The authors measured levels of serum vitamin B12, homocysteine and carotid plaque in 421 patients referred to vascular disease prevention clinics and found that vitamin B12 deficiency was surprisingly common. They found that, in a subset of 224 patients whose creatinine levels were measured, creatinine levels appeared to be as strong a predictor of homocysteine levels as were vitamin B12 levels.
http://www.cmaj.ca/misc/press/pg1569.pdf .
p. 1569 Vitamin B12, homocysteine and carotid plaque in the era of folic acid fortification of enriched grain products.
-- Julie Robertson et al.
Canadian Medical Association Journal