Relatively small sample and, considering almost half of US citizens are vitamin D deficient, you can't rule out boring correlation (and not causation). EDIT: W

Relatively small sample and, considering almost half of US citizens are vitamin D deficient, you can't rule out boring correlation (and not causation). EDIT: Why does HN have these downvote trolls? I was a bio major and was trained to critically analyze studies just like this. Skepticism is part of science. Why would you downvote my comment?!