Plasma ascorbate and vitamin E levels in Hong Kong Chinese

Objective: To describe fasting plasma total-and lipid standardised-vitamin E and ascorbate concentrations in Hong Kong Chinese subjects, and to explore age-, diet- and sex-related differences. Design: Observational study. Setting: Hong Kong. Subjects: One hundred and fifty randomly selected Chinese subjects. Interventions: Fasting plasma concentrations of ascorbate, total vitamin E and lipid standardised vitamin E (Vit E-LS expressed as mu mol vitamin E/mmol total cholesterol plus triglycerides) were measured. Results: Total vitamin E concentrations ranged from 6-53 mu mol/l (mean 24; s.d. 8.5), and Vit E-LS from 0.85-7.09 mu mol/mmol (mean 3.61; s.d. 1.19). Plasma Vit E-LS concentrations in women were higher (P = 0.02) than in men: mean (median) concentrations 3.82 (3.88) and 3.37 (3.28) mu mol/mmol, respectively. Vit E-LS concentrations in men decreased with age. Mean (s.d.) plasma ascorbate concentrations in men and women were 49.7 (14.0) and 51.6 (21.6) mu mol/l respectively, and did not show the significant age-and sex-differences reportedly found in Western studies. Conclusions: The hypothesis that Hong Kong Chinese, with their low risk of CHD, might have high Vit E-LS levels in fasting plasma is not supported by the results obtained. Moreover, results showed male-female differences and, in men, a previously unreported age-related decrease in plasma Vit E-LS concentration which cannot be accounted for by concomitant differences in dietary intake of vitamin E alone. Results also suggest that the age-and sex-differences in plasma ascorbate seen in Western populations can be avoided by increased vitamin C intake.