Chapter 1
Micronutrients as "mighty nutrients" to reduce the burden of hidden hungerThe global community is becoming increasingly concerned about providing healthy and sustainable diets for all people living on this planet. The 3 rd Millennium Development Goal (MDG), which is aimed at 'ensuring healthy lives and promoting well-being for all at all ages, emphasised that the regular intake of a healthy diet, i.e. a diet that meet the requirements of the human body, prevents several diet-related non-communicable diseases (NCDs) and micronutrient deficiencies (WHO, 2020). Micronutrient deficiency, also known as hidden hunger, is often unnoticed for a long time in individuals before the symptoms become apparent, thus the term 'hidden hunger'. It is a kind of undernutrition that arises when consumption and absorption of micronutrients (vitamins and minerals) such as vitamin A, iron and zinc are inadequate in sustaining good health and development (Gani et al., 2019). It ravages most low-and-middleincome countries (LMICs) worldwide due to the low consumption of micronutrient-rich diets, heavy reliance on mainly starchy staple diets and the lack of diversity in the people's diet (von Grebmer et al., 2014). As shown in Fig. 1.1, unhealthy diets, hidden hunger, and NCDs are interwoven and often closely linked (Branca et al., 2019). About 2 billion people in developing countries, primarily children and women of reproductive age, are currently affected by hidden hunger, especially vitamin A, iron and zinc deficiencies (La Frano et al., 2014).Vitamin A deficiency is manifested by mild to acute systemic effects on innate and acquired host's resistance mechanisms to infection, an increased burden of infectious morbidity, mild to severe (blinding) stages of xerophthalmia, and an increased risk of mortality (Huang et al., 2018). The earliest ocular manifestation of vitamin A deficiency is night-blindness and it is particularly prevalent in pregnant mothers. An inadequate diet in preformed or carotenoid precursors of vitamin A is the underlying cause of the deficiency, and adequate consumption of vitamin A-rich food may help reduce the incidence of the deficiency provided there are no underlying diseases or infections affecting absorption of vitamin A in the host. Since the human body cannot synthesise vitamin A, it must be obtained from the diet or through supplemental sources (Debelo et al., 2017). Dietary vitamin A is consumed as either carotenoid from fruits and vegetables or retinoids from animal products. Thus, the World Health Organisation guidelines recommend a daily vitamin A intake of 400 mg RE for children aged 1-3 years, 500 mg RE for adult women, and 600 mg RE for adult men.Iron deficiency also results in modifications of the human metabolic functions that could affect brain functioning, such as neurotransmitter metabolism, protein synthesis and General introduction Chapter 1 11 12 organogenesis (Soetan et al., 2010). There are two forms of iron: haem and non-haem.Haem iron is found in animal sources, whereas non-ha...