disease of the central nervous system that constitutes one of the leading causes of disability among young adults. Multiple sclerosis can produce a variety of symptoms, such as fatigue, blurred vision, optic neuritis, weakness, dizziness, balance disturbances, cognitive decline, and problems with bladder control, as well as an increased risk of depression and anxiety. Fatigue is one of the most common and disabling symptoms and can be described as a subjective lack of physical and/or mental energy that interferes with usual activities.
16304 Jul 2023

Calcium and Vitamin D Supplementation for Periodontal Disease

Periodontal disease is a complex disease that involves an imbalance between the oral microbiota and an individual’s inflammatory response. Moreover, the inflammatory response contributes to further imbalance; if left untreated, periodontal disease may result in tooth loss. Vitamin D is intricately involved in the regulation of calcium–phosphate homeostasis and bone mineral metabolism; considering that periodontal surgery usually includes regenerative therapy, adequate vitamin D and calcium levels are essential.
55519 Jul 2022

Pleiotropic Effects of Vitamin D in Inflammatory-Based Diseases

Vitamin D and Iron on Skeletal Muscle Health

Many nutrients are essential for skeletal muscle health including vitamin D and iron. These nutrients have been well-established to play a role in improving muscular strength, muscle mass, and muscle function in various populations such as youth, athletes, and older adults. Together, muscular strength, muscle mass, and muscle function are important components that make up “skeletal muscle health”. Beyond the role that these nutrients have on skeletal muscle health, emerging literature has reported a link between vitamin D action on pro-inflammatory cytokines and mechanisms behind iron regulation, which may physiologically play a role in skeletal muscle health.
31912 Jul 2022

Vitamin D Scarcity in Arctic and Tropical Peoples

Vitamin D metabolism differs among human populations because the species has adapted to different natural and cultural environments. Two environments are particularly difficult for the production of vitamin D by the skin: the Arctic, where the skin receives little solar UVB over the year; and the Tropics, where the skin is highly melanized and blocks UVB. In both cases, natural selection has favored the survival of those individuals who use vitamin D more efficiently or have some kind of workaround that ensures sufficient uptake of calcium and other essential minerals from food passing through the intestines. Vitamin D scarcity has either cultural or genetic solutions. Cultural solutions include consumption of meat in a raw or boiled state and extended breastfeeding of children. Genetic solutions include higher uptake of calcium from the intestines, higher rate of conversion of vitamin D to its most active form, stronger binding of vitamin D to carrier proteins in the bloodstream, and greater use of alternative metabolic pathways for calcium uptake. Because their bodies use vitamin D more sparingly, indigenous Arctic and Tropical peoples can be misdiagnosed with vitamin D deficiency and wrongly prescribed dietary supplements that may push their vitamin D level over the threshold of toxicity.
82320 Oct 2022

Influence of Vitamin D Levels on Atrial Fibrillation

Atrial fibrillation (AF) is a severe and most common supraventricular arrhythmia in humans, which, if left untreated or treated ineffectively, can lead to ischemic stroke or heart failure. It has been suggested that serum vitamin D (VitD) deficiency may be one of the critical factors influencing the onset of AF, especially in the period after cardiac surgery, such as coronary artery bypass grafting. Several papers have indicated that VitD supplementation reduces the risk of AF, significantly reducing the proportion of patients between the control and study groups in both the pre- and postoperative periods. Factors that increase the risk of AF from VitD deficiency are also further indicated, and these are age, gender, weight, season or comorbidities.
18021 Jul 2023

Multiple Sclerosis in Dental Considerations

Multiple sclerosis is a chronic demyelinating disorder that primarily affects the myeline covering of neurons of the central nervous system.
15212 Jul 2023

The Endothelin System: Morphofunctional Considerations

Acute heart failure (AHF) is a life-threatening condition with high morbidity and mortality. Even though this pathology has been extensively researched, there are still challenges in establishing an accurate and early diagnosis, determining the long- and short-term prognosis and choosing a targeted therapeutic strategy. The use of reliable biomarkers to support clinical judgment has been shown to improve the management of AHF patients. Despite a large pool of interesting candidate biomarkers, endothelin-1 (ET-1) appears to be involved in multiple aspects of AHF pathogenesis that include neurohormonal activation, cardiac remodeling, endothelial dysfunction, inflammation, atherosclerosis and alteration of the renal function.
8327 Jul 2023

