title: Folate, but not vitamin B-12 status, predicts respiratory morbidity in north Indian children.
abstract: BACKGROUND
  Vitamin deficiencies are often part of malnutrition, which predisposes to acute lower respiratory tract infections.
  
  
  OBJECTIVE
  The objective was to measure the association between cobalamin and folate status and subsequent respiratory morbidity.
  
  
  METHODS
  A prospective cohort study was conducted in 2482 children aged 6-30 mo nested in a zinc supplementation trial. We measured plasma concentrations of folate, cobalamin, methylmalonic acid, and total homocysteine (tHcy) and followed the children for 4 mo.
  
  
  RESULTS
  We observed 1176 episodes of acute lower respiratory tract infections. Children with folate concentrations in the lowest quartile (interquartile range: 6.4-20.0 nmol/L) had a 44% higher incidence [adjusted incidence rate ratio (IRR): 1.44; 95% CI: 1.23, 1.70] of acute lower respiratory tract infections than did children in the other 3 quartiles. For tHcy, the IRR was 1.24 (1.07, 1.40) in a comparison of those in the highest quartile with those in the other quartiles. Breastfeeding was associated with high folate concentrations and protection against subsequent respiratory tract infections. This protection was significantly and substantially reduced after adjustment for plasma folate concentrations at baseline. Compared with the children in the other 3 quartiles, the IRR for being in the lowest quartile of cobalamin was 1.13 (0.76, 1.03) and for being in the highest quartile of methylmalonic acid was 1.12 (0.96, 1.31).
  
  
  CONCLUSIONS
  Poor folate status appears to be an independent risk factor for lower respiratory tract infections in young children. This study also suggests that the protective effect of breastfeeding is partly mediated by folate provided through breast milk.
authors.affiliation: Centre for International Health, University of Bergen, Bergen, Norway.
authors.forename: Tor A
authors.initials: TA
authors.lastname: Strand
authors.forename: Sunita
authors.initials: S
authors.lastname: Taneja
authors.forename: Nita
authors.initials: N
authors.lastname: Bhandari
authors.forename: Helga
authors.initials: H
authors.lastname: Refsum
authors.forename: Per M
authors.initials: PM
authors.lastname: Ueland
authors.forename: Håkon K
authors.initials: HK
authors.lastname: Gjessing
authors.forename: Rajiv
authors.initials: R
authors.lastname: Bahl
authors.forename: Joern
authors.initials: J
authors.lastname: Schneede
authors.forename: Maharaj K
authors.initials: MK
authors.lastname: Bhan
authors.forename: Halvor
authors.initials: H
authors.lastname: Sommerfelt
mesh_terms: D000208:Acute Disease; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D005492:Folic Acid / Q000097:blood*; D006710:Homocysteine / Q000097:blood; D006801:Humans; D015994:Incidence; D007194:India / Q000453:epidemiology; D007223:Infant; D008297:Male; D008764:Methylmalonic Acid / Q000097:blood; D015999:Multivariate Analysis; D011446:Prospective Studies; D012044:Regression Analysis; D012141:Respiratory Tract Infections / Q000097:blood* / Q000453:epidemiology*; D012307:Risk Factors; D014805:Vitamin B 12 / Q000097:blood*
chemical_list: D006710:Homocysteine; D008764:Methylmalonic Acid; D005492:Folic Acid; D014805:Vitamin B 12