This study especially hits home for me and not just cause it's a Canadian study :) but because I am heterogyguous for a genetic mutation in the MTHFR gene. This makes me 30-40% less efficient at methylating. The study published in the Canadian Medical Association Journal revealed that people low in vitamin B12 had an increase risk of a fatal heart attack and stroke.
The study focused on the relationship between homocysteine, B-12 and carotid artery plaque.
The study showed that higher blood levels of B vitamins are related to lower concentrations of homocysteine leading to decrease plaquing in the carotid arteries. However, an elevated blood homocysteine level revealed a strong risk factor for heart disease and stroke.
How the Study was Conducted The study examined 421 people with the average age being 66. Vitamin B12, homocysteine levels and degree of plaque in the carotid arteries (via ultrasound) were evaluated.
The Results
Seventy-three patients (17%) had vitamin B12 deficiency with significant elevation of homocysteine. In addition and most important, carotid plaque was significantly larger among the group of patients who had deficiency of vitamin B12 In conclusion, the authors found that low blood vitamin B12 levels are a major cause of elevated homocysteine levels and increased carotid plaque area. Have your Doctor order a blood homocysteine test and a methylmalonic acid (MMA) test(Organic acid test). This is the most specific test for B12 status NOT the serum B-12 blood test. If MMA and homocysteine levels are increased then I would order a MTHFR genetic test to rule out a methylation problem. If only the homocysteine level is elevated, then the person may have a folate deficiency. If both MMA and homocysteine levels are normal, then it is unlikely that there is a B12 deficiency.
Reference
Robertson J, Iemolo F, Stabler SP, Allen RH, Spence JD. Vitamin B12, homocysteine and carotid plaque in the era of folic acid fortification of enriched cereal grain products. CMAJ. 2005 Jun 7;172(12):1569-73.