Folic Acid (Vitamin B9): Folic acid or folate is a vitamin of B complex group. It is deficient in depression patients. Studies from Harvard University found that when antidepressant drugs don’t work effectively when there is deficiency of folic acid.

Enhancement of the antidepressant action of fluoxetine by folic acid; a randomized, placebo controlled trial. J Affect Disord. 2000 Nov; 60(2):121-30.

Vitamin B6 or Pyridoxine: Vitamin B6 plays important role in the synthesis of neurotransmitters serotonin and nor epinephrine and both of these play important role in depression and other emotional problems. People don’t lack this vitamin commonly however the use of contraceptive pills, hormone replacement therapy and ant tubercular drugs can cause its deficiency.

Vitamin C: Vitamin C indirectly catalyzes the reactions that are related with production of serotonin. Its use is also helpful for countering the dry mouth like side effects of some antidepressant drugs.

Vitamin D: Vitamin D, particularly Vit. D3 is good for enhancing mood. Vit. D is considered as a prohormone and various benefits are attributed to it other than calcium metabolism. Its supplementation is found to uplift mood even in healthy subjects during winter season.

Vitamin D3 enhances mood in healthy subjects during winter. Psychopharmacology (Berl). 1998 Feb; 135(4):319-23