COMPARISON OF SERUM RETINOL CONCENTRATION BETWEEN HUMAN AND DIFFERENTSPECIES OF NORMO AND HYPERCHOLESTEROLEMIC NONHUMAN-PRIMATES FED SEMI-PURIFIED DIETS WITH DEFINED AMOUNTS OF VITAMIN-A

1. Serum retinol and total cholesterol concentrations were determined in several species of nonhuman primates fed semipurified diets. Two sp ecies of Old World and three species of New World nonhuman primates we re examined. 2. Retinol levels were significantly lower (up to four-fo ld) in the serum of the smaller New World than the larger Old World an imals and the difference could not be explained by differences in diet ary make-up. 3. Cholesterol levers were not different between the grou ps but differed within a species when type of dietary fat was altered. 4. Differences in circulating levers of retinol may reflect differenc es in levels of retinol binding protein between the groups.