Folic Acid, Vitamin B12 May Reduce Risk of Heart Disease
Taking supplemental vitamin B12 in addition to folic acid may reduce the risk of heart disease more than taking folic acid alone, according to a study in Lancet.1 Individually, vitamin B12 and folic acid each lower levels of homocysteine, a substance in the blood that is an important risk factor for heart disease.
A two-part study was performed to determine the effect of folic acid supplementation on blood levels of homocysteine. In the first part, 30 healthy men were given 100 mcg of folic acid per day for 6 weeks, followed by 200 mcg per day for another 6 weeks and then 400 mcg daily for 12 weeks. The second part of the study involved 23 healthy women who were given 500 mcg per day for four months. Results from the first trial showed that the concentration of homocysteine in the blood decreased progressively, as the amount of supplemental folic acid increased. At a level of 400 mcg of folic acid per day, the average blood level of homocysteine fell by 26%, compared with the pretreatment value. Prior to folic acid supplementation, and during treatment with 100 mcg per day, there was only a weak association between blood levels of vitamin B12 and homocysteine. However, when the larger amounts of folic acid were used, the blood level of vitamin B12 became the main determinant of homocysteine concentrations. Similar results were seen in the second part of the study.
These findings suggest that when the body is saturated with folic acid, taking supplemental vitamin B12, rather than more folic acid, might be the best way to bring down homocysteine levels further. If that is true, then supplementing the average diet with both vitamin B12 and folic acid may be more effective in preventing heart disease than taking folic acid by itself.
Examination of this issue is particularly timely, as the United Kingdom is currently considering mandatory fortification of grains with folic acid. The United States, where folic acid fortification of grains has been in effect since 1998, has seen a reduction in the incidence of neural tube defects, a group of birth defects that results in serious damage to the nervous system.2 While the effect of consuming foods fortified with folic acid and vitamin B12 on homocysteine has yet to be investigated, one study predicted that supplementation with these vitamins would lower homocysteine levels by 24 to 27%.3
The authors of this new report raise the possibility that it may be more desirable to fortify grains with vitamin B12 and folic acid, rather than with folic acid alone. Although such a possibility has not been proven, vitamin B12 is safe and relatively inexpensive. The main food sources of vitamin B12 are animal products; strict vegetarians (vegans) are at increased risk of developing vitamin B12 deficiency.
1. Quinlivan EP, McPartin J, McNulty H, et al. Importance of both folic acid and vitamin B12 in reduction of risk of vascular disease. Lancet 2002;359:227–8.
2. Honein MA, Paulozzi LJ, Mathews TJ, et al. Impact of folic acid fortification of the US food supply on the occurrence of neural tube defects. JAMA 2001;285:2981–6.
3. Tice JA, Ross E, Coxson PG, et al. Cost-effectiveness of vitamin therapy to lower plasma homocysteine levels for the prevention of coronary heart disease. JAMA 2001;286:936–43.
Darin Ingels, ND, MT (ASCP), received his bachelor’s degree from Purdue University and his Doctorate of Naturopathic Medicine from Bastyr University in Kenmore, WA. Dr. Ingels is the author of Garlic and Cholesterol: Everything You Need to Know (Prima, 1999) and Natural Treatments for High Cholesterol (Prima, 2000). He currently is in private practice in Westport, CT, where he specializes in environmental medicine and allergies. Dr. Ingels is a regular contributor to Healthnotes and Healthnotes Newswire.
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