Unraveling the Contradictions of Vitamin A and Infectious Diseases in Children

Abstract

In this age of modern medicine we have become increasingly dependent on sophisticated antimicrobial drugs and vaccines so it is easy to lose sight of the fact that simple interventions can effectively contribute to the treatment or prevention of infectious diseases. Within the past 100 years there have been several notable examples of such simple interventions including oral rehydration therapy for acute diarrheal illness directly observed therapy for tuberculosis and the use of vitamin A in child survival programs. Naturally occurring vitamin A is obtained from several dietary animal sources including liver oils eggs and dairy products as well as from carotenoids in green leafy and orange vegetables and fruits. In premodern times when foods were not fortified with vitamin A deficiencies of this micronutrient were extremely common especially among persons living in poverty. Modern scientific investigation of vitamin A began at the start of the 20th century with the observation of an association between xeropthalmia (or night blindness) and severe malnutrition. As far back as the time of Hippocrates this very obvious and debilitating condition was observed to be reversible by consuming specific foods such as animal liver codliver oil or butter. (excerpt)