Studies on the Absorption of Carotene

Abstract

The rate of absorption of carotene is proportional to the dose fed. When fed in cottonseed oil at a level of 350 μg. per gram, 9 μg. were absorbed per 100 sq. cm. per hour; at a level of 3750 μg., 110 μg. were absorbed per hour. These values calculated as I.U. are practically identical with those reported earlier for vitamin A. This occurred in spite of the fact that about two-thirds of the carotene fed in the higher dose was in suspension. The concentration reaches a maximum in the gut wall at 12 hours; considerable amounts still remained in the gut wall after 42 hours, but all had been removed from the lumen of the gut. It is suggested that in the absorption of carotene the transfer through the intestinal wall is the limiting factor since it proceeds more slowly than absorption from the lumen. There is considerable correlation between the amounts of fat and carotene absorbed.