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This paper is from 2013. It is out-of-date. More recent large scale studies of Vitamin D supplementation show no benefit, except in cases of substantial deficiency.

https://www.nature.com/articles/s41574-021-00593-z

Sunlight, however, does show benefits. This suggests that Vitamin D is just a side effect of sunlight exposure, and does not by itself do any good.

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Interesting about "supplementation of vitamin D-replete individuals does not provide demonstrable health benefits". The OP article does clearly call out that the benefits of vitamin D are in cases of _vitamin D deficiency_. It goes on to state that there is a "worldwide vitamin D deficiency pandemic" and mentions that 32% of children and adults have a circulating concentration of 25(OH)D < 20 ng/mL (i.e. vitamin D deficient).

So I think the broader point of the article was that many of us are vitamin D deficient, and those of us that are, have increased health risk, and that's why we need to supplement our vitamin D.

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