The BMJ report states:
Vitamin D and covid-19: enough evidence to recommend supplements
Dear Editor,
There are now close to 30 or so studies demonstrating that having optimal blood levels of 25(OH)-vitamin D (75-150 nmol/L) reduces covid-19 risks: reduced risk of infection; reduced risk of severe disease; reduced risk of dying. Many researchers now regard the evidence as ‘overwhelming’. Despite this, there still will be those who say that we need ‘more research’, but in the meantime, there is little to be lost (vitamin D supplements are inexpensive and have low risk of toxicity) and a huge amount to gain by recommending a decent daily dose of vitamin D3 (say 1-2,000 IU for children and 4-5,000 IU for adults).
Peter J LewisGP (with special interest in integrative medicine1a Cross Street, Brookvale, NSW 2100, Australia)
You can find a link to the report here: The BMJ Report