OBJECTIVES: Hormone oral contraceptives affected ascorbic acid status adversely in young women. In vitro, estrogens and progesterone inhibited ascorbic acid accumulation in intestinal cells. This is a pilot study to examine the relation between hormone replacement therapy (HRT) and plasma ascorbic acid levels among a group of healthy non-smoking postmenopausal women. METHODS: Healthy non-smoking postmenopausal women aged 48-72 years, 34 with HRT and 21 without HRT, were recruited in summer, 1997. Their fasting plasma ascorbic acid levels were measured and information on ascorbic acid intakes (diet and supplements) was collected through questionnaires. RESULTS: Women taking HRT in this study did not have significantly lower plasma ascorbic acid levels compared with non-HRT users. When subjects were further divided into groups based on ascorbic acid supplementation, HRT users without supplement had a lower mean plasma ascorbic acid level (54+/-16 microM, n=10) compared with non-HRT users (66+/-14 microM, n=12) (P=0.08 for the effect of therapy). HRT users and non-users taking ascorbic acid supplement had similar plasma levels (66+/-10 microM, n=24; 66+/-12 microM, n=9, respectively). CONCLUSION: HRT does not affect ascorbic acid status of healthy well-nourished non-smoking postmenopausal women that are using ascorbic acid supplement. Future larger case-control or supplement intervention study is needed.