EFFECT OF SUBADEQUATE MATERNAL VITAMIN-A STATUS ON PLACENTAL-TRANSFEROF RETINOL AND BETA-CAROTENE TO THE HUMAN FETUS

The placental transfer of retinol and beta-carotene was assessed based on maternal serum, cord serum and placental levels at term parturitio n in women with adequate (n = 15; serum retinol > 20 mu g/dl) and suba dequate (n = 16; serum retinol less than or equal to 20 mu g/dl) vitam in-A status. There was no difference in retinol and beta-carotene leve ls in placenta and cord serum between these groups. However, differenc es in the relation of maternal, placental and cord blood components we re observed between women with adequate and subadequate vitamin-A stat us. In women with subadequate status, circulating fetal retinol levels correlated with placental retinol levels, and maternal serum beta-car otene correlated with placental retinol. Within this group, maternal s erum beta-carotene and cord serum retinol correlated significantly in women with serum retinol levels lower than 15 yg/dl. These results sug gest that beta-carotene may be a precursor of retinol in. placenta and that this conversion may depend on the nutritional status of the moth er, being particularly effective in a more depleted state.