Vitamin D in Toxins and Aging-Related Compounds Neutralisation

Vitamin D is a micronutrient that is metabolised into a multifunctional secosteroid compound, calcitriol [1,25(OH)2D], essential for the health and survival of humans. Both 25 dihydroxy vitamin D [25(OH)2D: calcifediol] and its hormonal form, 1,25-dihydroxyvitamin D [1,25(OH)2D: calcitriol] are essential for human physiological functions, including damping down inflammation and the excessive intracellular oxidative stresses. The interaction of 1,25(OH)2D with its intracellular (calcitriol)receptors modulates vitamin D–dependent gene transcription and activation of vitamin D-responsive elements, which triggers multiple second messenger systems. Vitamin D controls systemic inflammation, oxidative stress, and mitochondrial respiratory function. Molecular and cellular actions of calcitriol slow down oxidative stress and inflammation, cell and tissue damage, and the aging process, especially when the circulating 25(OH)D concentration is maintained above 50 ng/mL. Whereas, Vitamin D deficiency impairs mitochondrial functions and enhances oxidative stress and systemic inflammation, increases infection-related complications, premature deaths, and accelerates the aging process.
41220 Jun 2022

Vitamin D on Skeletal Muscle Dysfunction with COPD

Skeletal muscle dysfunction is frequently associated with chronic obstructive pulmonary disease (COPD), which is characterized by a permanent airflow limitation, with a worsening respiratory disorder during disease evolution. COPD is a progressive lung disease, characterized by an irreversible airflow limitation. In COPD, the pathophysiological changes related to the chronic inflammatory state affect oxidant–antioxidant balance, which is one of the main mechanisms accompanying extra-pulmonary comorbidity such as muscle wasting. Muscle impairment is characterized by alterations on muscle fiber architecture, contractile protein integrity, and mitochondrial dysfunction. Vitamin D deficiency affects oxidative stress and mitochondrial function influencing disease course through an effect on muscle function in COPD patients.
33727 Apr 2022

Vitamin D and Urogenital Functions in Postmenopausal Women

Recent years have witnessed the emergence of growing evidence concerning vitamin D's potential role in women's health, specifically in postmenopausal women. This evidence also includes its connection to various genitourinary disorders and symptoms. Numerous clinical studies have observed improvements in vulvovaginal symptoms linked to the genitourinary syndrome of menopause (GSM) with vitamin D supplementation. These studies have reported positive effects on various aspects such as vaginal pH, dryness, sexual functioning, reduced libido, and a decrease in urinary tract infections. Many mechanisms underlying these pharmacological effects have since been proposed. Vitamin D receptors (VDRs) have been identified as a major contributor to its effects. It is now well known that VDRs are expressed in the superficial layers of the urogenital organs. Additionally, vitamin D plays a crucial role in supporting immune function and modulating the body's defense mechanisms. However, the characterization of these effects requires more investigation. Reviewing existing evidence regarding vitamin D's impact on post-menopausal women's vaginal, sexual, and urological health is the purpose of this article. As research in this area continues, there is a potential for vitamin D to support women's urogenital and sexual health during the menopausal transition and postmenopausal periods.
8807 Sep 2023

Improving Clinical Outcomes by Maintaining Vitamin D Sufficiency

Treatment of vitamin D deficiency costs less than 0.01% of one-day hospitalization. Despite cost-benefits, the prevalence of vitamin D deficiency remains high worldwide. This was vivid among those who died from COVID-19—most had vitamin D deficiency. Yet, the lack of direction to use vitamin D as an adjunct therapy from health agencies was astonishing. Data confirmed that keeping an individual’s serum 25(OH)D concentrations above 50 ng/mL (125 nmol/L) (and above 40 ng/mL in the population) reduces risks from community outbreaks and autoimmune disorders. Maintaining such concentrations in 97.5% of people is achievable through daily safe sun exposure (except in countries far from the equator during winter) or taking between 5,000 and 8,000 IU vitamin D supplements daily (average, ~70 to 90 IU/kg body weight). Those with gastrointestinal malabsorption, obesity, or on medications that increase catabolism of vitamin D and a few specific disorders require much higher intake. The text evaluates the doses and administration of vitamin D necessary for better clinical outcomes regarding disease prevention and treatment.
14226 Sep 2023

