WAGENINGEN, THE NETHERLANDS. There is growing evidence that a high blood level of the amino acid homocysteine is associated with an increased risk for heart attack, stroke, atherosclerosis, Raynaud's phenomenon, and Alzheimer's disease. Folic acid is known to reduce homocysteine levels and is also effective in preventing neural tube defects. However, it has not been clearly established exactly how much folic acid is needed on a daily basis in order to achieve maximum homocysteine reduction.
Researchers at Wageningen University now report that a daily intake of 400 micrograms of folic acid will
reduce homocysteine levels by an average of about 22%. The clinical trial involved 308 Dutch men and
women between the ages of 50 and 75 years. The participants were randomized to receive a placebo or 50,
100, 200, 400, 600 or 800 mcg/day of folic acid for a 12-week period. At the end of the trial homocysteine
concentrations had dropped by about 10% in the groups receiving 50 or 100 mcg/day, by 22% in the 400
mcg/day group, and by about 25% in the groups receiving 600 and 800 mcg/day. The researchers conclude
that about 90% of the maximum homocysteine reduction obtainable through folic acid supplementation can
be achieved by supplementing with 400 micrograms daily.