RESUMO
Background: Worldwide, an estimated 250 million children <5 y old are vitamin A (VA) deficient. In Mexico, despite ongoing efforts to reduce VA deficiency, it remains an important public health problem; thus, food-based interventions that increase the availability and consumption of provitamin A-rich foods should be considered.Objective: The objectives were to assess the VA equivalence of 2H-labeled Moringa oleifera (MO) leaves and to estimate both total body stores (TBS) of VA and plasma retinol kinetics in young Mexican children.Methods: ß-Carotene was intrinsically labeled by growing MO plants in a 2H2O nutrient solution. Fifteen well-nourished children (17-35 mo old) consumed puréed MO leaves (1 mg ß-carotene) and a reference dose of [13C10]retinyl acetate (1 mg) in oil. Blood (2 samples/child) was collected 10 times (2 or 3 children each time) over 35 d. The bioefficacy of MO leaves was calculated from areas under the composite "super-child" plasma isotope response curves, and MO VA equivalence was estimated through the use of these values; a compartmental model was developed to predict VA TBS and retinol kinetics through the use of composite plasma [13C10]retinol data. TBS were also estimated with isotope dilution.Results: The relative bioefficacy of ß-carotene retinol activity equivalents from MO was 28%; VA equivalence was 3.3:1 by weight (0.56 µmol retinol:1 µmol ß-carotene). Kinetics of plasma retinol indicate more rapid plasma appearance and turnover and more extensive recycling in these children than are observed in adults. Model-predicted mean TBS (823 µmol) was similar to values predicted using a retinol isotope dilution equation applied to data from 3 to 6 d after dosing (mean ± SD: 832 ± 176 µmol; n = 7).Conclusions: The super-child approach can be used to estimate population carotenoid bioefficacy and VA equivalence, VA status, and parameters of retinol metabolism from a composite data set. Our results provide initial estimates of retinol kinetics in well-nourished young children with adequate VA stores and demonstrate that MO leaves may be an important source of VA.
Assuntos
Moringa oleifera/química , Vitamina A/química , Vitamina A/farmacocinética , Composição Corporal , Feminino , Humanos , Lactente , Isótopos , Masculino , México/epidemiologia , Modelos Biológicos , Estado Nutricional , Vitamina A/administração & dosagem , Deficiência de Vitamina A/epidemiologia , Deficiência de Vitamina A/prevenção & controle , beta CarotenoRESUMO
BACKGROUND: Biofortified maize is not only a good vehicle for provitamin A carotenoids for vitamin A deficient populations in developing countries but also a source of vitamin E, tocochromanols and phenolic compounds, which have antioxidant properties. Using high-performance liquid chromatography and a total antioxidant performance assay, the present study analyzed the antioxidant variation and antioxidant activity of 36 provitamin A improved maize hybrids and one common yellow maize hybrid. RESULTS: The ranges of major carotenoids in provitamin A carotenoids biofortified maize were zeaxanthin [1.2-13.2 µg g-1 dry weight (DW)], ß-cryptoxanthin (1.3-8.8 µg g-1 DW) and ß-carotene (1.3-8.0 µg g-1 DW). The ranges of vitamin E compounds identified in provitamin A carotenoids biofortified maize were α-tocopherol (3.4-34.3 µg g-1 DW), γ-tocopherol (5.9-54.4 µg g-1 DW), α-tocotrienol (2.6-19.5 µg g-1 DW) and γ-tocotrienol (45.4 µg g-1 DW). The ranges of phenolic compounds were γ-oryzanol (0.0-0.8 mg g-1 DW), ferulic acid (0.4-3.6 mg g-1 DW) and p-coumaric acid (0.1-0.45 mg g-1 DW). There was significant correlation between α-tocopherol and cis isomers of ß-carotene (P < 0.01). Tocotrienols were correlated with α-tocopherol and γ-oryzanol (P < 0.01). CONCLUSION: Genotype was significant in determining the variation in ß-cryptoxanthin, ß-carotene, α-tocopherol and γ-tocopherol contents (P < 0.01). A genotype × environment interaction was observed for γ-tocopherol content (P < 0.01). © 2016 Society of Chemical Industry.