Vitamin B12 deficiency is associated with coronary...[Clin Chem Lab Med. 2009] - PubMed Result
BACKGROUND: The incidence of coronary artery disease (CAD) is increasing at an alarming rate, especially in developing countries, such as India. It is often advocated that a vegetarian lifestyle could reduce the burden of CAD. However, in spite of a majority of Indians being vegetarians, the incidence of CAD is highest in this population. This may be due to deficiency of vitamin B12, a micronutrient, sourced only from animal products.
RESULTS: We found that vitamin B12 levels were significantly lower in coronary artery disease patients than in controls (p<0.0001). Also, vegetarians were found to have significantly lower vitamin B12 concentrations (p=0.0001) and higher incidence of coronary artery disease (p=0.01). Interestingly, elevated homocysteine levels, a hallmark of vitamin B12 deficiency, was not associated with CAD. In contrast, cysteine levels were significantly higher in CAD patients than in controls (p=0.004). CONCLUSIONS: We believe that, when vitamin B12 is deficient, homocysteine is rapidly metabolized via the transsulfuration pathway leading to increased cysteine levels.