title: Vitamin B12 deficiency is associated with coronary artery disease in an Indian population.
abstract: 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.
  
  
  METHODS
  Herein, we assessed the effect of vitamin B12 with respect to CAD in 816 individuals (368 CAD patients and 448 controls) recruited from a tertiary care center in New Delhi, India.
  
  
  RESULTS
  We found that vitamin B12 levels were significantly lower in CAD 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 CAD (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.
authors.affiliation: Institute of Genomics and Integrative Biology, Delhi, India.
authors.forename: Jitender
authors.initials: J
authors.lastname: Kumar
authors.forename: Gaurav
authors.initials: G
authors.lastname: Garg
authors.forename: Elayanambi
authors.initials: E
authors.lastname: Sundaramoorthy
authors.forename: P Veerendra
authors.initials: PV
authors.lastname: Prasad
authors.forename: Ganesan
authors.initials: G
authors.lastname: Karthikeyan
authors.forename: Lakshmy
authors.initials: L
authors.lastname: Ramakrishnan
authors.forename: Saurabh
authors.initials: S
authors.lastname: Ghosh
authors.forename: Shantanu
authors.initials: S
authors.lastname: Sengupta
mesh_terms: D003324:Coronary Artery Disease / Q000097:blood / Q000150:complications* / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D014806:Vitamin B 12 Deficiency / Q000097:blood / Q000150:complications* / Q000453:epidemiology*