ABSTRACT
At least 44 known nutrients are required by humans consistently and in adequate amounts to live healthily (Bouis and Welch 2010). Next to macronutrients carbohydrates, protein, fatty acids and macrominerals, many micronutrients, essential trace minerals and vitamins are indispensable to human health. Deficiencies in Fe (iron), Zn (zinc), vitamin A and I (iodine) are noted as serious health concerns worldwide (Bohra et al. 2015). Fe deficiency is the most prevalent MNM in the world, it is estimated that over 30% of the global population suffers from Fe deficiency (Tulchinsky 2010). Iron-deficiency anaemia (IDA) affects >50% of women and preschool children in developing countries, and is responsible for as much as 20% of deaths among women during childbirth. Furthermore, IDA impairs physical and mental development in childhood and adolescence (Pfeiffer and McClafferty 2007) and renders the affected more vulnerable to a range of infectious diseases including malaria (Tulchinsky 2010). Zinc deficiency (ZD) is also globally widespread, but less information is available due to less testing for this nutrient (Dwivedi et al. 2012). ZD is a major cause of child and infant stunting, affecting small children and adolescents (FAO/WHO 1998; Bouis 2003). ZD also increases morbidity of a number of infectious diseases and possibly malaria (Allen et al. 2006). Vitamin A deficiency (VAD) is associated with blindness and higher morbidity and mortality of diseases (FAO/WHO 1998). It is estimated that VAD affects 140 million preschool children and over 7 million pregnant women every year, representing the most severe vitamin deficiency in human nutrition. Iodine deficiencies can lead to goitre, hypothyroidism and cognitive impairment among other symptoms. A lack of iodine in soil and basic foods is widespread globally, two billion individuals are estimated to have insufficient iodine intake, mainly in South Asia and sub-Saharan Africa (Tulchinsky 2010). Major efforts are directed towards alleviating MNM, to supply a healthy diet for the whole population. Agricultural systems have to be formed that not only provide enough calories to meet the energy needs of the poor but also deliver all the essential nutrients needed for adequate nutritional health.
