Shanti Pittampalli, M.D., Steven Lippmann, M.D. 

Affective illness is a devastating cause of suffering, morbidity, disability, and mortality. Even though there are many different interventions available, a significant number of depressed people initially fail to respond well to conventional therapies. Despite much research, the precise mechanism which results in depression remains unknown. There is recent evidence suggesting a role for vitamin D in understanding, evaluating, and treating depression.

Hypovitaminosis D might explain depressive symptoms in some individuals and correction of a deficit might yield improvements in mood. Serotonin levels in brain are in some way related to mood, and vitamin D has influence at regulating serotonin. It also effects dopamine and noradrenaline, which are implicated in causing depressive symptoms. Additionally, inflammation might be associated with affective conditions; cytokines and inflammatory markers are enhanced by deficiencies of vitamin D, via elevated concentrations of calcium and/or reactive oxygen species.

What to do?  What about hypovitaminosis? Not everybody needs their vitamin D levels checked; however, on a clinical basis, consider assaying levels particularly in selected patients with long-term depression when initial therapies were ineffective. In cases of a deficiency, prescribing supplemental vitamin D is a reasonable approach and may be efficacious for affected individuals. There is research substantiating this approach.

What about dosages in vitamin D deficiency? Vitamin D is prescribed orally at a 1,000 IU per day when utilized as a supplement to antidepressant treatments in previously unresponsive cases with evidence of a deficiency. Persons with considerably elevated body mass indices usually require significantly higher doses. Approximately 400-800 IU daily may be sufficient for individuals with seasonal affective disorder. It is important for patients and physicians to be more attentive to dietary and sunlight exposure relationships to vitamin D.  The same applies to the role of vitamin D in mood disorders and/or their pharmacotherapy.

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