title: Low total body bone mineral content and high bone resorption in Korean winter-born versus summer-born newborn infants.
abstract: Seasonal differences in newborn total body bone mineral content (TBBMC) have not been studied, particularly in relation to alterations in vitamin D status in winter. In vitamin D deficiency bone resorption may be high and bone mineralization low. Bone resorption may be assessed by serum cross-linked carboxyterminal telopeptide of type I collagen (ICTP) measures. Because vitamin D supplements throughout pregnancy are uncommon in Korea, we hypothesized that in Korean winter newborns, TBBMC is low and serum ICTP high from high bone resorption and low 25-hydroxyvitamin D (25-OHD) compared with those in summer newborns. Seventy-one Korean term infants were studied prospectively in summer (July through September, n = 37) versus winter (January through March, n = 34); TBBMC was measured before 3 days of age by dual-energy x-ray absorptiometry. Significant seasonal differences were found: winter newborns had 6% lower TBBMC (least squares means +/- SD; 86.7 +/- 7.7 gm vs 93.9 +/- 7.8 gm, p = 0.0002), lower cord serum 25-OHD (10.7 +/- 8 nm vs 30 +/- 15 nm, p = 0.0001) and 1,25-dihydroxyvitamin D, and higher ICTP (96.4 +/- 20.3 microg/L vs 74.8 +/- 24 microg/L, p = 0.0002) and calcium than summer newborns. TBBMC correlated with serum 25-OHD (r = 0.243, p = 0.047) and inversely with ICTP (r = -0.333, p = 0.008). We suggest that in Korea low maternal vitamin D status in winter results in marked reduction in newborn TBBMC.
authors.affiliation: Department of Pediatrics, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: R
authors.initials: R
authors.lastname: Namgung
authors.forename: R C
authors.initials: RC
authors.lastname: Tsang
authors.forename: C
authors.initials: C
authors.lastname: Lee
authors.forename: D G
authors.initials: DG
authors.lastname: Han
authors.forename: M L
authors.initials: ML
authors.lastname: Ho
authors.forename: R I
authors.initials: RI
authors.lastname: Sierra
mesh_terms: D015502:Absorptiometry, Photon; D015519:Bone Density; D001862:Bone Resorption; D002118:Calcium / Q000097:blood*; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D006801:Humans; D006887:Hydroxycholecalciferols / Q000097:blood; D007231:Infant, Newborn / Q000097:blood / Q000502:physiology*; D007723:Korea; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood; D011247:Pregnancy; D011446:Prospective Studies; D012621:Seasons
chemical_list: D006887:Hydroxycholecalciferols; D010281:Parathyroid Hormone; D002118:Calcium