Plasma ascorbate and vitamin E levels in Hong Kong Chinese

Abstract

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 μmol vitamin E/mmol total cholesterol plus triglycerides) were measured.

Results: Total vitamin E concentrations ranged from 6–53 μmol/l (mean 24; s.d. 8.5), and Vit E_LS from 0.85–7.09 μmol/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) μmol/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) μmol/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.

Sonsorship: This work was financially supported by The Hong Kong Polytechnic University and the UK/HK Joint Research Scheme.