Vitamin A supplementation: A case of not seeing the wood for the trees?

Abstract

In over 70 countries in the developing world, vitamin A deficiency (VAD) continues to be an important public health problem. It affects about 127 million preschool-aged children, of whom 1.2 - 3 million die unnecessarily and 4.4 million suffer from xerophthalmia that may lead to blindness.1 Other effects of VAD may be subclinical (impaired iron mobilisation, disturbed cellular differentiation, depressed immune response) or clinical (increased infectious morbidity, growth retardation, anaemia).