title: Efficacy of B vitamins in lowering homocysteine in older men: maximal effects for those with B12 deficiency and hyperhomocysteinemia.
abstract: OBJECTIVE
  A higher plasma concentration of total homocysteine (tHcy) is associated with a greater risk of cardiovascular events. Previous studies, largely in younger individuals, have shown that B vitamins lowered tHcy by substantial amounts and that this effect is greater in people with higher tHcy and lower folate levels.
  
  
  METHODS
  We undertook a 2-year, double-blind, placebo-controlled, randomized trial in 299 men aged > or =75 years, comparing treatment with a daily tablet containing 2 mg of folate, 25 mg of B6, and 400 microg of B12 or placebo. The study groups were balanced regarding age (mean+/-SD, 78.9+/-2.8 years), B vitamins, and tHcy at baseline.
  
  
  RESULTS
  Among the 13% with B12 deficiency, the difference in mean changes in treatment and control groups for tHcy was 6.74 micromol/L (95% CI, 3.94 to 9.55 micromol/L) compared with 2.88 micromol/L (95% CI, 0.07 to 5.69 micromol/L) for all others. Among the 20% with hyperhomocysteinaemia, the difference between mean changes in treatment and control groups for men with high plasma tHcy compared with the rest of the group was 2.8 micromol/L (95% CI, 0.6 to 4.9 micromol/L). Baseline vitamin B12, serum folate, and tHcy were significantly associated with changes in plasma tHcy at follow-up (r=0.252, r=0.522, and r=-0.903, respectively; P=0.003, <0.001, and <0.001, respectively) in the vitamin group.
  
  
  CONCLUSIONS
  The tHcy-lowering effect of B vitamins was maximal in those who had low B12 or high tHcy levels. Community-dwelling older men, who are likely to be deficient in B12 or have hyperhomocysteinemia, may be most likely to benefit from treatment with B vitamins.
authors.affiliation: School of Medicine and Pharmacology, University of Western Australia, Perth, Australia. leonflic@cyllene.uwa.edu.au
authors.forename: Leon
authors.initials: L
authors.lastname: Flicker
authors.forename: Samuel D
authors.initials: SD
authors.lastname: Vasikaran
authors.forename: Jenny
authors.initials: J
authors.lastname: Thomas
authors.forename: John M
authors.initials: JM
authors.lastname: Acres
authors.forename: Paul
authors.initials: P
authors.lastname: Norman
authors.forename: Konrad
authors.initials: K
authors.lastname: Jamrozik
authors.forename: Graeme J
authors.initials: GJ
authors.lastname: Hankey
authors.forename: Osvaldo P
authors.initials: OP
authors.lastname: Almeida
mesh_terms: D000368:Aged; D019587:Dietary Supplements; D004311:Double-Blind Method; D005492:Folic Acid / Q000494:pharmacology; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D020138:Hyperhomocysteinemia / Q000097:blood / Q000628:therapy*; D008297:Male; D010919:Placebos; D013997:Time Factors; D016896:Treatment Outcome; D014805:Vitamin B 12 / Q000494:pharmacology; D014806:Vitamin B 12 Deficiency / Q000097:blood / Q000628:therapy*; D014803:Vitamin B Complex / Q000494:pharmacology*
chemical_list: D010919:Placebos; D006710:Homocysteine; D014803:Vitamin B Complex; D005492:Folic Acid; D014805:Vitamin B 12