1. Six pre-school children with normal intestinal absorption were given 100000 μg of retinyl palmitate and 14·4 μCi of [11,12-3H]retinyl acetate.
2. The absorption, excretion and retention of the label were determined.
3. The children retained 23–54% of the label.
4. The inefficacy of the massive dose as a prophylaxis against deficiency is discussed.