title: Parenteral vitamin B12 therapy of hyperhomocysteinemia in end-stage renal disease.
abstract: BACKGROUND
  End-stage renal disease (ESRD) is associated with moderately severe hyperhomocysteinemia that is incompletely normalized by oral folic acid therapy and vitamin B12.
  
  
  METHODS
  We administered 1 mg hydroxocobalamin parenterally at 14-day intervals to vitamin B12-replete hemodialysis patients who were already consuming 6 mg folic acid daily by mouth. Plasma total homocysteine (tHcy), serum folate, vitamin B12 and methylmalonate were measured immediately before and after 4 and 8 weeks of therapy.
  
  
  RESULTS
  Serum folate concentrations were consistently over 25 times the upper normal limit. Hydroxocobalamin therapy increased serum vitamin B12 concentrations 14-fold (p < 0.001) and reduced plasma tHcy by 23% from 29.7 +/- 2.9 to 22.8 +/- 2.5 micromol/L (p < 0.01); serum methylmalonate decreased by one-third (p < 0.05).
  
  
  CONCLUSIONS
  These results demonstrate the Hcy-lowering potential of parenteral vitamin B12 in folic acid supplemented vitamin B12-replete hemodialysis patients, and indicate the need for formal dose-optimization studies of this simple, inexpensive and promising approach to Hcy reduction in end-stage renal disease.
authors.affiliation: Lady Davis Institute for Medical Research, Sir Mortimer B. Davis-Jewish General Hospital, Montréal, Que. l.hoffer@mcgill.ca
authors.forename: L John
authors.initials: LJ
authors.lastname: Hoffer
authors.forename: Kelly M
authors.initials: KM
authors.lastname: Elian
mesh_terms: D000284:Administration, Oral; D000368:Aged; D005492:Folic Acid / Q000097:blood / Q000627:therapeutic use; D006801:Humans; D020138:Hyperhomocysteinemia / Q000188:drug therapy*; D007676:Kidney Failure, Chronic / Q000628:therapy*; D008764:Methylmalonic Acid / Q000097:blood; D008875:Middle Aged; D010288:Parenteral Nutrition; D013997:Time Factors; D014805:Vitamin B 12 / Q000627:therapeutic use*; D014806:Vitamin B 12 Deficiency / Q000628:therapy
chemical_list: D008764:Methylmalonic Acid; D005492:Folic Acid; D014805:Vitamin B 12