[ta988]

I was involved in some vitamin D work. It is really close to what this doctor described about Vitamin C. Or most really ubiquitous natural products really. I've seen all kind of incredible claims and their contrary, and in the end no epidemiologic study or clinical trial showed anything conclusive.

[Aurornis]

Vitamin D deficiency isn’t great, but the health influencer industry really blew this out of proportion. The number of people taking excessive doses because they think more is better is getting scary.

You don’t need a lot of Vitamin D to avoid deficiency. Taking even 5000 IU for an extended period of time can cause Vitamin D excess.

Vitamin D confuses a lot of people because it accumulates over a very long time period. You can take the same dose every day but not approach overdose range for a year or more. It builds up if you’re taking too much, and there is a lot of overlap between “too much” and some of the regimens pushed by health influencers.

[wouldbecouldbe]

vit D is even more random because it's correlated with so much more; being outside; sun exposure; moving etc.

[oldgradstudent]

That's why observational studies consistently show vitamin deficiency correlates with various types ill health, but controlled experiments consistently show that supplementation fails to improve it.

[hombre_fatal]

Apparently it’s because of ethics committees. You can’t do a controlled experiment on people who are vitamin deficient, so iirc modern studies are such comparing people who are not deficient to people who take additional vitamins and find no effect. Which of course doesn’t mean that vitamin supplementation is worthless.

[noobermin]

How about clinical reports/studies? Clearly doctors can give reports whether deficient patients' vitamin D or C levels improve with supplements.

My doctor literally gave me such an oral prescription as my vitamin D levels are low.