Re: Covid-19: Public health agencies review whether vitamin D supplements could reduce risk - Most likely they will: not to infection rate but to outcomes
Professor Adrian Martineau is correct when he says that reverse causality might play a role in assessing vitamin D status of people who have become ill with covid-19. In my experience as GP having checked many 25(OH)D levels (1), followed by treatment, those who do have an inflammatory illness have low 25(OH)D levels. There appears to be a “turn over”, vitamin D appears to be “used up”. But treating with D-supplements is still appropriate.
Avoiding vitamin D deficiency within this pandemic isn’t about reducing infection rate, it is about that a healthy 25(OH)D level renders the body to be equipped to battle this infection, it is about preventing the escalation in severity, preventing the need for ventilation and most likely even deaths (2,3). The crucial point is that people must be treated to reach D-sufficiency, that is a serum 25(OH)D of at least 75 nmol/l (30 ng/ml), better even above 100 nmol/l (40 ng/ml) (4-8).
1. Rhein HM. Vitamin D deficiency is widespread in Scotland. BMJ 2008;336June28. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2440863/
3. Davies G, Garami AR, Byers JC. Evidence Supports a Causal Role for Vitamin D Status in COVID-19 Outcomes. June 2020. medRxiv 2020.05.01.20087965; doi: https://doi.org/10.1101/2020.05.01.20087965
4. Vieth R. Best Pract Res Clin Endocrinol Metab. 2011 Aug;25(4):681-91. Why the Minimum Desirable Serum 25-hydroxyvitamin D Level Should Be 75 nmol/L (30 Ng/Ml) https://www.sciencedirect.com/science/article/abs/pii/S1521690X1100073X
5. Holick MF et al. Endocrine Society: Evaluation, Treatment, and Prevention of Vitamin D Deficiency: an Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab 2011, 96 (7):1911 https://academic.oup.com/jcem/article/96/7/1911/2833671
6. Mendes MM, Hart KH, Lanham-New SA, Botelho PB. Suppression of Parathyroid Hormone as a Proxy for Optimal Vitamin D Status: Further Analysis of Two Parallel Studies in Opposite Latitudes. Nutrients. 2020;12(4):E942. Published 2020 Mar 28. https://www.mdpi.com/2072-6643/12/4/942
7. Luxwolda MF, Kuipers RS, Kema IP, van der Veer E, Dijck-Brouwer DA, Muskiet FA. Vitamin D status indicators in indigenous populations in East Africa. Eur J Nutr. 2013;52(3):1115‐1125 https://pubmed.ncbi.nlm.nih.gov/22878781/
Competing interests: No competing interests