Comparative bioavailability of diet-, oil- and emulsion-based preparations of vitamin a and β-carotene in rat

Abstract

The bioavailability of vitamin A and β-carotene delivered from the diet, from an oily solution or from a lipid emulsion was studied in female and male rats both in moderate and in severe vitamin A-deficient states. Weaning rats were fed a vitamin A-free diet for 3 or 5 weeks and were thereafter supplemented with vitamin A or β-carotene by oral gavage with oil- or emulsion-based solutions or by diet. Vitamin A repletion, as judged by growth rate and by vitamin A accumulation in tissues, was improved when aqueous- preparations of both micronutrients were selected, as compared with other treatments. The vitamin A equivalence of β-carotene ranged from 3.75 to 8.83 when emulsion- and oil- mediated supplementations were respectively achieved. Both vitamin A bioavailabity and vitamin A activity of β-carotene were shown to be related to the vitamin A status of the animal. No sex effect was observed on the measured parameters.