Vitamin D has a history of large scale studies pointing both to and away from health benefits, and many western countries already recommend supplementing Vitamin D during winter months. An extensive summary of the evidence for Vitamin D’s various claimed health effects can be found here.

Recently, some evidence has emerged which suggests that Vitamin D may have a protective effect against coronavirus. As Vitamin D supplementation is widely regarded as very safe, and Vitamin D pills are cheap, this has led many people to start taking Vitamin D as a preventative measure. A summary of the case for the protective effect of Vitamin D against Coronavirus is available here. More discussion is available here.

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