Vitamin D from sunlight (the only way to get it) is absorbed through the skin not through the gut. Supplements taken orally aren’t as effectively absorbed. They just run through the digestive tract and get flushed out of the body. There’s a correlation between the almost universal acceptance and overuse of sunblockers and the “epidemic” of Vitamin D deficiency.
Just to clarify: Vitamin D is produced when UV-B rays from the sun turn cholesterol in the skin into the vitamins in question. It can be absorbed orally when taken with food since it’s fat-soluble.
True. But, there’s also some body of evidence that indicates that as we age, our ability to convert UVA radiation into vitamin D diminishes, perhaps significantly.
I eat a very balanced diet with a lot of fish, like tuna and salmon, both excellent sources of vitamin d. I spend a lot of time outside (FL), and usually only put sunscreen on my face and ears (I have darker complexion). And yet, the only supplement my doctor makes me take is Vitamin D because I’m very close to the accepted minimal levels.
Supplements taken orally aren’t as effectively absorbed. They just run through the digestive tract and get flushed out of the body.