Some observational studies have linked depression to low levels of vitamin D. There have been some small, controlled trials that have tested whether or not vitamin D supplements can prevent or treat depression. So far those studies have generated conflicting results.
Recently, in a much larger study, researchers have analyzed data from the Women’s Health Initiative Calcium and Vitamin D Trial in 36,282 women aged 50 to 80 who were randomized to 400 IU vitamin D (with 1000 mg calcium) or to placebo. After 2 years it was determined that the vitamin D supplements had absolutely no effect on risk for, or against, depressive symptoms above threshold or on antidepressant use either in the entire group or in the subgroup.
Although this very large study did not show any benefit from the use of vitamin D for the treatment or prevention of depression, lack of vitamin D in those who suffer from depression could be related to lifestyle and poor diet. Another point that was made is that an increase in dosage could have more of an effect. Vitamin D is still very important and with proper nutrition can help improve people’s lives both physically and mentally.
Bertone-Johnson ER et al. Vitamin D supplementation and depression in the Women’s Health Initiative Calcium and Vitamin D Trial. Am J Epidemiol 2012 Jul 1; 176:1. Published in Journal Watch Psychiatry August 30, 2012