Estado nutricional em vitamina A e vitamina E de mulheres no seguimento da lactação

Abstract

In lactation, women need a greater nutritional intake both to replenish nutrients secreted in milk and to ensure adequate nutritional status, as in vitamins A and E, essential for growth, immunity and antioxidant status. Thus, this study aimed to evaluate the nutritional status of vitamin A and vitamin E in over the course of lactation and the relation between usual dietary intake and serum and milk vitamin concentrations. The study was a longitudinal study of 43 lactating women recruited at a public hospital located in Natal-RN, Brazil. The collection of milk, blood and dietary information occurred in three moments: the first between 25 and 74 days postpartum; the second about 30 days after the first and the third 30 days after the second. Retinol and alpha-tocopherol were analyzed by High Performance Liquid Chromatography. Serum alpha-tocopherol <12 μmol/L (517 μg/dL) in serum and <1.05 μmol/L (30 μg/dL) were indicative of low concentrations. Dietary inadequacy was analyzed according to the Estimated Average Requirement (EAR) with intrapersonal variation adjusted by the Multiple Source Method, and the intake was also classified by quartiles of consumption. Serum retinol varied around 1.65 μmol/L over the course of lactation, with 5% of low concentrations only in the first collection, and in the milk 12%, 14% and 12% of low concentrations were identified in the three collections, respectively. Serum alpha-tocopherol decreased in lactation from 30.18 μmol/L in the first collection to 25.49 μmol/L in the third (p=0.008), with an increase in the percentage of deficiency. The concentrations of vitamins in breast milk presented similar values among the samples. Dietary inadequacy of vitamin A and vitamin E was found in 58% and 100% of women, respectively. There was a positive correlation only between serum retinol and vitamin A intake (r=0.403, p=0.007), and higher concentrations of serum retinol were found in women classified as the highest quartile of vitamin A intake (p=0.031). The results found that lactating women are at nutritional risk for vitamin A deficiency and vitamin E, reinforcing the importance of adequate nutrition and monitoring of lactation deficiency.