title: Vitamin D and parathormone levels of late-preterm formula fed infants during the first year of life.
abstract: OBJECTIVE
  Preterm infants are at risk for low vitamin D but documentation on late-preterm infants is sparse. This prospective study monitored longitudinally vitamin D and parathormone (PTH) levels in late-preterm formula fed infants during the first year of life, taking into consideration in utero and postnatal growth, and season and diet.
  
  
  METHODS
  The study population comprised 128 infants of gestational age (GA) 32-36 weeks, of which 102 were appropriate (AGA) and the remaining 26 were small for GA (SGA). Serum levels of vitamin D (25(OH)D), PTH calcium, phosphate (P) and alkaline phosphate were estimated at 2 and 6 weeks, and at 3, 6, 9 and 12 months of age.
  
  
  RESULTS
  The 25(OH)D levels were relatively low at 2 and 6 weeks in both AGA and SGA infants (21±11, 20±7 ng/ml and 25±16, 23±8 ng/ml, respectively), but increased at 6 months (45±14, 47±10 ng/ml) and remained stable thereafter. SGA infants had lower 25(OH)D levels at 9 and 12 months (AGA 45±14, 47±18 ng/ml vs SGA 38±13, 37±13 ng/ml, P<0.05). Deficiency of 25(OH)D (<20 ng/ml) was found in 18.5% of measurements in 92 (72%) infants, and its insufficiency (20-32 ng/ml) was found in 29.2% of measurements in 99 (77.3%) infants. Most measurements with vitamin D <32 ng/ml were observed at the first three study points, where PTH showed an inverse association with 25(OH)D, reaching a plateau thereafter.
  
  
  CONCLUSIONS
  Late-preterm, formula fed infants may have suboptimal vitamin D levels and elevated PTH, especially, during the first 3 months. Those born SGA may have lower vitamin D levels up to the end of the first year of life.
authors: Neonatal Intensive Care Unit, University Hospital of Ioannina, Ioannina, Greece. vgiapros@cc.uoi.gr
authors: V I
authors: VI
authors: Giapros
authors: V
authors: V
authors: Schiza
authors: A S
authors: AS
authors: Challa
authors: V K
authors: VK
authors: Cholevas
authors: P D
authors: PD
authors: Theocharis
authors: G
authors: G
authors: Kolios
authors: C
authors: C
authors: Pantou
authors: S K
authors: SK
authors: Andronikou
mesh_terms: D001903:Bottle Feeding; D004032:Diet; D005260:Female; D005865:Gestational Age; D006801:Humans; D007223:Infant; D041943:Infant Formula / Q000494:pharmacology; D007227:Infant Nutritional Physiological Phenomena; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000097:blood / Q000453:epidemiology; D007234:Infant, Premature / Q000097:blood*; D007236:Infant, Small for Gestational Age / Q000097:blood*; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood*; D015995:Prevalence; D011446:Prospective Studies; D012016:Reference Values; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology*
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D