Efeito da suplementação com vitamina A sobre a concentração de retinol no colostro de mulheres atendidas em uma maternidade pública

Abstract

OBJECTIVE The aim was to evaluate the effect of supplementary vitamin A upon the colostrum retinol levels in puerperal women cared for at a public maternity hospital in Natal, RN, Brazil. Analysis was conducted on the influence of the colostrum retinol and the maternal nutritional condition as response to supplementation. METHODS For analysis of serum retinol 5 ml of fasting blood and two samples of milk were collected before and 24 hours after supplementation. A questionnaire was used to define the frequency of previous vitamin A intake. High Efficiency Liquid Chromatography was used to analyze the retinol. RESULTS Vitamin A intake was 1492.4 +/- 1264 microg RAE/day and 23% probably had an inadequate intake. At the beginning of supplementation, 0 hour, and at 24 hours, the control and supplemented groups presented serum retinol concentrations of 1.3 +/- 0.4 and 1.4 +/- 0.4 micromol/L (7% deficiency) and 3.5 +/- 1.7 micromol/L and 3.3 +/- 1.8 micromol/L (p>0.05) at 0 hour colostrum, respectively. Retinol in the 24 hours milk of the supplemented group increased from of 3.6 +/- 1.9 and 6.8 +/- 2.6 micromol/L (p<0.0001), respectively. Women with deficient levels of retinol in the colostrum at 0 hour(<2.04 mol/L) transferred more retinol to the colostrum at 24 hours milk than those with adequate levels (an increase of 326.1% and 86.5%, respectively). CONCLUSION The megadose of vitamin A was efficient in the first 24 hours after supplementation. The supplementation response was influenced by the basal levels of retinol in the colostrum. Parturient women with low initial levels of retinol transferred more retinol to the milk, after the megadose, than nursing women with sufficient levels. This possibly confirms the action of the Vitamin A transfer mechanisms proposed by the mammary gland.