B Vitamins and Homocysteine

Homocysteine, an amino acid made in the body, can be harmful if it builds up in large quantities in the body. It is now recognized as an independant risk factor for heart disease because it is thought to damage the lining of the arteries. Many retinal vascular diseases, including macular degeneration, are also associated with homocysteine. Homocysteine has also been linked to diabetes, hypertension, hyperlipidemia, collagen vascular disease, internal carotid disease, and heart disease.

It is important to know that hyperhomocysteinemia is relatively easy to prevent and control. The addition of the proper amounts of the B vitamins, particularly vitamin B6, folic acid, and vitamin B12 to one's diet may decrease homocysteine levels.

Homocysteine in Vegetarians
A recent peer-reviewed study reported that vegetarians have far higher levels of homocysteine than omnivores (meat eaters). Omnivores usually consume recommended levels of the amino acid, methionine. Because methionine is low in plant foods, more vitamin B12 is required by vegetarians. However, vegetarians, even lacto- and lacto-ovo vegetarians (vegetarians who eat eggs and dairy products), have lower blood levels of vitamin B12. The article appeared in the May-June 2000 issue of the Annals of Nutrition & Metabolism.

Here's What You Need to Know:
Below-normal levels of vitamin B12 were found in none of the omnivores, but 26% of the vegetarians and 78% of the vegans (people who eat no animal products) had below-normal levels. Elevated homocysteine was found in 29% of the vegetarians. Even though a vegetarian diet can lower serum cholesterol, the opposite effect on homocysteine could offset any potential benefit.