Effect of B-group vitamins and antioxidant vitamins on hyperhomocysteinemia: a double-blind, randomized, factorial-design, controlled trial.
Mild hyperhomocysteinemia is accepted as a risk factor for premature cardiovascular disease. In a population with a high prevalence of cardiovascular disease, we screened a group of clinically healthy working men aged 30-49 y (n = 509) for plasma homocysteine and 5,10-methylene tetrahydrofolate reductase (MTHFR) genotype status. Those with mildly elevated homocysteine concentrations (> or = 8.34 micromol/L) were selected for intervention. In a randomized, factorial-design, controlled trial we assessed the effects of B-group vitamins and antioxidant vitamin supplementation on homocysteine concentrations. The 132 men were randomly assigned to one of four groups: supplementation with B-group vitamins alone (1 mg folic acid, 7.2 mg pyridoxine, and 0.02 mg cyanocobalamin), antioxidant vitamins alone (150 mg ascorbic acid, 67 mg RRR-alpha-tocopherol, and 9 mg beta-carotene), B-group vitamins with antioxidant vitamins, or placebo. Intervention was double-blind. A total of 101 men completed the 8-wk intervention. When homocysteine concentrations were analyzed by group, significant (P < 0.001) decreases (32.0% and 30.0%, respectively) were observed in both groups receiving B-group vitamins either with or without antioxidants. The effect of B-group vitamins alone over 8 wk was a reduction in homocysteine concentrations of 27.9% (95% CI: 22.0%, 33.3%; P < 0.001) whereas antioxidants alone produced a nonsignificant increase of 5.1% (95% CI: -2.8%, 13.6%; P = 0.21). There was no evidence of any interaction between the two groups of vitamins. The effect of B-group vitamin supplementation seemed to depend on MTHFR genotype. Supplementation with the B-group vitamins with or without antioxidants reduced homocysteine in the men with mildly elevated concentrations, and hence may be effective in reducing cardiovascular risk.
Woodside
J V
JV
School of Clinical Medicine, The Queen's University of Belfast, United Kingdom. p9495754@qub.ac.uk
Yarnell
J W
JW
McMaster
D
D
Young
I S
IS
Harmon
D L
DL
McCrum
E E
EE
Patterson
C C
CC
Gey
K F
KF
Whitehead
A S
AS
Evans
A
A
D000328:Adult; D000367:Age Factors; D000704:Analysis of Variance; D000975:Antioxidants / Q000008:administration & dosage / Q000627:therapeutic use*; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D015992:Body Mass Index; D002784:Cholesterol / Q000097:blood; D003971:Diastole; D019587:Dietary Supplements; D004311:Double-Blind Method; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D005492:Folic Acid / Q000008:administration & dosage / Q000627:therapeutic use*; D006710:Homocysteine / Q000097:blood* / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011736:Pyridoxine / Q000008:administration & dosage / Q000627:therapeutic use*; D012016:Reference Values; D012907:Smoking; D013599:Systole; D014280:Triglycerides / Q000097:blood; D014805:Vitamin B 12 / Q000008:administration & dosage / Q000627:therapeutic use*; D014810:Vitamin E / Q000008:administration & dosage / Q000627:therapeutic use; D019207:beta Carotene / Q000008:administration & dosage / Q000627:therapeutic use
D000975:Antioxidants; D014280:Triglycerides; D019207:beta Carotene; D006710:Homocysteine; D014810:Vitamin E; D005492:Folic Acid; D002784:Cholesterol; D011736:Pyridoxine; D014805:Vitamin B 12; D001205:Ascorbic Acid