title: Evaluation of nutritional and genetic determinants of total homocysteine, methylmalonic acid and S-adenosylmethionine/S-adenosylhomocysteine values in Brazilian childbearing-age women.
abstract: BACKGROUND
  Cobalamin (Cbl) and folate deficiencies and gene polymorphism of key enzymes or carriers can impair homocysteine metabolism and may change the serum values of S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH). We investigated the nutritional and genetic determinants for total homocysteine (tHcy), methylmalonic acid (MMA) and SAM/SAH in healthy Brazilian childbearing-age women.
  
  
  METHODS
  Serum concentrations of Cbl, folate, red blood cell folate, ferritin, tHcy, MMA, SAM, SAH and other metabolites were measured in 102 healthy unrelated women. The genotypes for MTHFR C677T, MTHFR A1298C, MTR A2756G, MTRR A66G, TC2 C776G, TC2 A67G and RFC1 A80G gene polymorphisms were identified by PCR-RFLP.
  
  
  RESULTS
  Serum folate and Cbl were inversely correlated with tHcy and serum MMA, respectively. Cbl deficiency was associated with increased MMA and reduced alpha-aminobutyrate, serine and N-methylglycine concentrations. No variable was associated with SAM/SAH ratio. In addition, gene polymorphisms were not selected as determinants for tHcy, MMA and SAM/SAH ratio. Iron, Cbl and folate deficiencies were found respectively in 30.4%, 22.5% and 2.0% of individuals studied.
  
  
  CONCLUSIONS
  There was a high frequency of Cbl and iron deficiency in this group of childbearing-age women. Serum folate and Cbl were the determinants of serum tHcy and MMA concentration, respectively.
authors.affiliation: Department of Clinical Chemistry and Toxicology, School of Pharmaceutical Sciences, University of Sao Paulo, Brazil.
authors.forename: Patrícia R
authors.initials: PR
authors.lastname: Barbosa
authors.forename: Sally P
authors.initials: SP
authors.lastname: Stabler
authors.forename: Renata
authors.initials: R
authors.lastname: Trentin
authors.forename: Felipe R
authors.initials: FR
authors.lastname: Carvalho
authors.forename: André D
authors.initials: AD
authors.lastname: Luchessi
authors.forename: Rosario D C
authors.initials: RD
authors.lastname: Hirata
authors.forename: Mario H
authors.initials: MH
authors.lastname: Hirata
authors.forename: Robert H
authors.initials: RH
authors.lastname: Allen
authors.forename: Elvira M
authors.initials: EM
authors.lastname: Guerra-Shinohara
mesh_terms: D000328:Adult; D000375:Aging / Q000235:genetics / Q000502:physiology; D000483:Alleles; D018798:Anemia, Iron-Deficiency / Q000097:blood; D001361:Avitaminosis / Q000097:blood; D001938:Brazil; D005260:Female; D005838:Genotype; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008764:Methylmalonic Acid / Q000097:blood*; D009747:Nutritional Physiological Phenomena; D011110:Polymorphism, Genetic / Q000235:genetics*; D012098:Reproduction; D012435:S-Adenosylhomocysteine / Q000097:blood*; D012436:S-Adenosylmethionine / Q000097:blood*; D014805:Vitamin B 12 / Q000097:blood; D014815:Vitamins / Q000378:metabolism
chemical_list: D014815:Vitamins; D006710:Homocysteine; D012436:S-Adenosylmethionine; D008764:Methylmalonic Acid; D012435:S-Adenosylhomocysteine; D014805:Vitamin B 12