Vitamin A status of young Gambian children: biochemical evaluation and conjunctival impression cytology.

A pilot study was conducted to examine the vitamin A status of Gambian pre-school children by conventional biochemical means and to evaluate the use of conjunctival impression cytology (CIC) in the detection of subclinical vitamin A deficiency. Children were examined on three occasions to coincide with periods of low and high carotene intakes. Plasma retinol and beta-carotene showed highly significant seasonal changes that reflected the seasonal fluctuations in dietary vitamin A. A high prevalence of low plasma retinol levels suggested that vitamin A deficiency may be a public health problem in this community. Underlying infection and vitamin A instability may have contributed to the low plasma retinol levels and given an overestimate of the prevalence of vitamin A deficiency. Seasonal changes in conjunctival impression cytology were not significant. Abnormal CIC results showed no clear association with plasma beta-carotene or retinol.