title: Early-pregnancy maternal vitamin D status and maternal hyperglycaemia.
abstract: OBJECTIVE
  To estimate the association between serum 25-hydroxyvitamin D concentrations and maternal hyperglycaemia (post-load glucose concentration ≥ 7.5 mmol/l).
  
  
  METHODS
  Pregnant women (n = 429; 61% black, 36% obese, 45% smokers) enrolled in a cohort study at <16 weeks gestation. Non-fasting blood samples were assayed for serum 25-hydroxyvitamin D at enrolment. At 24-28 weeks gestation, maternal hyperglycaemia was determined using a 50-g 1-h oral glucose challenge test.
  
  
  RESULTS
  A total of 67% of women had 25-hydroxyvitamin D concentrations < 50 nmol/l and 11% had maternal hyperglycaemia. Among smokers, each 23-nmol/l increase in serum 25-hydroxyvitamin D was associated with a reduction in the odds of maternal hyperglycaemia [odds ratio: 0.30 (95% CI: 0.13, 0.68)] after adjustment for parity, race/ethnicity, age, pre-pregnancy BMI, marital status, income, family history of diabetes, and gestational age of gestational diabetes mellitus screening. Among non-smokers, we found no association between early pregnancy vitamin D status and maternal hyperglycaemia.
  
  
  CONCLUSIONS
  Smoking status may modify the relationship between poor maternal vitamin D status and maternal hyperglycaemia.
authors.affiliation: Department of Epidemiology, University of Pittsburgh Graduate School of Public Health, Pittsburgh, PA, USA.
authors.forename: L E
authors.initials: LE
authors.lastname: Tomedi
authors.forename: H N
authors.initials: HN
authors.lastname: Simhan
authors.forename: L M
authors.initials: LM
authors.lastname: Bodnar
mesh_terms: D015652:25-Hydroxyvitamin D 2 / Q000097:blood; D000293:Adolescent; D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D002112:Calcifediol / Q000097:blood; D015331:Cohort Studies; D005260:Female; D006785:Hospitals, University; D006786:Hospitals, Urban; D006801:Humans; D006943:Hyperglycemia / Q000097:blood / Q000150:complications / Q000453:epidemiology* / Q000209:etiology; D039382:Maternal Nutritional Physiological Phenomena; D010414:Pennsylvania / Q000453:epidemiology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000453:epidemiology* / Q000209:etiology; D011261:Pregnancy Trimester, First; D011262:Pregnancy Trimester, Second; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications / Q000453:epidemiology*; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D015652:25-Hydroxyvitamin D 2; D002112:Calcifediol