Coming from California, all I’ve heard since I got accepted to Penn State is “What are you going to do during the winter?!” I wasn’t all too worried about it (although i probably should be) until I was warned about winter depression. I was told that, due to the lack of sunlight in the winter, i would lack the vitamin D so much that it could cause minor amounts of depression. Particularly because I come from a state where you can’t escape the sun, this prospect of being vitamin D deficient seemed especially bad for my mind and body, so i decided to do a little mythbusting.

So what does the general public think of this myth? Well according to this article on medscape.com (the 3rd most popular link on google), it is very plausible that a lack of vitamin D could cause symptoms of depression. The article pulls direct quotes from psychological researchers whose work was published in an online psychology journal called Psychiatry Research. So far, the google search seems to have yielded pretty credible results.

According to the published work entitled “Associations between vitamin D levels and depressive symptoms in healthy young adult women” that was published early this year, the seasonal changes in vitamin D correlate with the rise depressive symptoms. Though this observational study seems credible, it was only performed on a group of less than 200 women, and on its own isn’t enough to prove the point. after all, correlation does not equal causation!

After a search on Google Scholar, I came across a another article regarding the subject in question. Though it is a little older (2013) than the first source I found it seems to be a  stronger resource than the last. The findings were published in the British Journal of Psychiatry, promising a relative amount of credibility. Not only that, but the amount of subjects they gathered information from was far larger.

But what did their research find? Their conclusion is that “Analyses are consistent with the hypothesis that low vitamin D concentration is associated with depression, and highlight the need for randomised controlled trials of vitamin D for the prevention and treatment of depression to determine whether this association is causal.” In short, like the other study, there was a correlation between seasonal vitamin D levels and symptoms of depression, but no mechanisms were found that are able to be proven as definitely causal.

For all intents and purposes, vitamin D is not a proven causal variable in seasonal depression. Until more experiments take place, like the suggested double blind trial, it is impossible to know for sure whether those vitamin D supplements will keep you happier during the winter. But it does pose a question of ethics. If lack of vitamin D is correlational to symptoms of depression, is it really worth subjecting others to depression with further trials for the sake of proving a point? Since there is no way to be sure, I’ll be playing it safe this winter and taking my vitamins consistently. The risk is too great for me to take, how about you?