Micronutrients

Micronutrients include all vitamins and minerals. Required in only tiny amounts, they are nonetheless essential for life and needed for a wide range of body functions. Vitamins are either water-soluble (e.g. such as the B complex vitamins and vitamin C) and generally not stored by the body for future needs, or fat-soluble (e.g., vitamins A and D), which can be stored by the body.

Micronutrient deficiency diseases (MDD) are widespread and affect large numbers of people in developing countries. Approximately 2 billion people worldwide suffer from some kind of micronutrient deficiency, causing a wide array of disorders and increasing the risk of death, disease and disability. For example, between 250,000 and 500,000 children a year become blind because of Vitamin A Deficiency (VAD). One quarter of the world’s people suffers from Iodine Deficiency Disorder (IDD), causing not only widespread endemic goitre but also retarding growth, physical and mental development; in its extreme form, this retarded growth is known as cretenism. Anaemia, or Iron Deficiency Anaemia (IDA) – characterised by breathlessness and fatigue - is also prevalent worldwide and, unlike deficiencies in vitamin A and iodine, occurs in both industrialized and developing countries.

Micronutrients are variously distributed in food. Some micronutrients, such as riboflavin, are widely available in a range of foods and hence deficiencies of these are extremely unusual. Deficiencies are more common when a particular micronutrient, such as Vitamin A, is found in only a limited range of food.

An individual’s requirement for different micronutrients depends on age and sex. There are also key periods when micronutrient requirements increase: pregnancy and lactation, early infant and child growth, and during certain illnesses. There is a risk of toxicity with excessive intakes of some micronutrients; a high intake of vitamin A, for example, is especially dangerous for pregnant women as damage to the growing baby can occur.