Originally Posted by
McBTC
I picked out one of the above studies at random -- second to last -- and, it really goes to show there really are no easy answers here... Did you see the Conclusion?
...multi-factorial... limited evidence to support the proposition that Vitamin D deficiency is performance limiting...
and, what about that callout to the lack of evidence concerning those, "supra-physiological levels," that the authors throw out in the last sentence of their study?
What does this mean...?
Does that mean too much of a good thing may be bad? Some studies say, "yes."
I doubt your choice was random. You have a nice strawman there. I suggest that no one should look to vitamin D as a performance-enhancing supplement. The whole idea is to maintain good health and good bone density. There is a lot of evidence in those articles and studies that appropriate vitamin D blood levels are important for both those things, and that the doctor-prescribed dosages mentioned in comments in this thread are in fact appropriate.
Also note that many doctors are still not up to speed on the difference between D3 and D2, the former being now preferred.