Vitamin D and Pandemics Re: Malnutrition: the silent pandemic
Vitamin D and Pandemics
Henry Mark and colleagues are rightly concerned that there is a silent pandemic of malnutrition during this Covid-19 pandemic, especially because adequate intakes of energy, macronutrients, and micronutrients are critical for immune functioning. They quote Naja and Hamadeh, who list Vitamins A, C, E, B6, B12, Zinc and iron as important. Unfortunately this list does not include Vitamin D.
In contrast, Dr David Grimes emphasises in his Blog that 19 world-wide studies now demonstrate that low blood levels of Vitamin D are associated with severe or fatal Covid-19.
Grimes writes that the emergence of cytogenetics led to the identification of the 1,25(OH)D–VDR dimer to activate what is now a surprisingly large number of genes (in excess of 1,000). Some of these generate even more VDR molecules, a positive feedback mechanism. But 1,25(OH)D can only be used once as after use it is deactivated into 24,25(OH)D. This vital metabolic control prevents a damaging excess of 1,25(OH)D. However it means that a constant supply of 25(OH)D is essential during the escalation of defensive immunity in response to infection, so as to replace the 1,25(OH)D that has been deactivated. The need of vitamin D in defensive immunity is much greater than for the control of ionised calcium, a fact that is seriously under-appreciated.
The latest International studies indicate that a blood level of more than 30ng/ml (75nmol/L) is a level that indicates protection against serious or fatal Covid-19 infection. A target level of 40ng/ml (100nmol/L) would appear to be appropriate, and to achieve this vitamin D in a daily supplement of 4,000 units is effective, perfectly safe, and costs about £12 per year.
1 Mark HE, da Costa GD, Pagliari C, Ungar SA. Malnutrition: the silent pandemic. BMJ 2020;2020;371:m45931 doi: https://doi.org/10.1136/bmj.m4593 (Published 01 December 2020)
2 Naja F, Hamadeh R. Nutrition amid the COVID-19 pandemic: a multi-level framework for action. European Journal of Clinical Nutrition 2020;74:1117-1121.
Competing interests: No competing interests