Vitamin B-12 is an essential B vitamin that plays a role in digestion, producing DNA and RNA, forming red blood cells and maintaining a healthy nervous system, liver, eyes, hair and skin. It also works with vitamins B-6 and B-9 to control blood levels of an amino acid known as homocysteine. High levels of homocysteine in the blood are linked with heart disease. It has been theorized that vitamin B-12 is beneficial for the heart by reducing heart disease, but research has shown otherwise.
Vitamin B-12 Theory
High levels of homocysteine correlate to risk of heart disease. Your levels of homocysteine are partially determined by genetics, but your diet also influences disease. Homocysteine can damage the lining of your blood vessels, which makes it easier for blood clots to form. This may increase the risk of heart problems. Researchers at the University of California, San Francisco published a study in the "Journal of American Medical Association" in August 2001 that showed projections of how vitamin B-12 and folic acid could reduce heart disease and resulting deaths. They predicted that 0.5 mg of vitamin B-12 and 1 mg of folic acid daily could save 310,000 lives over 10 years by stopping heart disease related deaths
Homocysteine Levels
Studies indicate that people with increased levels of homocysteine are approximately 1.7 times more likely to develop coronary artery disease. Vitamins B-12, B-6 and B-9 greatly influence homocysteine levels. According to the American Heart Association most people can get enough of the necessary B vitamins from the foods they eat. However, people with elevated homocysteine levels, heart disease or a family history of heart disease at a young age may need supplements. You can get vitamin B-12 from dairy products, eggs, fish and shellfish.
Cardiovascular Disease
Heart disease, or cardiovascular disease, is the leading cause of death in the United States. Elevated homocysteine levels has been identified as a risk factor for cardiovascular disease. Despite evidence that B vitamins can lower homocysteine levels, several studies have shown that taking supplements do not actually reduce the risk of cardiovascular disease as assumed, according to the Office of Dietary Supplements of the National Institutes of Health. Due to the failure of studies to prove the effectiveness for vitamin B-12, folic acid and B-6 supplements for heart disease, the American Heart Association states that there is insufficient evidence to support the claim that B vitamins decrease risk of cardiovascular disease.
United Kingdom Study
A study in the United Kingdom effectively proved the falseness of the belief that elevated homocysteine levels are a useful marker to indicate an increased risk of heart events and stroke, according to an article published in "Time" magazine in June 2010. Over the course of seven years, the study observed 12,064 survivors of a heart attack who took daily vitamin B-12 and folic acid. Although the supplements decreased homocysteine levels by 28 percent, the number of heart events and stroke was not different than those of participants taking placebos. It is unknown why lower homocysteine levels do not translate to healthier hearts.
References
- University of California; Folic Acid, Vitamin B12 Show Potential as Heart Disease Treatments; August 2001
- MayoClinic.com: Vitamin B12
- University of Maryland Medical Center: Vitamin B12 (Cobalamin)
- Office of Dietary Supplements: Dietary Supplement Fact Sheet: Vitamin B12
- Time; Study: Folate Acid, B12 Don't Lower Heart-Disease Risks; Alice Park; June 2010
- Harvard School of Public Health: Three of the B Vitamins: Folate, Vitamin B6, and Vitamin B12
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