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ARS Home » Northeast Area » Boston, Massachusetts » Jean Mayer Human Nutrition Research Center On Aging » Research » Publications at this Location » Publication #203705
Title: VITAMIN B6, B12 AND FOLIC ACID SUPPLEMENTATION AND COGNITIVE FUNCTION: A SYSTEMATIC REVIEW OF RANDOMIZED TRIALS

Author
item BALK, ETHAN - T-NEMC
item RAMAN, GOWRI - T-NEMC
item TATSIONI, ATHINA - T-NEMC
item CHUNG, MEI - T-NEMC
item LAU, JOSEPH - T-NEMC
item Rosenberg, Irwin

Submitted to: Archives of Internal Medicine
Publication Type: Review Article
Publication Acceptance Date: 9/1/2007
Publication Date: 1/11/2007
Citation: Balk, E.M., Raman, G., Tatsioni, A., Chung, M., Lau, J., Rosenberg, I. 2007. Vitamin B6, B12 and folic acid supplementation and cognitive function: a systematic review of randomized trials. Archives of Internal Medicine. 167(1):21-30.

Interpretive Summary: Despite their important role in cognitive function, the value of B vitamin supplementation is unknown. A systematic review of the effect of vitamins B6, B12, and folic acid supplementation on cognitive function was performed. A literature search was conducted in MEDLINE with supplemental articles from reviews and domain experts. We included English language randomized controlled trials of vitamins B6, B12, and/or folic acid supplementation with cognitive function outcomes. Sixteen trials met the criteria; most were of low quality and limited relevance. Approximately 50 different cognitive function tests were assessed. Three trials of vitamin B6 and five of vitamin B12 found no effect overall in a variety of doses, routes of taking vitamin B, and populations. One of three trials of folic acid found a benefit in cognitive function in people with cognitive impairment and low baseline serum folate levels. Four trials of combinations of the B vitamins all concluded the interventions had no effect on cognitive function, though one found that those in the placebo arm had greater improvement in several cognitive tests. The evidence was limited by a small number of studies, small sample size, uniformity in outcomes, and a lack of studies that evaluated symptoms or clinical outcomes. The evidence does not yet provide adequate proof of an effect of B6, B12, or folic acid supplementation, alone or in combination, on cognitive function testing in people with either normal or impaired cognitive function.

Technical Abstract: Despite their important role in cognitive function, the value of B vitamin supplementation is unknown. A systematic review of the effect of vitamins B6, B12, and folic acid supplementation on cognitive function was performed. Literature search conducted in MEDLINE with supplemental articles from reviews and domain experts. We included English language randomized controlled trials of vitamins B6, B12, and/or folic acid supplementation with cognitive function outcomes. Sixteen trials met criteria; most were of low quality and limited applicability. Approximately 50 different cognitive function tests were assessed. Three trials of vitamin B6 and five of vitamin B12 found no effect overall in a variety of doses, routes of administration, and populations. One of three trials of folic acid found a benefit in cognitive function in people with cognitive impairment and low baseline serum folate levels. Four trials of combinations of the B vitamins all concluded the interventions had no effect on cognitive function, though one found that those in the placebo arm had greater improvement in several cognitive tests. The evidence was limited by a sparsity of studies, small sample size, heterogeneity in outcomes, and a lack of studies that evaluated symptoms or clinical outcomes. The evidence does not yet provide adequate evidence of an effect of B6, B12, or folic acid supplementation, alone or in combination, on cognitive function testing in people with either normal or impaired cognitive function.