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 | Homocysteine
By Michael Spilane, MD
Multivitamin tablets are widely available for pennies each, and now there is scientific evidence to show that the darn things are really helpful. In past years, most physicians scoffed at use of multivitamins and felt it was wasted money if the diet was sufficient and well balanced. Now it looks like they were wrong. The evidence is not yet conclusive, but it's pretty strong. It suggests that supplementation of at least some vitamins provides significant protection against heart and vascular disease for older adults, and younger ones as well.
Certain vitamins help rid the body of excess amounts of homocysteine, an essential amino acid normally present in human blood and tissues. Many recent studies demonstrate that high blood levels of homocysteine are strongly associated with increased risk of heart attack, stroke and other complications of arteriosclerosis. It is not yet understood how excess homocysteine interacts to promote vascular disease, but it is known that three vitamins--folic acid, B6 and B12--fuel the metabolic process that normally converts homocysteine to other innocuous body chemicals. Deficiencies of these vitamins lead to excess amounts of body homocysteine and to potential damage to the vascular system.
About thirty percent of Americans have an abnormally high level of homocysteine, and the percentage is probably even higher in the elderly. Dietary deficiencies of folic acid and vitamins B6 and B12 are a major causative factor, but a substantial percentage of the population also harbor a genetically determined abnormality in the metabolic pathway responsible for elimination of homocysteine. Whether caused by a genetic abnormality or a dietary deficiency, it is likely that excess body homocysteine can be avoided or treated by dietary supplements of folic acid and vitamins B6 and B12.
The new knowledge about the risk of excess body homocysteine, and its prevalence among Americans, is yet another indication that the diet of modern civilization is not in tune with our body's needs. For decades we have understood the risks associated with excess consumption of calories, fat and salt, and now we are learning about the risk of homocysteine and the role played by vitamin deficiencies. It is not easy for individuals in a modern society to obtain optimal amounts of certain vitamins from diet alone. We might have to graze rather than cook and eat. We consume far too little of vegetables, fruits and fiber, and cook the vitamins out of the stuff that does contain them.
To combat the risk of elevated homocysteine, older persons should take a standard daily multivitamin tablet containing 400 ug of folic acid, 2 mg of vitamin B6 and 6 ug of vitamin B12. Commonly available multivitamin brands will meet these requirements, but it's a good idea to check the ingredient list. There is no need to pay more than a few cents per tabletexpensive does not mean better. Homocysteine blood levels can be measured, but testing is expensive and unnecessary. Unlike high blood cholesterol, prevention and treatment of elevated blood homocysteine is safe and easy---just take one multivitamin tablet each day. A common multivitamin tablet contains many vitamins other than those necessary to rid the body of excess homocysteine, but they are present in safe amounts and their consumption may avoid other problems. Medical experts estimate that individuals with high levels of homocysteine have a three to four-fold increased risk for complications of arteriosclerosis, contributing to as many as 50,000 deaths in the U.S. each year. While no total proof yet exists that vitamin supplementation is preventative, present evidence is reasonably compelling. And it is hard to find any risk associated with use of a single daily multivitamin tablet.
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