Vitamin D has been touted as a supplement that can help fight depression. Studies in recent years have supported that theory and until recently, doctors and patients bought into the idea that vitamin D and depression were linked. A new study challenged this belief, however. The meta-analysis found insufficient evidence from previous trials regarding the effectiveness of vitamin D on relieving depression.
Though previous studies linked vitamin D to depression relief, they were not able to make a claim stating that vitamin D deficiency caused clinical depression, or vice versa. The results of randomized trials indicated that while natural sunlight could help relieve depression, taking a vitamin D supplement could also help improve mood and decrease the sadness associated with depression.
A systematic review of clinical trials looked at how vitamin D supplements work for relieving depression. They found that there is not a clear link between vitamin D and depression. The studies in recent years may have been bias and overstated the benefits of taking a vitamin D supplement to treat depression.
Jonathan A. Shaeffer, Ph.D. is an assistant professor at Columbia University Medical Center (CUMC.) He and his colleagues at the Center for Cardiovascular Behavioral Health performed the review, which was recently published in Psychosomatic Medicine. The research was supported by the American Heart Association and the National Institutes of Health.
They used date from randomized trials, comparing the effect that vitamin D had on depression. The researchers looked at seven studies, including roughly 3,200 participants. They found that the trials used limited methods. Only two of the studies included participants who were not clinically depressed. Furthermore, they found that any difference that the studies claimed that the vitamin D made in relieving depression were minimal, at best.
Dr. Shaeffer said that vitamin D may have an effect, but since trials were unclear or had a high risk for bias, more research is necessary for a definitive answer.
The Vitamin D Council cites the inconsistency among the previously published studies on the topic. With so many different conclusions and the fact that it is a relatively new area of study, they cannot support the use of vitamin D for the relief of depression. Tjeir website states, “Vitamin D acts on the areas of your brain that are linked to depression, but exactly how vitamin D works in your brain isn’t yet fully understood.”
What Dr. Shaeffer did conclude, however, is that vitamin D may aid clinically depressed individuals, when taken in combination with an antidepressant drug. He also points out that supplementing with vitamin D may only help depressed patients who also have a vitamin D deficiency. New, more reliable trials are needed to test this theory though.
He said that prescribing vitamin D supplements to depressed patients seems “premature” given the results that he and his team found. There is not sufficient proof that vitamin D is effective for treating depression. The dosage amount and methods also need further study. The hope is that the review of the studies shows their inconsistencies and flaws, while spurring on new studies that may be able to provide clear evidence.
By Tracy Rose