Previous studies have suggested that B vitamins might help protect against depression, but these were mostly snapshots at a single point in time. Now a new study connects B-vitamin intake among 3,503 seniors, initially free of depression, over a span of 12 years: For every 10-milligram increase in daily vitamin B6, risk of developing depression declined by 2%. The same was true for every additional 10 micrograms of vitamin B12.Reporting their findings in the American Journal of Clinical Nutrition, Kimberly A. Skarupski, PhD, of Rush University, and colleagues commented, In the assessment and treatment of depressive symptoms in older adults, clinicians and other healthcare professionals should be mindful of the patients nutritional status in general, and whether there are vitamin insufficiencies in these nutrients before treatment.They looked for effects of such insufficiencies on depression among participants in the Chicago Health and Aging Project, average age 73.5. Onethird were widowed, 59% were female and 59% were African- American.Both dietary and supplement intake of B6 and B12 were linked to reduced risk of depression. The association with B12 from dietary sources alone was marginal, however. Dr. Skarupski and colleagues said this likely represents the poor bioavailability and absorption of vitamin B12 from food sources, especially in older age. Over age 60, some people become less able to absorb B12 from food.Folate, another B vitamin previously linked to lower depression incidence, was not associated with reduced risk. Researchers speculated this may be because folate deficiency is rare in the US, thanks to fortified grains and cereals.
| Dietary sources of vitamin B6 include fortified cereal, potatoes, garbanzo beans, bananas, meat and chicken, trout and salmon, and avocado. Men over 50 are advised to get 1.7 milligrams per day, while women should get 1.5 milligrams, about the amount in three bananas.Dietary sources of vitamin B12 include liver, clams, fortified breakfast cereals, beef, salmon and trout, yogurt and milk. Men and women both should aim for 2.4 micrograms per day, about the amount in 3 oz. of top sirloin. |
Dr. Skarupski and colleagues cautioned that the findings dont show cause and effect; adequate B vitamin intake might, for example, simply be a sign of an overall healthy diet. But the researchers said the study bolsters the case that low B vitamin intake might be a risk factor for depression.In an accompanying editorial, Seren Haf Roberts, PhD, of Bangor University in Wales, and colleagues warned that evidence for such a link is still not clear-cut. Nonetheless, the editorial said the study has made an important contribution to a long-running fascination with the associations between B vitamins and depression.TO LEARN MORE: American Journal of Clinical Nutrition, August 2010; abstract at www.ajcn.org/cgi/content/ abstract/92/2/330