A 2010 report published in The American Journal of Clinical Nutrition showed a decreased risk for depression when greater amounts of B6 and B12 were consumed (1).
Over 3500 participants were evaluated over 12 years as part of the Chicago Health and Aging Project. Higher intakes of Vitamins B6 and B12, from both food and supplements, were associated with less depressive symptoms.
B12 (also known a cobalamin) is required for energy, heart and mood health, and the integrity and function of the nervous system. B-12 is a unique B vitamin, in that it requires a strong digestive system to absorb. This results in a high percentage of deficiencies. B-12 deficiencies are due to many factors, including an epidemic of weak digestion, which is illustrated by a growing inability to digest wheat, dairy and fatty foods.
Other factors include the use of antacids, most medications, vegetarianism, stress, and aging.
The richest food sources of B12 are meat, dairy and eggs, as plants are generally low in B-12. Vegetable sources include kelp, brewers yeast, and fermented foods such a tempeh, miso and sauerkraut.
Vegetarians, folks on any medication, and the elderly are at risk for a B-12 deficiency, and should consider B12 supplementation. One study showed that 80% of vegetarians were B-12 deficient.
B-6 (also known as pyridoxine) is important in the breakdown of fats, carbohydrates, and proteins. It also supports red blood cells, nerves, skin, and hormone production. It is abundant in many fresh foods but not in processed, canned or frozen foods, so aim to eat a diet rich in whole foods.