Risk of persistent cobalamin deficiency in adolescents fed a macrobiotic diet in early life

Background: Cobalamin deficiency has been described in children consuming m acrobiotic diets. Objective: We investigated whether moderate consumption of animal products is sufficient for achieving normal cobalamin function in 73 adolescents who had received a macrobiotic diet until 6 y of age and had then switched to a lactovegetarian, lactoovovegetarian, or omnivorous diet (macrobiotic adol escents). Design: Hematologic indexes and serum concentrations of methylmalonic acid (MMA), total homocysteine (tHcy), and folate were measured. Current consump tion frequency of animal products and cobalamin intake from dairy products were assessed by questionnaire. Data from 94 age-matched adolescents who re ceived an omnivorous diet from birth were used as a reference. Results: Serum cobalamin concentrations were significantly lower and concen trations of MMA and folate and mean corpuscular volume (MCV) were significa ntly higher in macrobiotic adolescents than in control adolescents: of macr obiotic adolescents, 21% had abnormal MMA concentrations (>0.41 mu mol/L), 37% had abnormal cobalamin concentrations (<218 pmol/L), 10% had abnormal t Hcy concentrations (>12.8 mu mol/L), and 15% had abnormal MCV (>89 fL). In macrobiotic adolescents, dairy products (200 g milk or yogurt and 22 g chee se/d) supplied on average 0.95 mu g cobalamin/d; additionally, these adoles cents consumed fish, meat, or chicken 2-3 times/wk. In girls, meat consumpt ion contributed more to cobalamin status than the consumption of dairy prod ucts, whereas in boys these food groups were equally important. Conclusions: A substantial number of the formerly strict macrobiotic adoles cents still had impaired cobalamin function. Thus, moderate consumption of animal products is not sufficient for restoring normal cobalamin status in subjects with inadequate cobalamin intake during the early years of life.