Taking a supplement with both folic acid and vitamin B12 lowers homocysteine levels more dramatically than taking folic acid alone, according to a report in the American Journal of Clinical Nutrition.

Homocysteine is an amino acid that has been associated with a greater risk of heart disease. Previous studies have indicated that folic acid can lower homocysteine levels.

Although it has not been proven that lowering homocysteine level can prevent heart problems, the American Heart Association issued an advisory this week suggesting that those with a history of heart disease make sure that they consume the recommended daily allowance (RDA) of vitamin B6, vitamin B12, and folic acid.

And because adequate folic acid intake during pregnancy can reduce the risk of certain birth defects, namely neural tube defects, the US Food and Drug Administration ruled that all grain and grain products should be fortified with folic acid as of January 1, 1998.

In the new study of 150 women, homocysteine levels dropped by 11% in those taking 400 micrograms (mcg) of folic acid alone, 15% in those taking folic acid and 6 mcg of vitamin B12, and 18% in those taking folic acid and 400 mcg of B12.

"These results suggest that the addition of vitamin B12 to folic acid supplements or enriched foods maximizes the reduction of homocysteine and may thus increase the benefits of the proposed measures in the prevention of vascular disease and neural tube defects," concluded Klaus Pietrzik and colleagues at the Institute of Nutritional Science at the University of Bonn in Germany.

Sources

American Journal of Clinical Nutrition 1998;68:1104-1110.