title: Bone mineral content is not reduced despite low vitamin D status in breast milk-fed infants versus cow's milk based formula-fed infants.
abstract: The effect of low or borderline vitamin D status on bone mineralization of exclusively breast milk-fed infants has not been studied. The low vitamin D status of Korean breast milk-fed infants may theoretically have adverse effects on bone mineralization. Assuming that bone mineral content (BMC) relates in part to vitamin D status, we hypothesized that serum 25-hydroxyvitamin D (25-OHD) concentration and BMC would be low, and serum osteocalcin concentration high, reflecting active bone turnover, in breast milk- versus formula-fed infants born in the winter. Eighteen breast milk- and 17 formula-fed infants were recruited at ages 2 to 5 months. The BMC of the lumbar1-4 spine region was measured by using dual energy x-ray absorptiometry. The BMC and serum osteocalcin levels were similar for both groups. The serum 25-OHD level was significantly lower in breast milk- than formula-fed infants; 44% of the breast milk group versus 6% of the formula group had serum 25-OHD levels less than 28 nmol/L (11 ng/ml), the lower limit of normal. The BMC did not correlate with the serum 25-OHD level. Thus BMC and serum osteocalcin levels in 2- to 5-month-old infants were not different by type of feeding, despite low vitamin D status in breast milk-fed infants. We speculate that adequate mineral absorption occurs during this period from a predominantly (vitamin D independent) passive transport mechanism.
authors.affiliation: Department of Pediatrics, Inje University College of Medicine, Sanggye Paik Hospital, Seoul, Korea.
authors.forename: M J
authors.initials: MJ
authors.lastname: Park
authors.forename: R
authors.initials: R
authors.lastname: Namgung
authors.forename: D H
authors.initials: DH
authors.lastname: Kim
authors.forename: R C
authors.initials: RC
authors.lastname: Tsang
mesh_terms: D015502:Absorptiometry, Photon; D000818:Animals; D015519:Bone Density; D016723:Bone Remodeling / Q000502:physiology; D001903:Bottle Feeding; D001942:Breast Feeding; D002417:Cattle; D005260:Female; D006801:Humans; D007223:Infant; D007225:Infant Food; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D008297:Male; D008892:Milk; D008895:Milk, Human; D015675:Osteocalcin / Q000097:blood; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D015675:Osteocalcin; D014807:Vitamin D; C104450:25-hydroxyvitamin D