A double-blind, placebo-controlled study published in the Journal of the American College of Nutrition (1992; 11(2):159–163) examined B-vitamin supplementation in geriatric patients diagnosed with depression. Participants received daily supplementation with thiamin, riboflavin, and pyridoxine at doses of 10 mg each, or placebo, in addition to their existing antidepressant medications.
Compared with the placebo group, participants receiving B-vitamin supplementation demonstrated improvements in depression rating scores and measures of cognitive function. The authors reported that the B vitamins appeared to augment the effects of antidepressant therapy in this population.
Notably, serum vitamin B12 levels increased in the treatment group despite the fact that vitamin B12 was not included in the supplementation protocol. No comparable increase in B12 levels was observed in the placebo group. The authors did not establish a mechanism for this finding but noted it as an unexpected observation.
