Concentração de alfa-tocoferol no soro e colostro materno de adolescentes e adultas

Abstract

OBJETIVOS: avaliar a concentração de alfa-tocoferol no soro e colostro materno de puérperas adolescentes e adultas e verificar a adequação nutricional de vitamina E do colostro oferecido ao lactente. MÉTODOS: participaram do estudo 72 puérperas, sendo 25 adolescentes e 47 adultas. Foram coletados 5 mL de sangue e 2 mL de colostro em condição de jejum para análise dos níveis de alfa-tocoferol. As amostras foram analisadas por cromatografia líquida de alta eficiência. A adequação nutricional do colostro para a vitamina E foi calculada pelo produto do volume estimado de ingestão de leite com a concentração de alfa-tocoferol no colostro e por comparação direta desse produto com o valor de referência para ingestão do nutriente (4 mg/dia). RESULTADOS: os níveis de alfa-tocoferol no soro de puérperas adolescentes e adultas foram, respectivamente, 30,8±9,8 e 34,1±9,5 μmol/L (média±DP). No colostro, as adolescentes apresentaram concentração de alfa-tocoferol de 32,9±15,8 μmol/L e as adultas de 30,4 ± 18,0 μmol/L, não sendo encontrada diferença significativa entre as concentrações séricas, assim como no colostro dos grupos estudados. CONCLUSÕES: Tanto as puérperas adolescentes quanto as adultas apresentaram um estado nutricional satisfatório de vitamina E refletido no colostro cujos valores foram capazes de suprir o requerimento nutricional do lactente, sugerindo que a idade materna não influencia os níveis de alfa-tocoferol do colostro humano.Abstract PURPOSE: to assess the alpha-tocopherol concentration in the serum and colostrum of adolescent and adult mothers and to determine the nutritional adequacy of vitamin E in the colostrum offered to infants. METHODS: in total, 72 pregnant women participated in the study, 25 adolescents and 47 adults. An amount of 5 mL of blood and 2 mL of colostrum were collected under fasting conditions for the analysis of alpha-tocopherol levels. The samples were analyzed by means of high performance liquid chromatography. Nutritional adequacy of colostrum for vitamin E was calculated as the product of the estimated volume of milk intake by the concentration of alpha-tocopherol in colostrum and by direct comparison of this product with the reference value for nutrient intake (4 mg/day). RESULTS: the levels of alphatocopherol in the serum of adolescents and adults were 30.8±9.8 and 34.1±9.5 μmol/L (mean±SD), respectively, and in colostrum, the adolescents showed a concentration of 32.9±15.8 μmol/L and the adults, a concentration of 30.4±18.0 μmol/L. No significant difference was found between concentrations of alpha-tocopherol in serum or in colostrum between adolescents and adults. CONCLUSIONS: Both adolescents and adult women had a satisfactory vitamin E nutritional status reflected in the colostrum, whose values were able to meet the nutritional requirements of infants, suggesting that the maternal age does not influence the levels of alpha-tocopherol in human colostrum.

Maternal Supplementation With Natural or Synthetic Vitamin E and Its Levels in Human Colostrum

“…These values are acceptable, based on reference values for serum a-TOH concentrations. Similar concentrations were found in other studies (24)(25)(26).…”

“…The lack of correlation between a-TOH in maternal serum with colostrum (r ¼ 0.073, P ¼ 0.440) has been reported (24,27,30,34,40). Dimenstein et al (24) proposed that the absence of correlation between these variables preclude the existence of passive transfer mechanisms during the passage of vitamin E from the mammary gland to the milk, thereby indicating the existence of a transport mechanism in the breast that is independent of plasma concentration. This could be valid because in late pregnancy and at the beginning of lactation, there is a gradual decrease in serum levels of a-TOH, which may explain the considerable increase in a-TOH in colostrum (37,41,42).…”

Vitamin E concentration in human milk and associated factors: a literature review

“…Hence the hypothesis that the milk of adolescent mothers may show lower amounts of alphatocopherol than the milk of adult mothers. 12 In the study by Dimenstein et al, 22 there was no difference (p = 0.50) between alpha-tocopherol levels in the colostrum of Brazilian adolescent and adult mothers ( Table 1). The authors emphasize, however, that the mean age for the adolescent mothers was 17.2 ± 1.4 years, which minimizes the impact of menarche on their nutritional status, as it is the proximity between menarche and pregnancy that potentiates such impact.…”

“…12 Moreover, the pregnant adolescent has to add her own growth requirements to other requirements imposed by pregnancy. 22 Therefore, when pregnancy and subsequent lactation occur in adolescence, nutritional risks associated with this condition may increase. Hence the hypothesis that the milk of adolescent mothers may show lower amounts of alphatocopherol than the milk of adult mothers.…”

The socioeconomic variables influence in the alpha-tocopherol concentration of the maternal serum

“…Gurgel et al 8 found a high prevalence of the deficiency in women attended for the delivery in public maternities when compared to those attended at a private health network. Dimenstein et al 9 found no differences in the alpha-tocopherol serum level according to maternal age; and another study also found no differences in this micronutrient in parturient according to age, parity and gestational weight gain. 10 As it is known in the environment, permeated by material conditions of life and by the access to health services and schooling, it determines characteristic patterns of health and disease.…”