title: Season of birth, neonatal vitamin D status, and cardiovascular disease risk at 35 y of age: a cohort study from Sweden.
abstract: BACKGROUND
  Lower vitamin D status during gestation may be associated with cardiovascular disease risk later in life. No studies have assessed this hypothesis with a follow-up time reaching beyond childhood.
  
  
  OBJECTIVE
  The objective was to assess the link between season of birth, neonatal 25-hydroxyvitamin D₃ [25(OH)D₃] status, and adult cardiovascular disease risk.
  
  
  METHODS
  Markers of cardiovascular and metabolic disease risk were measured in 284 subjects aged 35 y, born either at the end of the winter or at the end of the summer of 1975. In 275 of these 284 subjects, concentrations of neonatal 25(OH)D₃ were measured in dried blood samples by using a highly sensitive liquid chromatography-tandem mass spectroscopy method.
  
  
  RESULTS
  Subjects born after the winter had lower neonatal 25(OH)D₃ concentrations than did those born after the summer (31.5 compared with 48.5 nmol/L; P < 0.001). In regression analyses adjusted for sex, season of birth, postnatal age at neonatal sample collection, preterm birth, maternal age, education, smoking, fish consumption per week, exercise per week, and current 25-hydroxyvitamin D, higher neonatal 25(OH)D₃ (per 50 nmol/L) was associated with 25.8% (95% CI: 1.0%, 58.4%) higher fasting insulin in adult life, 29.6% (5.1%, 58.4%) higher triglycerides, and 4.64 (95% CI: 1.93, 7.36) mmol/L higher serum cholesterol in women. Neonatal 25(OH)D₃ (per 1 nmol/L) was directly associated with risk of adult overweight (OR: 1.03; 95% CI: 1.01, 1.05) and with adult obesity in women (OR: 1.09; 95% CI: 1.02, 1.17). Neonatal 25(OH)D₃ was not associated with adult aortic pulse wave velocity, blood pressure, fasting glucose, HDL, LDL, or C-reactive protein. Season of birth was not associated with any of the adult outcomes.
  
  
  CONCLUSIONS
  Higher neonatal 25(OH)D₃ was associated with higher fasting insulin, triglyceride, and cholesterol (in women) concentrations and with a higher risk of overweight at 35 y of age but not with other adult cardiovascular disease risk factors.
authors.affiliation: Clinical Epidemiology Unit, Department of Medicine, Solna, Karolinska Institutet, Stockholm, Sweden (PU); the Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden (PT, MH, and MN); and the Queensland Centre for Mental Health Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia (HS and DE).
authors.forename: Per
authors.initials: P
authors.lastname: Tornhammar
authors.forename: Peter
authors.initials: P
authors.lastname: Ueda
authors.forename: Martin
authors.initials: M
authors.lastname: Hult
authors.forename: Henry
authors.initials: H
authors.lastname: Simila
authors.forename: Darryl
authors.initials: D
authors.lastname: Eyles
authors.forename: Mikael
authors.initials: M
authors.lastname: Norman
mesh_terms: D000328:Adult; D000375:Aging; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000097:blood / Q000453:epidemiology / Q000209:etiology; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007227:Infant Nutritional Physiological Phenomena; D007231:Infant, Newborn; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood / Q000453:epidemiology / Q000209:etiology*; D009752:Nutritional Status; D009765:Obesity / Q000097:blood / Q000453:epidemiology / Q000209:etiology*; D050177:Overweight / Q000097:blood / Q000453:epidemiology / Q000209:etiology*; D012042:Registries; D012307:Risk Factors; D012621:Seasons; D012727:Sex Characteristics; D013548:Sweden / Q000453:epidemiology; D014808:Vitamin D Deficiency / Q000097:blood / Q000151:congenital / Q000503:physiopathology*
chemical_list: D015415:Biomarkers