title: [Impact of weekly administration of folic acid on folic acid blood levels].
abstract: OBJECTIVE
  To evaluate the effect of weekly administration of 5 mg. folic acid (FA) intake on folic acid blood levels.
  
  
  METHODS
  This concurrent comparative study was conducted in 1998, in urban and rural areas of Nuevo Leon State, Mexico. The study population consisted of 74 women who delivered a child during 1997, 39 of whom had a child with a neural tube defect. Women were given 5 mg. of folic acid, weekly for 3 months. Blood levels of folic acid were determined by radioimmunoassay (RIA) at baseline, and a week after taking the last folic acid dose. Data are presented as means and standard deviations.
  
  
  RESULTS
  Ninety per cent of the women had significantly increased folic acid intraerythrocytary blood levels. Red cell folate increased from 150.49 +/- 31.17 ng/ml to 184.21 +/- 35.53 ng/ml (p < 0.005). Plasma folate increased from 5.93 +/- 1.98 ng/ml a 7.03 +/- 2.5 ng/ml (p < 0.05). Eighty-two per cent of women reached intracellular levels above 160 ng/ml.
  
  
  CONCLUSIONS
  The weekly administration of folic acid is a simple and efficient method that could be used to supplement this vitamin to low-income populations. The English version of this paper is available at: http://www.insp.mx/salud/index.html.
authors.affiliation: Departamento de Patología, Unidad de Genética y Defectos Congénitos, Facultad de Medicina, Universidad Autónoma de Nuevo León (NL), Monterrey, NL, México. laurmart@ccr.dsi.uanl.mx
authors.forename: L E
authors.initials: LE
authors.lastname: Martínez-de Villarreal
authors.forename: C
authors.initials: C
authors.lastname: Limón-Benavides
authors.forename: R
authors.initials: R
authors.lastname: Valdez-Leal
authors.forename: M A
authors.initials: MA
authors.lastname: Sánchez-Peña
authors.forename: J Z
authors.initials: JZ
authors.lastname: Villarreal-Pérez
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage* / Q000097:blood*; D006801:Humans; D007231:Infant, Newborn; D008800:Mexico; D009436:Neural Tube Defects / Q000517:prevention & control*; D011247:Pregnancy; D011863:Radioimmunoassay; D012424:Rural Population; D013997:Time Factors; D014505:Urban Population
chemical_list: D005492:Folic Acid