Evidence of early childhood defects due to prenatal over-exposure to vitamin A : a case study

Abstract

One of the important nutrients during pregnancy is vitamin A or related compounds called retinoids. Although it is well-known that vitamin A deficiency may be detrimental to foetal development, overdosage of retinoids might cause developmental defects, particularly affecting the central nervous system development of the foetus, causing hindbrain dysfunction which may be associated with cognitive impairment. Here we discuss a case study based on a 7 years 11 months grade one girl who was prenatally exposed to high dosages of vitamin A. The baby reached her developmental milestones later than expected, she never crawled properly, and she experienced difficulty in maintaining her balance. She suffers from lateral nystagmus and slight strabismus, resulting in diplopia, while tactile defensiveness was also reported. In the current study, the Senior South African Individual Scale - Revised (SSAIS-R) as well as the Quick Neurological Screening Test - Revised Edition (QNST) were performed and this suggested that the hindbrain, the cerebellum and the hippocampus, including related pathways to the parieto-temporo-occipital region, were affected. Furthermore, sensory and motor impairment as well as inaccuracy of movements, poor timing and rhythm, compromised spatial perception, and associated somatoperceptual impairment were demonstrated. We conclude that results from the SSAIS-R and the QNST both indicate cognitive impairment that can be linked back to hindbrain impairment and that cognitive impairment due to vitamin A overdose can be assessed using educational testing.