title: Vitamin B-12: low milk concentrations are related to low serum concentrations in vegetarian women and to methylmalonic aciduria in their infants.
abstract: In a group of 13 strict vegetarian and 6 omnivorous lactating women, relationships were studied among maternal milk and serum vitamin B-12, and milk vitamin B-12 and infant urinary methylmalonic acid (MMA) excretion. Milk vitamin B-12 concentrations were lower in women consuming a strict vegetarian diet compared with an omnivorous diet. Milk vitamin B-12 was inversely related to length of time on a vegetarian diet and positively correlated with maternal serum vitamin B-12 concentrations. Infant urinary MMA excretion was inversely related to milk vitamin B-12 concentrations less than 362 pmol/L. The 1989 recommended dietary allowance for vitamin B-12 of 221 pmol/d for infants is close to the intake below which infant urinary MMA excretion is increased. We conclude that the current RDA for infants provides little margin of safety.
authors.affiliation: Department of Pediatrics, University of Cincinnati Medical Center, OH 45267-0541.
authors.forename: B L
authors.initials: BL
authors.lastname: Specker
authors.forename: A
authors.initials: A
authors.lastname: Black
authors.forename: L
authors.initials: L
authors.lastname: Allen
authors.forename: F
authors.initials: F
authors.lastname: Morrow
mesh_terms: D000328:Adult; D014676:Diet, Vegetarian / Q000009:adverse effects*; D006801:Humans; D007223:Infant; D007774:Lactation; D008297:Male; D008764:Methylmalonic Acid / Q000652:urine*; D008895:Milk, Human / Q000737:chemistry*; D013997:Time Factors; D014805:Vitamin B 12 / Q000032:analysis* / Q000097:blood
chemical_list: D008764:Methylmalonic Acid; D014805:Vitamin B 12