THE EFFECT OF THE USE OF MINERAL OILUPON THE ABSORPTION OF VITAMIN A* By

THE use of mineral oil as a laxative has been reported to interfere with the absorption of vitamin A. If this is true, its use should be restricted. Since it is one of the most commonly used laxatives, its effect deserves further study in order to determine whether it is a valuable or pernicious substance. Dutcher, Ely and Honeywell (1927) fed rats limited amounts of vitamin A and varying amounts of mineral oil and found that growth of rats was prevented when the oil was added to the diet. They are of the opinion, therefore, that mineral oil acts as a solvent for vitamin A, carrying it out of the system. Burrows and Farr (1927) also have reported losses of vitamin A when mineral oil was added to an adequate diet and believe that mineral oil depletes the system of its store of vitamin A. Mellanby (1928) on the other hand believes the effect of mineral oil to be due to inter ference with the absorption of bile salts. He has shown that bile salts form a stable emulsion with the mineral oil and are, therefore, lost to the system and digestion is impaired when bile salts are not absorbed. He believes that the bile salts act as a hormone for pancreatic secretion or are the vehicles by which secretin is carried through the intestinal wall. In either case there would be little fat digestion or absorption. This is an interesting hypothesis, but Gage and Fish (1924) found in their studies of blood fat that, while there was no evidence of mineral oil absorption from the intestine, butter taken with the mineral oil increased the fa