Consumption of Vitamin A-Rich Foods Is Associated With Increased Retinol Binding Protein in Nepali Pregnant Women

Objectives: We assessed the association of vitamin A dietary patterns with retinol binding protein (RBP), a biomarker of vitamin A status, during the 2nd and 3rd trimesters of Nepali pregnant women. Methods: This secondary analysis included 1058 women in their 2nd and 3rd trimesters who were treated for night blindness (XN) with 25,000 IUs of vitamin A for 4 weeks. Measures of vitamin A dietary patterns via a Food Frequency Questionnaire, RBP and C-reactive protein (CRP) measured via blood spots, capillary hemoglobin (Hb) (BRINDA-adjusted), and sociodemographic and medical history data were collected at baseline before the start of vitamin A supplementation. 'Yes/no' variables were created for vitamin A-rich foods consumed in the last week and the total number of foods consumed was computed. We used simple linear regression to assess associations of independent variables with RBP and backward stepwise regression to assess associations of vitamin A dietary patterns and RBP controlling for education, gestational age, CRP, and Hb. This analysis did not control for oil/fat consumption. Results: Participants were 23.6±4.1 (mean±SD) years old on average, 83% had no formal education, and 18% reported XN during previous pregnancies. The mean number of weeks gestation was 26.1±6.4. Mean RBP, CRP, and Hb levels were 0.87±0.28 μmol/l, 3.4±6.3 mg/l, and 10.6±1.7 g/dl, respectively. On average, women ate 1.5 (range 0-6) vitamin A-rich foods in a week. Consumption of dark leafy green vegetables, yellow/orange flesh fruits, and liver was significantly correlated (p< 0.05) with RBP levels. Higher Hb and lower CRP levels, history of XN, and gestation were significantly associated with RBP levels at baseline (p< 0.05). After adjusting for Hb, CRP, education, history of XN, and gestation, consumption of vitamin A-rich foods was significantly associated with RBP (p< 0.05). Conclusions: A modest consumption of vitamin A-rich foods weekly, including dark leafy green vegetables, yellow/orange flesh fruits, and liver can improve vitamin A status. Dietary vitamin A interventions should target women with low Hb, high CRP, less education, a history of XN during pregnancy, and later gestation for the greatest impact.