After reviewing data gathered during a four-year study involving nearly 12,600 participants, researchers have reported a clear link between low levels of vitamin D and depression. A team from UT Southwestern Medical Center and the Cooper Institute found that higher levels of vitamin D were associated with a significantly decreased risk of depression, particularly among individuals with a history of the illness. The opposite proved true as well: low levels of “D” were linked to symptoms of depression, again particularly among those who had a history of depression. The researchers suggested that, based on these findings, doctors may want to screen depressed patients for vitamin D levels and, perhaps, screen patients with low levels of “D” for depression. The study did not investigate whether taking vitamin D supplements relieved depression, nor did the researchers determine whether low levels of “D” contribute to depression or whether depression somehow leads to low levels of “D”. However, they noted that vitamin D may affect neurotransmitters, inflammatory markers and other factors that could explain the link to depression. The study, the largest of its kind, was published in the November 2011 issue of Mayo Clinic Proceedings.
My take? I’m not surprised at these findings. In my new book Spontaneous Happiness, I wrote about the relationship between vitamin D, brain health, and emotional well-being. Receptors for vitamin D occur throughout the brain, and it appears to play an important role in the development and function of that organ, including the activity of neurotransmitters that affect mood. Low levels of vitamin D are associated with seasonal affective disorder and depression, as well as with impaired cognitive function, especially in the elderly. The benefits of vitamin D for both physical and mental health are so numerous and deficiencies are so common that I recommend taking at least 2,000 IU per day.