Serum vitamin A status in women users of lowdose oral contraceptives and in postmenopausal women taking hormone replacement therapy.

Background: One of the most important nonenzymatic antioxidant defense systems is vitamin A, and is considered as an important dietary agent for reducing cardiovascular diseases. Objective: The objective of this study was to investigate the serum vitamin A status in women who used low-dose oral contraceptives (OCs) containing 0.15 mg levonorgestrol and 0.03 mg ethinyl estradiol and also in postmenopausal women who took hormone replacement therapy (HRT) and comparison of them with control group. Materials and Methods: In this case – control study one hundred and thirty nine healthy, non pregnant and non lactating women with a mean age of 32 years old (70 were OCs users and 69 were non-OCs Users) and sixty healthy postmenopausal women, with a mean age of 51 years old (30 were under HRT treatment and 30 were untreated) were studied using biochemical procedures, anthropometrics measurements and interview with the subjects. Data were analyzed using the t-test and x2 test. Findings: There was no significant difference between either OCs and non-OCs users or HRT and non-HRT groups in terms of mean BMI, number of pregnancies and dietary intakes of vitamin A and fiber. Mean serum vitamin A level in OCs Users was significantly (p<0. 001) higher than that of non – OCs users (79.97±23.56 μg/dl vs. 64.56±22.15 μg/dl). There was no significant difference between HRT and non-HRT groups in terms of mean serum vitamin A level (71.76±15.91 μg/dl and 67.65±22.39 μg/dl respectively). There was a significant (P<0.004) relationship between serum Vitamin A status and use of OCs analyzed using x2 test. This test did not show significant relationship in postmenopausal women. Conclusions: Using OCs and subsequent hormonal alteration are an effective factor for increasing serum vitamin A level in childbearing aged women. Taking HRT has not resulted in altered vitamin A levels in postmenopausal women.