I’ve often wondered if the higher vitamin D we get from the sun or even tanning beds outweighs the risks from melanoma. Low vitamin D is a big risk factor in the modern world.
https://ajcn.nutrition.org/article/S0002-9165(22)03753-4/
https://ar.iiarjournals.org/content/38/2/1111
> Therefore, we rebut these conclusions by addressing the incomplete analysis of the adverse health effects of UV and sunbed exposure (what is ‘safe’?) and the censored representation of beneficial effects, not only but especially from vitamin D production. The stance taken by both agencies is not sufficiently supported by the data and in particular, current scientific knowledge does not support the conclusion sunbed use increases melanoma risk.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3897598/
>Thus when the skin is exposed to sunlight it can only convert approximately 15% of 7-dehydrocholesterol to previtamin D3 (Fig. 18).32 Any further exposure will result in a photoequilibrium whereby previtamin D3 is converted into lumisterol3 and tachysterol3 as well as revert back to 7-dehydrocholesterol (Fig. 17). In addition when vitamin D3 is made from previtamin D3 in the skin if it is exposed to solar UVB radiation it will absorb UVB radiation and be converted into several suprasterols and 5,6-trans-vitamin D3 (Figs. 17 and and19).19). In addition previtamin D3 can also be converted to several toxisterols (Fig. 20).33-36 Therefore no matter how much sun a human is exposed to vitamin D intoxication will not occur because any excess previtamin D3 and vitamin D3 is photodegraded into products that have no calcemic activity.31,32
I am a case in point: I am frequently outdoors in all seasons, well beyond the point where I have to be careful to avoid sunburn, yet I have a significant all-seasons vitamin D deficiency. The conclusion of the abstract to the article you link to says "a three-part strategy of increasing food fortification programs with vitamin D, sensible sun exposure recommendations and encouraging ingestion of a vitamin D supplement when needed should be implemented to prevent global vitamin D deficiency and its negative health consequences" [my emphasis.]
> In spring and summer, 25 percent of the body (the hands, face, neck and arms) is exposed to the sun, and in these seasons, about 8 to 10 minutes of sun exposure at noon produces the recommended amount of vitamin D.
[1] https://www.uclahealth.org/news/article/ask-the-doctors-roun...
I assume that this is a personal thing, something about my specific metabolism or skin or whatever that doesn't produce vitamin D particularly well. I have no idea if the supplement actually improves my health outcome -- I was generally healthy both before and after adding supplements.
My advice, such as it is: don't take any supplement without a doctor telling you it's needed. But if a doctor says it's necessary, yeah, do that.
Diphenhydramine: https://pubmed.ncbi.nlm.nih.gov/27779705/