Circulating levels of retinol, tocopherol and carotenoid in Nepali pregnant and postpartum women following long-term β-carotene and vitamin A supplementation

Objective: To characterize circulating carotenoid and tocopherol levels in Nepali women during pregnancy and post-partum and to determine the effects of β-carotene and vitamin A supplementation on their concentration in serum. Design: Randomized community supplementation trial. Setting: The study was carried out from 1994 to 1997 in the Southern, rural plains District of Sarlahi, Nepal. Subjects: A total of 1431 married women had an ascertained pregnancy, of whom 1186 (83%) provided an analyzable serum sample during pregnancy; 1098 (77%) provided an analyzable 3-4 months post-partum serum sample. Interventions: Women received a weekly dose of vitamin A (7000 μg RE), β-carotene (42 mg) or placebo before, during and after pregnancy. Serum was analyzed for retinol, α-tocopherol, γ-tocopherol, β-carotene, α-carotene, lycopene, lutein + zeaxanthin, and β-cryptoxanthin concentrations during mid-pregnancy and at ∼ 3 months post-partum. Results: Compared to placebo, serum retinol, β-carotene, γ-tocopherol, β-cryptoxanthin and lutein + zeaxanthin concentrations were higher among β-carotene recipients during pregnancy and, except for β-cryptoxanthin, at postpartum. In the vitamin A group, serum retinol and β-cryptoxanthin were higher during pregnancy, and retinol and γ-tocopherol higher at postpartum. Lutein + zeaxanthin was the dominant carotenoid, regardless of treatment group, followed by serum β-carotene. Serum lycopene level was lowest, and very low compared to the US population. Serum retinol was higher, and carotenoid and α-tocopherol lower, at postpartum than during pregnancy in all groups. Conclusions: Pregnant and lactating Nepali women have lower serum carotenoid and tocopherol levels than well-nourished populations. β-carotene supplementation appeared to increase levels of tocopherol and other carotenoids in this population.