title: Hyperhomocysteinemia and the response to vitamin supplementation.
abstract: The long-term vitamin requirements of men (n = 22) with moderate hyperhomocysteinemia (plasma total homocysteine concentration > 16.3 mumol/l) were investigated over a period of 48 weeks. An initial 6-week period of vitamin supplementation (1.0 mg folic acid, 10 mg pyridoxine, 0.05 mg cyanocobalamin) reduced plasma homocysteine levels 54.7% (P < 0.001). However, 18 weeks after vitamin therapy was discontinued, only seven participants (subgroup A) still had plasma homocysteine levels of 16.3 mumol/l or lower. The remainder of the participants (subgroup B) required a second 6-week period of vitamin therapy to normalize the elevated plasma homocysteine levels. Substitution of vitamin supplementation by dietary guidelines to increase folate intake from food products failed to maintain normal plasma homocysteine levels in participants from subgroup B. Long-term vitamin supplementation may be required in some individuals to prevent hyperhomocysteinemia.
authors.affiliation: Department of Chemical Pathology, Faculty of Medicine, University of Pretoria.
authors.forename: J B
authors.initials: JB
authors.lastname: Ubbink
authors.forename: A
authors.initials: A
authors.lastname: van der Merwe
authors.forename: W J
authors.initials: WJ
authors.lastname: Vermaak
authors.forename: R
authors.initials: R
authors.lastname: Delport
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004032:Diet; D005492:Folic Acid / Q000627:therapeutic use*; D005500:Follow-Up Studies; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011736:Pyridoxine / Q000627:therapeutic use*; D014805:Vitamin B 12 / Q000627:therapeutic use*
chemical_list: D006710:Homocysteine; D005492:Folic Acid; D011736:Pyridoxine; D014805:Vitamin B 12