Micronutrient deficiency is defined as the sustained insufficient supply of vitamins and minerals needed for growth and development, as well as to maintain optimal health. Since some of these compounds are considered essentials (we need to obtain them from the diet), micronutrient deficiencies are often the result of an inadequate intake. However, it can also be associated to poor intestinal absorption, presence of certain chronic illnesses and elevated requirements. Prevalence Micronutrient deficiencies are considered a public health problem worldwide. For over 30 years it has been estimated that more than two billion people of all ages are affected by this burden, while a recently published study based on individual-level biomarker data estimated that there are 372 million children aged 5 years and younger, and 1.2 billion non-pregnant women of reproductive age with one or more micronutrient deficiencies globally, affecting greatly Asia and sub-Saharan Africa. Women of reproductive age (including pregnant and lactating) as well as children and adolescents are at higher risk of micronutrient deficiencies due to their higher demands. Similarly, the elderly are among the most vulnerable populations, associated to reduced absorption and utilization, as well as poorer diets . Vegans and people reducing animal-source foods in their diets, as recommended by many scientific studies and experts, are also at greater risk of some micronutrient deficiencies if they don't adequately consume supplements or foods substituting animal-sourced micronutrients. The most commonly analyzed micronutrient deficiencies, and therefore the most prevalent, include iodine, iron, zinc, calcium, selenium, fluorine, and vitamins A, B6, B12, B9 and D. Impact Micronutrient deficiencies are associated to short- and long-term consequences as clinical symptoms and signs will manifest in relation to the body stores for the specific micronutrient and the magnitude of the deficiency. Nonetheless, it has been well established that micronutrient deficiencies are major contributors to impaired growth and neurodevelopment, perinatal complications and increased risk of morbidity and mortality. It has also been associated with 10% of all children's deaths, and are therefore of special concern to those involved with child welfare. Early childhood micronutrient deficiency leads to stunted growth and impaired cognitive development, which in turn can translate into reduced work capacity, productivity and overall well-being during adulthood. Deficiencies can constrain physical and (neurocognitive) development and compromise health in various ways. Beyond dangerous health conditions, they can also lead to less clinically notable reductions in energy level, mental clarity and overall capacity. Micronutrients help to