Critical Levels of Mineral Oil Affecting the Absorption of Vitamin A

Abstract

Summary In order to evaluate the effect of the administration of mineral oil in different doses and in different modes on the absorption of vitamin A and carotene, the plasma vitamin A level and carotenoid level was followed during experimental periods of four weeks on a borderline vitamin A diet on which the plasma vitamin A level remains fairly constant. The study was based on 66 patients for 115 periods. 1.On a diet containing a vitamin A potency of 2500 I.U. (given mostly in the form of carotene) the average of the vitamin A levels remained constant, whereas on diets containing 1500 I.U. a significant drop of the average levels was noted, on diets containing 3000 I.U. the level, if anything, showed a tendency to rise. 2.On a 2500 I.U. vitamin A potency diet, administration of 30 cc. of mineral oil mixed into the noon meal (6.8%) led to a drop of the plasma vitamin A level whereas 5 cc. (1.1%) were without effect. 3.Ten cc. of mineral oil t.i.d. mixed into breakfast, lunch and dinner was associated with a marked drop of the vitamin A level. Five cc. given similarly was associated with a moderate drop, whereas 2.5 cc. was not associated with any decrease. 4.On a diet containing 3000 I.U. of vitamin A, administration of 30 cc. of mineral oil with the meal also reduced the plasma vitamin A level. 5.Thirty cc. of mineral oil, the usual therapeutic dose given at bedtime independent of meals, was without effect. 6.The previously reported interference with absorption of vitamin A or carotene by administration of mineral oil close to mealtimes has been confirmed. However, the presence of a critical level has been demonstrated (2.5 cc. t.i.d.) below which this interference appears insignificant.