Lack of effect of acute oral ingestion of vitamin C on oxidative stress, arterial stiffness or blood pressure in healthy subjects.
Vitamin C is a potent antioxidant in vitro and has been reported to act as a vasodilator, possibly by increasing nitric oxide bioavailability. This study examined the antioxidant and vascular effects of a single large oral dose of vitamin C in 26 healthy human volunteers. Haemodynamic and oxidative DNA and lipid damage markers were measured for 8 h following an oral dose of 2 g vitamin C or placebo. Vitamin C had no effect on vasodilation (measured by augmentation index (mean change=0.04%, 90% CI=- 2.20% to 2.28%) or forearm blood flow (-0.19%/min (-0.68, 0.30)), in comparison to placebo) or on several markers of oxidative stress including DNA base oxidation products in blood cells, 8-hydroxy-2'-deoxyguanosine (8O HdG) in urine (0.068 (-0.009, 0.144)) or urinary or plasma total F(2)-isoprostanes (-0.005 ng/ml (-0.021, 0.010), -0.153 ng/mg (-0.319, 0.014), respectively).
Kelly
Ronan P
RP
Lilly-NUS Centre for Clinical Pharmacology, Level 6, Clinical Research Centre (MD 11), National University of Singapore, Singapore. ronan.kelly@lilly.com
Poo Yeo
Kwee
K
Isaac
Helen B
HB
Lee
Chung-Yung J
CY
Huang
Shan Hong
SH
Teng
Lorraine
L
Halliwell
Barry
B
Wise
Stephen D
SD
D000284:Administration, Oral; D000328:Adult; D000975:Antioxidants / Q000378:metabolism; D001158:Arteries / Q000187:drug effects*; D001205:Ascorbic Acid / Q000378:metabolism / Q000494:pharmacology*; D015415:Biomarkers / Q000378:metabolism; D001794:Blood Pressure; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008055:Lipids / Q000737:chemistry; D008297:Male; D018384:Oxidative Stress; D010919:Placebos; D014665:Vasodilator Agents / Q000494:pharmacology
D000975:Antioxidants; D015415:Biomarkers; D008055:Lipids; D010919:Placebos; D014665:Vasodilator Agents; D001205:Ascorbic Acid