VITAMIN D DEFICIENCY: A POTENTIAL FACTOR BEHIND DEPRESSION

Abstract

Depression, a leading cause of disability affecting around 264 million people globally has multifactorial causes like psychosocial, biological, genetic and hormonal. Vitamin D, a neuroactive steroid easily crosses blood brain barrier and has widespread receptors in the brain tissue suggesting that vitamin D could have a role in the brain functioning. This paper reviews if vitamin D deficiency is associated with depression and the possible biochemical mechanisms for explaining the same. For this review, scientific studies published till December 2021 were searched on PubMed, Google Scholar and Google using keywords, vitamin D, vitamin D deficiency, depression, mechanisms, association and supplementation. Studies have found that vitamin D is important for expression of neurotransmitters, neuroimmunomodulation and antioxidant production. Neurotrophic hypothesis and monoamine neurotransmission hypothesis explains the biochemical mechanisms behind depression. Many studies found insufficient vitamin D levels being associated with depression and the symptoms improved upon vitamin D supplementation. Thus, it is recommended that serum vitamin D in depression patients should be monitored and normalized if found deficient. Vitamin D supplementation as an adjuvant therapy to standard antidepressants therapy could be more effective to treat depression not responding to standalone vitamin D supplementation. Vitamin D may be used to treat depression especially in patients with poor compliance to antidepressant drugs.