Evaluation of rose bengal staining test and rapid dark-adaptation test for the field assessment of vitamin A status of preschool children in Southern Brazil.

The objective of this study was to evaluate two of several methods presently available for assessing vitamin A status of marginally malnourished preschool children of socioeconomically deprived families in Southern Brazil. The rose bengal staining test and rapid dark-adaptation test were evaluated by comparing their results with conventional methods that require estimation of dietary intake of vitamin A equivalents and determination of plasma levels of retinol before and after an oral supplementation of 200 000 IU vitamin A. Results indicate that neither test evaluated is useful by itself. There was no significant correlation between the results of the rose bengal staining test and the plasma levels of retinol. Also, no significant correlation was observed between the rapid dark-adaptation time and the vitamin A status of the preschool children as determined by plasma-retinol levels before and after vitamin A supplementation.