title: [Serum folate levels in adolescent population in Madrid, Spain].
abstract: OBJECTIVE
  Serum folate concentrations in children are essential to establish values which allow to compare different regions or countries, and raise the possibility of fortifying diet with group B vitamins and folic acid as a secondary prevention against cardiovascular diseases.
  
  
  METHODS
  A cross-sectional epidemiological study was performed to assess serum folate levels in school children, aged 13-15 years, in Madrid. Folate and vitamin B12 determinations were determined in blood samples of fasting children. Genotype C677T of methylentetrahydrofolate reductase (MTHFR) enzyme was determined by polymerase chain reaction.
  
  
  RESULTS
  Average folate levels obtained in our study were 7.83 nmol/l (95% confidence interval, 7.42 to 8.23 nmol/l). Median was 6.89 nmol/l (interquartilic range: 5.30 to -9.30 nmol/l). No statistically significant differences were found by gender, age or presence of menstruation. Serum folate concentration decreased significantly with the mutation of the C677T genotype for MTHFR. Prevalence of deficits of folate (< 5.3 nmol/l) was 23.8% and raised significantly with the mutation of the C677T genotype for MTHFR: 18.8% for CC, 20.4% for CT, and 46.7% for TT. This effect was mainly observed in girls after menstruation.
  
  
  CONCLUSIONS
  Homozygosis mutation in C677T genotype of the enzyme MTHFR induces lower folate levels, mainly in girls after menstruation. 5.3 nmol/l is proposed as a threshold to define deficient serum folate levels in the Spanish adolescent population.
authors.affiliation: Area de Medicina Preventiva y Salud Pública, Departamento de Ciencias de la Salud, Universidad Rey Juan Carlos, Laboratorio de Lípidos, Fundación Jiménez Díaz, Madrid, España. ruth.gil@urjc.es
authors.forename: Ruth
authors.initials: R
authors.lastname: Gil
authors.forename: Jesús
authors.initials: J
authors.lastname: Esteban
authors.forename: Valentín
authors.initials: V
authors.lastname: Hernández
authors.forename: Beatriz
authors.initials: B
authors.lastname: Cano
authors.forename: Manuel
authors.initials: M
authors.lastname: de Oya
authors.forename: Angel
authors.initials: A
authors.lastname: Gil
mesh_terms: D000293:Adolescent; D003430:Cross-Sectional Studies; D005260:Female; D005492:Folic Acid / Q000097:blood*; D005838:Genotype; D006801:Humans; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics; D009154:Mutation; D013030:Spain
chemical_list: D005492:Folic Acid; D042965:Methylenetetrahydrofolate Reductase (NADPH2)