Vitamin D blood levels vary with estimated amount of African Ancestry – Sept 2010

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Blood Vitamin D Levels in Relation to Genetic Estimation of African Ancestry

Cancer Epidemiology, Biomarkers & Prevention September 2010, 19 (9)
1. Lisa B. Signorello1,2,; 2. Scott M. Williams3,; 3. Wei Zheng2,; 4. Jeffrey R. Smith4,; 5. Jirong Long2,; 6. Qiuyin Cai2,; 7. Margaret K. Hargreaves5,; 8. Bruce W. Hollis6 and; 9. William J. Blot1,2

• 1International Epidemiology Institute, Rockville, Maryland;
• 2Division of Epidemiology, Department of Medicine, Vanderbilt Epidemiology Center, Vanderbilt University, and the Vanderbilt-Ingram Cancer Center;
• 3Division of Human Genomics, Department of Molecular Physiology and Biophysics, Vanderbilt University;
• 4Division of Genetic Medicine, Department of Medicine, Vanderbilt University Medical Center;
• 5Department of Internal Medicine, Meharry Medical College, Nashville, Tennessee; and 6Department of Pediatrics, Medical University of South Carolina, Charleston, South Carolina
  • 1. Corresponding Author: Lisa at iei.us

Background: African-Americans generally have lower circulating levels of 25 hydroxyvitamin D [25(OH)D] than Whites, attributed to skin pigmentation and dietary habits. Little is known about the genetic determinants of 25(OH)D levels nor whether the degree of African ancestry associates with circulating 25(OH)D.

Methods: With the use of a panel of 276 ancestry informative genetic markers, we estimated African and European admixture for a sample of 758 African-American and non-Hispanic White Southern Community Cohort Study participants. For African-Americans, cut points of <85%, 85% to 95%, and ?95% defined low, medium, and high African ancestry, respectively. We estimated the association between African ancestry and 25(OH)D and also explored whether vitamin D exposure (sunlight, diet) had varying effects on 25(OH)D levels dependent on ancestry level.

Results: The mean serum 25(OH)D levels among Whites and among African-Americans of low, medium, and high African ancestry were 27.2, 19.5, 18.3, and 16.5 ng/mL, respectively. Serum 25(OH)D was estimated to decrease by 1.0 to 1.1 ng/mL per 10% increase in African ancestry. The effect of high vitamin D exposure from sunlight and diet was 46% lower among African-Americans with high African ancestry than among those with low/medium ancestry.

Conclusions: We found novel evidence that the level of African ancestry may play a role in clinical vitamin D status.

Impact: This is the first study to describe how 25(OH)D levels vary in relation to genetic estimation of African ancestry. Further study is warranted to replicate these findings and uncover the potential pathways involved.

< 85%	85%-95%	> 95%
26 ng	18 ng	16 ng

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76 citations as of Sept 2024

Google Scholar

• Common Variation in Vitamin D Pathway Genes Predicts Circulating 25-Hydroxyvitamin D Levels among African Americans - Dec, 2011 FREE PDF
• Race, Ancestry, and Vitamin D Metabolism: The Multi-Ethnic Study of Atherosclerosis - Dec 2020, FREE PDF
• Genetic and Environmental Factors Are Associated with Serum 25-Hydroxyvitamin D Concentrations in Older African Americans - April 2015 FREE PDF

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VitaminDWiki – Overview Dark Skin and Vitamin D contains

FACT - - People with dark skins have more health problems and higher mortality rate than those with light skins
FACT - - People with dark skins have low levels of vitamin D
FACT - - People with light skins who have low vitamin D have health problems
OBSERVATION - - The health problems of whites with low level of vitamin D are similar to those with dark skins
CONCLUSION - - People with dark skins have more health problems due to low levels of vitamin D
African American Health Disparities are associated with low Vitamin D - Grant Feb 2021
Low Vitamin D increases health problems - independent of skin color

Dark Skin studies: Pregnancy (29 studies),  Genetics (13 studies),  Vitamin D Binding Protein (8 studies),  Vitamin D Receptor (7 studies),  Diabetes (24 studies),   Cardiovascular (18 studies),  Mortality (12 studies), Intervention (16 studies) Click here to see the studies

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VitaminDWiki – Blacks die more often than whites of many diseases (they have less vitamin D) – 2012 contains:

Cancer Facts & Figures for African Americans Cancer.org

• “African Americans have the highest death rate and shortest survival of any racial and ethnic group in the US for most cancers”
• Has a huge number of tables and charts, Note: Vitamin D is not mentioned

Leading Causes of Death as of March 2018

All Ages Death rate	Black	White	Ratio
Heart diseases	217	171	1.27
Cancer	199	170	1.17
Cerebrovascular diseases	51	36	1.4
Diabetes	40	19	2.0

Rates per 100,000    Age adjusted   Non-Hispanic