Effect of supplementation with B vitamins and antioxidants on levels of asymmetric dimethylarginine (ADMA) and C-reactive protein (CRP): a double-blind, randomised, factorial design, placebo-controlled trial.
OBJECTIVE
Cardiovascular risk factors such as elevated levels of asymmetric dimethylarginine (ADMA)/C-reactive protein (CRP) and homocysteine are potentially related to essential micronutrients such as certain B vitamins and antioxidant vitamins. The aim of the present study was to investigate whether supplementation with moderate doses of B vitamins and/or antioxidants could alter either ADMA and/or CRP concentrations in middle-aged, apparently healthy men with mildly elevated homocysteine levels.


METHODS
A randomised, double-blind, factorial design, intervention study was carried out on 132 men with mildly elevated homocysteine levels, allocated to four groups (a) B vitamins alone--1 mg folic acid, 7.2 mg pyridoxine, 0.02 mg cyanocobalamin daily, (b) antioxidants alone--150 mg ascorbic acid, 67 mg vitamin E, 9 mg β-carotene daily, (c) B vitamins with antioxidant vitamins, or (d) placebo. A total of 101 men completed the study to 8 weeks.


RESULTS
When the percentage of baseline ADMA and CRP was examined at 8 weeks, no statistically significant differences were observed between the four groups (p = 0.21 and p = 0.90, respectively). Similar non-significant results were observed when analysis was stratified based on baseline CRP levels (<1.0 mg/L, p = 0.10; ≥1.0 mg/L, p = 0.64) and smoking status (all p ≥ 0.05).


CONCLUSIONS
Supplementation with moderate doses of B vitamins and/or antioxidants did not alter either ADMA or CRP concentrations in these middle-aged, apparently healthy men with mildly elevated homocysteine levels.
O'Doherty
Mark G
MG
School of Medicine, Dentistry and Biomedical Sciences, Queen's University, Belfast, UK. m.odoherty@qub.ac.uk
Gilchrist
Sarah E C M
SE
Young
Ian S
IS
McKinley
Michelle C
MC
Yarnell
John W G
JW
Gey
K Fred
KF
Evans
Alun
A
Skidmore
Paula M L
PM
Woodside
Jayne V
JV
D000328:Adult; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D001120:Arginine / Q000031:analogs & derivatives* / Q000097:blood; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000494:pharmacology; D015415:Biomarkers / Q000097:blood / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects; D002097:C-Reactive Protein / Q000378:metabolism*; D002318:Cardiovascular Diseases / Q000517:prevention & control; D002784:Cholesterol / Q000097:blood; D019587:Dietary Supplements; D004311:Double-Blind Method; D006710:Homocysteine / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D020011:Protective Agents / Q000008:administration & dosage / Q000494:pharmacology*; D014280:Triglycerides / Q000097:blood; D014803:Vitamin B Complex / Q000008:administration & dosage / Q000494:pharmacology*; D014810:Vitamin E / Q000008:administration & dosage / Q000494:pharmacology; D019207:beta Carotene / Q000008:administration & dosage / Q000494:pharmacology
D000975:Antioxidants; D015415:Biomarkers; D020011:Protective Agents; D014280:Triglycerides; D019207:beta Carotene; D006710:Homocysteine; D014803:Vitamin B Complex; D014810:Vitamin E; C018524:N,N-dimethylarginine; D002097:C-Reactive Protein; D001120:Arginine; D002784:Cholesterol; D001205:Ascorbic Acid
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