Vitamin D: Cost-Effectively Overcoming Infections and Chronic Diseases

The prevalence of chronic diseases increases with age, especially in those with co-morbidities. The two most common denominators are the high prevalence of vitamin D deficiency and low concentrations of angiotensin-converting enzyme receptor-2 (ACE2). Whether vitamin D deficiency initiates or aggravates chronic diseases is unclear: the likelihood is both. Hypovitaminosis D negatively affects all body systems, especially the musculoskeletal and immune systems. Many chronic conditions and infections can be minimized using the right dose of vitamin D supplements administered at the right frequency (daily or once weekly) or direct sun exposure to one-third of the skin between 10:30 AM and 1:30 PM, in summer like sunlight, for 20 to 60 minutes depending on the skin tone. It is advisable to wear sunglasses and a brimmed hat to protect one’s eyes and face. Maintaining the population serum 25(OH)D concentration above 40 ng/mL (i.e., sufficiency) ensures a better immune system, minimizing symptomatic diseases and reducing infections and chronic diseases. The best clinical outcome and longevity are expected from maintaining the serum 25-hydroxyvitamin D concentrations between 50 and 80 ng/mL.
56104 Sep 2023 Sunil J. Wimalawansa URL

Serum 25(OH)D and Cognition

Vitamin D, also referred to as serum 25(OH)D, reflects a group of fat-soluble steroids best known for increasing the intestinal absorption of minerals, specifically calcium, magnesium, and phosphate. The impact of serum 25(OH)D on skeletal diseases, such as rickets, has been well documented. There is growing appreciation for the role of vitamin D in cognition and potentially Alzheimer’s disease.
15508 Aug 2022

Lα,25-(OH)2D3 on Osteoclastogenesis

The active form of vitamin D, 1α,25-(OH)2D3, not only promotes intestinal calcium absorption, but also regulates the formation of osteoclasts (OCs) and their capacity for bone mineral dissolution. Gal-3 is a newly discovered bone metabolic regulator involved in the proliferation, differentiation, and apoptosis of various cells.
30229 Mar 2022

Mechanisms of Vitamin D—Controlling Infections and Autoimmunity

Vitamin D—Innate and Acquired Immunity

Vitamin D—Practical Considerations and Clinical Guidance

Vitamin D Serum Concentrations and COVID-19

Vitamin D: Cost-Effectively Overcoming Infections and Chronic Diseases

Vitamin D in Cardiovascular Risk and Disease

Improving Clinical Outcomes by Maintaining Vitamin D Sufficiency

Relationship between Vitamin D and Insulin Resistance

Serum Metabolomes of Gastric Cancers

Gastric cancer (GC) is ranked third in cancer deaths world-wide. It is separated anatomically into either gastric adenocarcinomas (non-cardia GC) or gastro-esophageal-junction adenocarcinomas (cardia GC) and is further classified histologically into either diffuse or intestinal types.
44625 Feb 2021

Serum Bilirubin in Obese Individuals

Bilirubin, the end product of heme metabolism, is a potent endogenous antioxidant with anti-inflammatory, immunomodulatory, antithrombotic, and endocrine properties. Serum bilirubin concentrations depend on the complex interactions between bilirubin production, consumption (depending on oxidative stress and inflammation), metabolism, and elimination. Importantly, numerous studies have shown that serum bilirubin levels are inversely associated with obesity, metabolic syndrome (MetS), type 2 diabetes mellitus (T2DM), and other oxidative-stress-mediated diseases, including atherosclerosis. Moreover, serum bilirubin levels were recently proposed as a potential pre-disease biomarker for developing metabolic syndrome in asymptomatic middle-aged individuals.
54307 Sep 2021

Achieving Optimum Clinical Outcomes with Vitamin D

Serum 25(OH)D and Cognition

Hypervitaminosis D

Hypervitaminosis D is a state of vitamin D toxicity. The normal range for blood concentration is 30.0 to 74.0 nanograms per milliliter (ng/mL).
20314 Oct 2022