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Vitamin B and folic acid supplements do not prevent cardiovascular diseases

Despite the attractiveness of the hypothesis, folic acid and vitamin B6 and B12 supplements do not lead to a reduction in cardiovascular diseases.

Numerous medical research hypotheses that are appealing on paper turn out to be disappointing in practice. In the 1970s, researchers came up with the theory that a raised concentration of the amino acid homocysteine in the blood caused cardiovascular lesions. This theory was based on the observation of fatal cardiovascular ailments in children with a high level of homocysteine, and a few epidemiological studies showing a statistical link between levels of homocysteine in adults and cardiovascular risk.

Furthermore we know that folic acid, vitamin B6 and vitamin B12 reduce homocysteine. Hence the idea of administering these vitamins to the general population in order to reduce cardiovascular risk.

Several earlier trials evaluating this practice had already produced disappointing results. A new study published in 2008 has perhaps put an end to this avenue of research, so clear are the findings. The administration of folic acid and vitamins B6 and B12 to 5 442 women for over 7 years did indeed lead to a significant drop in homocysteine levels. But this was not linked to a decrease in the number of coronary events, or of cardiovascular accidents, or a reduction in overall mortality or in the mortality rate associated with cardiovascular ailments.

In short, there is no point in reducing the level of homocysteine in the general population or giving vitamin supplements in the hope of preventing cardiovascular diseases.

©Prescrire May 2009

Source: "Vitamines B et acide folique : pas en prévention cardiovasculaire", Rev Prescrire 2009; 29 (306): 291.

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