Retinol, carotenoids, and tocopherols in the milk of lactating adolescents and relationships with plasma concentrations
Received 14 February 2007; accepted 21 October 2007. published online 30 November 2007.
Abstract
Objective
We determined the concentrations of retinol, carotenoids, and tocopherols in breast milk of adolescents and evaluated their associations with plasma levels and with maternal characteristics (period of lactation, body mass index, age of menarche, and years postmenarche).
Methods
This was a single cross-sectional survey of retinol, carotenoid, and tocopherol composition of milk and plasma of lactating adolescent mothers (n = 72; 30–120 d postpartum) attending public daycare clinics in Rio de Janeiro, Brazil. Milk and plasma components were analyzed by high-performance liquid chromatography.
Results
Nutrient concentrations (micromoles per liter, mean ± SE) in plasma and milk were, respectively, retinol 2.1 ± 0.5 and 0.62 ± 0.44, β-carotene 0.18 ± 0.19 and 0.016 ± 0.017, α-carotene 0.05 ± 0.04 and 0.0035 ± 0.002, lutein plus zeaxanthin 0.15 ± 0.11 and 0.025 ± 0.024, lycopene 0.1 ± 0.11 and 0.016 ± 0.025, α-tocopherol 10.8 ± 5.3 and 2.7 ± 1.8, γ-tocopherol 2.6 ± 2.3 and 0.37 ± 0.15. The milk/plasma molar ratios of retinol and tocopherols were two times higher than those of carotenoids. Significant correlations (P < 0.001) between milk and plasma nutrient levels were observed for β-carotene (r = 0.41), α-carotene (r = 0.60), and lutein plus zeaxanthin (r = 0.57), but not for lycopene, retinol, and tocopherols. Nutrient concentrations in plasma and in milk were not associated with the maternal characteristics investigated.
Conclusion
Concentrations of the nutrients studied, especially retinol and α-tocopherol, in mature milk of lactating adolescents were, in general, lower than in milk of adult lactating women. Milk concentrations were associated with plasma concentrations only for β-carotene, α-carotene, and lutein plus zeaxanthin.
This study was funded by the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), and Fundação Carlos Chagas de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ), Brazil. N.M.F.T. received a research fellowship from the CNPq.
ABSTRACT