Nutritional deficiencies, also referred to as malnutrition, are widely spread in developing countries. The consequences are utterly devastating. For example, malnourished children compared to their well-nourished counterparts have impaired growth, more severe illnesses, an increased mortality risk or a lower performance at school. The most frequent forms of malnutrition are protein-energymalnutrition (PEM) and micronutrient deficiencies, such as Vitamin A, iron and iodine deficiency. Other micronutrients of concern are B Vitamins, Vitamin C and zinc. Often micronutrient deficiencies are combined. For example, in northern Morocco the prevalence of Vitamin A deficiency in children is as high as 50%. Many of those children are iodine deficient too, indicated by a goiter rate of more than 80%. Similarly, there is a high prevalence of iron deficiency in Moroccan children, with 35-40% of children affected.
Vitamin A is a fat-soluble vitamin. Vitamin A plays a pivotal role in reproduction and supports growth and immune function. It is important for the skin, the integrity of mucosal surfaces and normal wound healing. Vitamin A is also essential for visual function as a component of visual purple. The liver can often compensate for considerable daily and seasonal variations in Vitamin A supply. However, the liver stores of young children and mothers are often very low.
Vitamin A deficiency (VAD) is the most common form of vitamin deficiency in the world. It is estimated that VAD exists in more than 70 developing countries. VAD primarily occurs in infants and young children. VAD is also increasingly recognized in women, and may account for most maternal deaths. Initial symptoms of VAD include increased sensitivity to light, dry eyes (xerophthalmia) and impaired adaptation to the dark (nightblindness). In advanced stages, ulcerations of the conjunctiva occur and eventually lead to complete blindness, particularly in small children.