Abstract
Serum vit. A levels were detd. in normal adults who received a test dose of 100,000 u[mu] synthetic vit. A palmitate in corn oil. Falsely flat tolerance curves were obtained in 5 of 16 subjects studied for 8 hrs. when fasting. These subjects showed normal @@@ absorptive curves when a meal was fed 2 hrs. after admn. of the test dose. Sham feeding at 2 hrs. also produced normal curves. Three totally-gastrectomized subjects showed the same normal response to eating. Eating accelerated the rise in serum vit. A when the test dose was administered intraduodenally; atropine intramusc. slowed the rate but not the max. serum concn. attained. Exclusion of pancreatic and biliary secretions from upper jejunum did not prevent response to eating when test dose was administered via tube into this loop.