Vitamin D decreases oxidative stress – meta-analysis Nov 2018

The effect of Vitamin D supplementation on oxidative stress parameters: a systematic review and meta-analysis of clinical trials.

Pharmacol Res. 2018 Nov 14. pii: S1043-6618(18)31210-6. doi: 10.1016/j.phrs.2018.11.011. [Epub ahead of print]

PDF is available free at Sci-Hub   10.1016/j.phrs.2018.11.011

Daily better than weekly, which is better than bi-weekly (ignoring dose size)

Note: 1 trial used only 10 IU - but does not appear to be included in the meta-analysis


Sepidarkish M1, Farsi F2, Akbari-Fakhrabadi M3, Namazi N4, Almasi-Hashiani A1, Maleki A5, Heshmati J6.

• 1 Department of Epidemiology and Reproductive Health, Reproductive Epidemiology Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran.
• 2 Department of Nutrition, School of public Health, Iran University of Medical Sciences, Tehran, Iran; Colorectal research center, Iran University of Medical Sciences, Tehran, Iran.
• 3 Department of Nutrition, School of Public Health, International Campus, Iran University of Medical Sciences, Tehran, Iran.
• 4 Diabetes Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.
• 5 Research Development Center, Arash Women's Hospital, Tehran University of Medical Sciences, Tehran, Iran.
• 6 Department of Nutritional Science, School of Nutritional Science and Food Technology, Kermanshah University of Medical Sciences, Kermanshah, Iran. Javad.Heshmati at gmail.com.

Recent studies have shown that vitamin D supplementation beneficially decreases oxidative stress (OS) parameters; however, there is no consensus on this subject. In this systematic review and meta-analysis we aimed to investigate the effect of vitamin D supplementation on OS parameters. We searched electronic databases including Medline, Embase, Scopus, Web of Science and Cochrane Library up to July 2018 without any language restriction. Trials were reviewed using preferred reporting items for systematic reviews and meta-analyses (PRISMA) and Cochrane handbook. To compare the effects of vitamin D with placebo, standardized mean difference (SMD) with 95% confidence intervals (CI) were pooled using random effects model. Across thirteen clinical trials, we found that vitamin D supplementation increased

• serum levels of total antioxidant capacity (TAC) (SMD: 0.54 mmol/L, 95% CI: 0.29 to 0.79; I2 = 65.4%, P = 0.001) and
• glutathione (GSH) (SMD: 0.33; 95% CI: 0.11 to 0.54, P = 0.003; I2 = 61.2%, P = 0.001).

Besides,

• malondialdehyde (MDA) concentration decreased significantly (SMD: -0.40 mmol/L, 95% CI: -0.60 to -0.21, P < 0.001) following vitamin D supplementation compared to placebo.

However, its effects on nitric oxide (NO) was not significant (0.17, 95% CI: -0.10 to 0.45, I2 = 71.1%, P = 0.21).

Finally, we showed that vitamin D supplementation can improve OS parameters; however, this finding may not be clinically significant. Further large prospective clinical trials are needed to confirm the effect of vitamin D supplement on other OS parameters.