Vitamin D Improves Mood

A recent literature review on vitamin D and mood written by Alan Gaby, MD, starts out with this sentence:

One investigator (John Denver) reported anecdotally that sunshine on his shoulder made him happy. A recent study adds scientific support to that observation and suggests that the mood-elevating effect of sunshine is mediated by vitamin D.


This opening line made me laugh and so I have decided to paraphrase Dr Gaby’s review here. You can go to this YouTube link and have John Denver play his song in the background while you read this:

Gaby starts out looking at a December 2008 study that reported on a double blind study in which researchers randomly gave vitamin D or placebo to 441 overweight Norwegians. The lower their starting vitamin D levels, the more likely they were to be depressed. Subjects took 20,000 IU, 40,000 IU, or a placebo once a week for a year. About ¾ of the participants completed the study and of those that did, the more vitamin D they took, the better they felt. Depression as measured by a standard questionnaire decreased by 33% in the group receiving 40,000 IU per week, by 20% in the group receiving 20,000 IU per week, and by 5% in the placebo group, though the decrease in the last group was not statistically significant.

This isn’t the first study to report that vitamin D makes people happier. A double-blind study from Australia published way back in 1998 showed that taking as little as 400 IU per day for five days produced a measurable improvement in mood. I’ve mentioned this study in earlier newsletters, as these patients were all suffering from Seasonal Affective Disorder (SAD). Another study along the same theme was published a year later. It reported on 15 patients with SAD who were randomly chosen to get either 100,000 IU of vitamin D-2 (no longer our first choice for the most bioavailable form of vitamin D, by the way) or two hours of phototherapy daily for a month. The patients who received the vitamin D had their depression score improve 43% while the phototherapy group showed no improvement.