PLASMA-CONCENTRATIONS OF BETA-CAROTENE, VITAMIN-A AND VITAMIN-E AFTERBETA-CAROTENE AND VITAMIN-E INTAKE

We have studied the metabolism (absorption) of beta-carotene and vitam in E by assigning eleven volunteers to receive daily two capsules of O ENOBIOL, each containing 15 mg of beta-carotene and 15 mg of vitamin E , over 60 days. The beta-carotene, vitamin E and vitamin A plasma leve ls were then determined using new methods developed in our laboratory. After two months, the actively treated group's median beta-carotene a nd vitamin E levels were significantly higher than those of a control group. However, no significant change between treated and control grou ps in the mean of vitamin A (retinol) plasma levels were observed. Tre atment with beta-carotene, a vitamin A precursor, does not significant ly modify the vitamin A levels. This conclusion had already been obser ved and it is assumed that a plasma level of beta-carotene equal or hi gher than 0.3 mg/L reflects a nutritional intake of provitamins suffic ient to support homeostasis of retinol (Brubacher et al., 1982).