The effect of vitamin A supplementation on tear fluid retinol levels of marginally nourished preschool children.

Vitamin A has been determined in tear fluid and blood plasma of marginally nourished Thai children before and after supplementation with a single, oral dose of 110 mg retinyl palmitate. After two months a significant rise of tear fluid retinol levels of the supplemented group was observed as compared to the non-supplemented group, while after four months no difference could be found. Determination of vitamin A levels in tear fluid may be useful in clinical eye research, with special regard to xerophthalmia.