Metabolic vitamin B12 status on a mostly raw vegan diet with follow-up using tablets, nutritional yeast, or probiotic...

Pure vegetarian diets might cause cobalamin deficiency due to lack of dietary intake. It was hypothesized that a population following a vegan diet consuming mostly raw fruits and vegetables, carrot juice, and dehydrated barley grass juice would be able to avoid vitamin B12 deficiency naturally.

Subjects were recruited at a health ministers' reunion based on adherence to the Hallelujah diet for at least 2 years. Serum cobalamin and urinary methylmalonic acid (MMA) assays were performed. Follow-up with sublingual tablets, nutritional yeast, or probiotic supplements was carried out on subjects with abnormal MMA results.

49 subjects were tested. Most subjects (10th to 90th percentile) had followed this diet 23-49 months. 6 subjects had serum B12 concentrations <147 pmol/l (200 pg/ml). 37 subjects (76%) had serum B12 concentrations <221 pmol/l (300 pg/ml). 23 subjects (47%) had abnormal urinary MMA concentrations above or equal to 4.0 microg/mg creatinine. Sublingual cyanocobalamin and nutritional yeast, but not probiotic supplements, significantly reduced group mean MMA concentrations (tablet p < 0.01; yeast p < 0.05, probiotic > 0.20).

The urinary MMA assay is effective for identifying early metabolic cobalamin deficiency. People following the Hallelujah diet and other raw-food vegetarian diets should regularly monitor their urinary MMA levels, consume a sublingual cobalamin supplement, or consume cobalamin in their food.