Zinc is a nutritionally essential mineral needed for catalytic, structural, and regulatory functions in the body.
The RDA (recommended daily allowance) for adult women and men is 8 mg a day and 11 mg a day of zinc, respectively.
Severe zinc deficiency is a rare, genetic or acquired condition. Dietary zinc deficiency, often called marginal zinc deficiency, is quite common in the developing world, affecting an estimated 2 billion people. Zinc deficiency can cause impaired growth and development in children, pregnancy complications, immune dysfunction, and increased susceptibility to infections. Long-term consumption of zinc in excess of the tolerable upper intake level of 40 mg a day for adults can result in copper deficiency.
Zinc bioavailability is relatively high in meat, eggs, and seafood. Zinc is less bioavailable from whole grains and legumes due to the inhibitory effects of phytic acid on absorption of the mineral.
Undernutrition is a form of malnutrition. (Malnutrition also includes overnutrition).
Undernutrition can result from:
inadequate ingestion of nutrients,
loss of nutrients due to diarrhea,
increased nutritional requirements.
Undernutrition progresses in stages: it may develop slowly when it is due to anorexia or very rapidly. First, nutrient levels in blood and tissues change, followed by intracellular changes in biochemical functions and structure. Ultimately, symptoms and signs appear. Diagnosis is by history, physical examination, body composition analysis, and sometimes laboratory tests.
Undernutrition from micronutrient deficiencies, or "hidden hunger", affects over 2 billion people globally and can lead to reduced growth and cognitive development, birth defects, blindness, and overall poor health. Vitamin A deficiency, iron deficiency anaemia and iodine deficiency disorders are among the most common forms of micronutrient malnutrition.