Evidence based non-drug interventions are possible: make population vitamin D replete
Improving our resilience to microbes could be an important non-drug intervention in the fight against Covid19, in addition to ways of preventing transmission, and I agree all public health advice should be evidence based.
One non-drug intervention might be a vitamin D supplementation program to rectify the widespread vitamin D deficiency in the UK which is largely due to a lack of outdoor-living. By now it is well established knowledge that optimal vitamin D is needed for optimal immune function and best defence against microbes, evolution designed humans like that (1). Recently existing evidence was reviewed comprehensively by Linda Benskin (2) showing a causal link between lower than 75 nmol/l blood levels and incidence and severity of Covid19. For comparison, the average D-blood level in England is 45 nmol/l, in Scotland 37 nmol/l (3,4). Several other studies have since also found correlations between vitamin D levels and severe outcomes in Covid19, including in 4.6 million Israelis (5-7). Now, a randomised controlled trial from Spain showed a significant benefit to those receiving vitamin D during hospital admission for Covid19 with more than 90% reduction in ICU admissions and 100% reduction of mortality (8). Although the study had only 76 participants and the authors called for a larger study, there cannot be any doubt, that there is now sufficient evidence for public health departments to engage in implementing a vitamin D repletion program before the next winter rise in severe Covid19 cases.
Unfortunately Public Health advice for all to take a small D-supplement of 10 mcg (400 IU) is insufficient for adults to elevate blood levels to the required optimum, as well as being poorly taken up by some of the Covid19 high risk groups in areas of deprivation.
First, do no harm!
But harm is presently done by tolerating an unacceptably high degree of Vitamin D-deficiency in the UK thereby risking poor outcomes of Covid19.
Competing interests: No competing interests