Plasma Levels of Retinol, Carotenoids, and Tocopherols in Relation to Dietary Pattern among Pregnant Tanzanian Women

In Tanzania, as in other developing countries, dietary intake of nutrients in pregnant women is marginal or lower than the recommended intakes and therefore these women are at high risk for deficiencies. Our aim was to evaluate the relationship between diet and plasma levels of retinol, carotenoids, and α-tocopherol in the third trimester of pregnancy. Ninety pregnant women aged between 18 and 45 years were equally recruited from three villages. Seven-day food frequency data was collected by questionnaire. Plasma levels of retinol, carotenoids, and tocopherols were assessed by high-performance liquid chromatography (HPLC). Results indicated that cooked green leafy vegetables constituted the major source of provitamin A carotenoids, with low intake of yellow/orange fruits and preformed vitamin A. Lutein, lycopene, and β-carotene were the predominant carotenoids in the plasma with mean values of 1.61, 0.84, and 0.63 μmol/L, respectively. There was no significant correlation between frequencies of vegetable consumption and either plasma retinol or carotenoids. However, increased consumption of green leafy vegetables with oil, which increases bioavailability, was correlated with high plasma retinol levels (p = 0.03). Low retinol levels (≤ 0.70 μmol/L) were present in 26% of women. The mean plasma retinol concentration was 0.89 μmol/L and 63% of the women had values below 1.05 μmol/L. The mean plasma α-tocopherol concentration was 15.4 μmol/L and women with plasma retinol concentration > 1.05 μmol/L had significantly higher mean α-tocopherol than women with plasma retinol concentration ≤ 0.70 μmol/L (p ≤ 0.01). Twenty-four percent of the women were anemic (hemoglobin:Hb < 110 g/L) and the mean Hb value was 116.3 g/L.