Impact of micronutrient deficiencies on growth: the stunting syndrome.
Stunting is a process that can affect the development of a child from the early stages of conception and until the third or fourth year of life, when the nutrition of the mother and the child are essential determinants of growth. Failure to meet micronutrient requirements, a challenging environment and the inadequate provision of care, are all factors responsible for this condition that affects almost 200 million children under 5 years of age. The timing and duration of the nutritional insult leads to different physiological consequences. Growth retardation is however just one feature of a complex syndrome including developmental delay, impaired immune function, reduced cognitive function and metabolic disturbances leading to increased prospective risk of obesity and hypertension. Prevention is possible by undertaking interventions at all stages of the life cycle, and mainly involves the promotion of exclusive breast-feeding until the age of 6 months and the provision of complementary foods and family foods with adequate micronutrient density. Treatment is possible, at least until the age of 5, and can lead to reversal of all the symptoms, although further research is required to clarify whether accelerating growth velocity might also lead to an increased risk of metabolic syndrome.