Zinc: Zinc deficiency was first described in the Middle East. Zinc deficiency is commonly seen in conditions such as chronic diarrhea, nephrotic syndrome, cirrhosis, with chelators as in Thalassemia, patients on total parenteral nutrition (TPN), burns and hemolytic anemia. Zinc deficiency can also occur due to eating a predominantly cereal diet or when body requirements are increased as in pregnant women. Zinc in the body can decrease in patients eating mud and clay (pica).

Clinical features of zinc deficiency: Early features of zinc deficiency include loss of appetite, impaired taste and poor healing of wounds. It can also lead to anemia, night blindness, enlargement of liver, loss of hair and tendency towards infection due to impaired immunity. In older boys, impotency may be seen. