[Vitamin D supplementation for all older people with COVID-19?]

ABSTRACT

Vitamin D supplementation has been suggested for many diseases and symptoms that are frequent in older people loss of bone mineral density, falls, loss of muscle mass, infections (including COVID-19) and mortality. In observational studies, vitamin D concentration has been associated with many poor outcomes, but in most Randomized Controlled Trials, there is no beneficial effect of vitamin D supplementation on these outcomes, except for bone mineral density. An alternative explanation of the observed association may be 'confounding' older people with poor mobility have lower vitamin D, and irrespective of that also have poor outcomes. The recent COVIT-TRIAL seems to suggest there is benefit of high dose vitamin D supplementation compared to low dose on mortality in older people with COVID-19, but on closer methodological look this conclusion does not hold. Clinical guidelines rightly do not advise vitamin D supplementation for a whole range of diseases, including COVID-19.