Posted 13May2020 Dr. John Campbell,Quite Compelling Evidence:Does Vitamin D Protect Against COVID-19? https://www.medscape.com/viewarticle/930152?src=soc_tw_share
So the evidence is becoming quite compelling.
JoAnn E. Manson, Professor of medicine at Harvard Medical School Division of Preventive Medicine at Brigham and Women’s Hospital, in Boston, Massachusetts.
Already known about Vit D status Bone health, Cardiometabolic health. But it may be even more important now than ever Risk of developing COVID-19 infection and to the severity of the disease. Innate immunity and boosts immune function against viral diseases
Immune-modulating effect
Can lower inflammation
This may be relevant to the respiratory response with COVID – 19 and the cytokine storm.
Laboratory (cell-culture) studies Evidence that patients with respiratory infections tend to have lower blood levels of 25-hydroxy-vitamin D
Some evidence from COVID-19 patients as well.
Eightfold higher risk of having severe COVID illness among those who entered with vitamin D deficiency compared with those who had sufficient vitamin D levels
Supplementation was associated with a significant reduction in respiratory tract infections
12% to 70% reduction of respiratory infection with vitamin D supplementation
So the evidence is becoming quite compelling
Encourage our patients to be outdoors and physically active, while maintaining social distancing

Diet
food labels
fortified dairy products
fortified cereals
fatty fish
sun dried mushrooms
Quite reasonable to consider a vitamin D supplement RDA, 600-800 IU/dailyBut during this period, a multivitamin or supplement containing 1000-2000 IU/daily of vitamin D would be reasonable

Planning a randomized clinical trial, moderate to high doses In the meantime,
it’s important to encourage measures that will, on a population-wide basis, reduce the risk for vitamin D deficiency
Dr JoAnn Manson is a professor of medicine at Harvard Medical School; and chief of the Division of Preventive Medicine at Brigham and Women’s Hospital, in Boston, Massachusetts.