Measurement of fat absorption using [3H]glycerol triether and [14C]glycerol trioleate in man.

A direct test of lipid absorption has been developed using [3H]glycerol triether as a lipid marker and [14C]glycerol trioleate as the test lipid. Percentage absorption of triolein is calculated from the isotope ratio ingested and excreted in faeces. The test is independent of a complete faecal collection, reproducible and shows little day to day variation. Absorption in 25 normal subjects ranged from 96.4--100% (mean 98.6, S.D. +/- 1.15). In 24 patients with known pancreatic or small intestinal disease and steatorrhoea absorption ranged from 0.01% to 89.9%. The test has also been assessed by comparison with a standard Lundh test and faecal fat estimation in 34 patients.