Healthnotes Newswire—A new study has found that more than 90% of people with low blood levels of either vitamin B12 or folic acid have high levels of homocysteine, an easily modifiable risk factor for heart disease. Moreover, 70% of older people, even many with normal levels of vitamin B12 and folic acid, have high homocysteine.1

Research trials have already found folic acid, vitamin B6 and vitamin B12 to consistently lower homocysteine levels.2,3,4 Several studies have used (and some doctors recommend) 400 to1,000 mcg of folic acid per day, 10 to 50 mg of vitamin B6 per day, and 50 to 300 mcg of vitamin B12 per day. Of these three vitamins, folic acid supplementation lowers homocysteine levels the most for the average person.5,6 Even people with normal blood levels of folic acid can reduce homocysteine by taking folic acid, at least in some situations.7

In the new study, researchers surveyed 200 Argentinean men and women over the age of 65 and found normal blood levels of folic acid and vitamin B12 in the majority of participants. Their average blood homocysteine level was 13.2 micromol/L, significantly higher than the upper limit of normal for both men (11.4 micromol/L) and women (10.4 micromol/L).

The results of the new study, conducted in Argentina, may not be fully applicable to Americans. The Argentinian diet tends to be high in animal proteins and low in green leafy vegetables and other plant foods that are rich in folic acid. However, many Americans do eat a diet similar to that of Argentinians, and one survey among elderly Americans revealed markedly elevated homocysteine levels (greater than 14 micromol/L) in 29.3% of participants. Given the high rate of elevated homocysteine levels across these populations, a B-vitamin supplement seems like a good choice for men and women older than 65.

Several studies have concluded that high levels of homocysteine in the blood are associated with increased risk of heart attacks, strokes, and other cardiovascular diseases. An increase in blood homocysteine from 8 micromol/L (below 9 micromol/L is associated with the lowest risk of developing heart disease) to 13 micromol/L (the average in this study) is associated with a greater than 50% increase in the risk of heart attack or stroke.8

Homocysteine is a by-product of a normal metabolism that can build up in the blood stream of certain individuals. It is thought to somehow directly damage the walls of blood vessels, and that this damage may help start the process of hardening of the arteries. The body uses folic acid, vitamin B6, and vitamin B12 in the metabolic processes necessary to convert homocysteine into other, less toxic substances. Homocysteine can be measured in a standard laboratory test.

The relative importance of homocysteine compared with other risk factors for cardiovascular disease is still being worked out. Most researchers consider it likely, however, that at least some heart attacks and strokes are directly attributable to high homocysteine levels.

—Matt Brignall, N.D.