The health effects of vitamin D supplementation: evidence from human studies

UV causes skin cancer - but the majority of them (10:1) are basal cell and squamous cell carcinomas. These have a 99-100% 5-year survival. While UV exposure can increase the risk of melanomas, it makes you less likely to die from them [1]. The UVA-mediated release of nitric oxide from the skin improves your cardiovascular health and you are far more likely to die of CVD than skin cancers, especially if you screen for them. Early stage melanomas have a 99.6% 5-year survival. [1] https://academic.oup.com/jnci/article/97/3/195/2544082 Also note there is very limited evidence for the health benefits of vitamin D supplementation, especially if you're anywhere close to a normal level. [2] https://www.nature.com/articles/s41574-021-00593-z

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 It is out-of-date.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.

Good thing I also mentioned doctors, who are, of course, applying the concluded result of research. But maybe you are talking about another "medical context". I threw your "vitamin D supplementation proved beneficial" into Google and this Nature review article on vitamin D supplementation was the first result: * https://www.nature.com/articles/s41574-021-00593-z Here is some additional reading you may find interesting: * https://en.wikipedia.org/wiki/Ad_hominem

There is very little evidence for vitamin D supplementation unless tests show you are severely deficient. If you’re replete they do nothing. Getting outside is significantly more beneficial. Unless a test shows you’re on the rickets train it’s not going to do much or anything. Basically the same as any other vitamin, if you’re deficient correct the deficiency. If you’re not don’t waste your time. [edit] also note that in the sun UVB rays cause production of vitamin D while UVA rays cause the release of nitric oxide which lowers blood pressure and improves cardiovascular health. That’s likely a real benefit of going outside separate from the D pathway. [1] https://www.nature.com/articles/s41574-021-00593-z

What's interesting with Vitamin D supplementation is there doesn't appear to be any strong clinical evidence for its effectiveness unless you're severely deficient and on the road to rickets. So long as your serum 25OHD concentration is >50nmol/L according to this meta analysis, there's no clear effects. [1] > In conclusion, supplementation of vitamin D-replete individuals does not generate overall health benefits; however, correction of severe vitamin D deficiency remains essential. Probably would be a lot better off going outside and synthesizing your own. Spending time in nature and in the sun does a lot of other useful things - for instance UV exposure induces nitric oxide synthesis too, which lowers blood pressure. [2] [1] https://www.nature.com/articles/s41574-021-00593-z [2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5593895/