title: Folic acid supplementation in early pregnancy and asthma in children aged 6 years.
abstract: OBJECTIVE
  The objective of the study was to assess whether folic acid intake during the first trimester of pregnancy is related to asthma in the offspring by the age of 6 years.
  
  
  METHODS
  This was a prospective cohort study of 1499 women who were followed up from the first trimester of pregnancy. Their children were followed up until they were 6 years old.
  
  
  RESULTS
  Fifty-one percent of the women used folic acid in the month before conception and 88% in the third month of pregnancy. The adjusted odds ratio for asthma per 100 μm increase in the average daily intake of folic acid was 0.98 (95% confidence interval, 0.93-1.04). For categories of daily folate intake, there was no evidence of associations with childhood asthma or evidence of any dose response relation for any time period (all P(trend) > .05).
  
  
  CONCLUSIONS
  Our results do not support any association of folic acid supplementation in pregnancy and asthma risk in offspring by age 6 years.
authors: Yale Center for Perinatal, Pediatric, and Environmental Epidemiology, Yale School of Public Health, New Haven, CT 06510, USA. michael.bracken@yale.edu
authors: Marit P
authors: MP
authors: Martinussen
authors: Kari R
authors: KR
authors: Risnes
authors: Geir W
authors: GW
authors: Jacobsen
authors: Michael B
authors: MB
authors: Bracken
mesh_terms: D000328:Adult; D001249:Asthma / Q000453:epidemiology*; D002648:Child; D015331:Cohort Studies; D019587:Dietary Supplements / Q000009:adverse effects*; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage / Q000009:adverse effects*; D006801:Humans; D011247:Pregnancy; D011446:Prospective Studies; D012306:Risk; D014481:United States / Q000453:epidemiology; D014803:Vitamin B Complex / Q000008:administration & dosage / Q000009:adverse effects*; D055815:Young Adult
chemical_list: D014803:Vitamin B Complex; D005492:Folic Acid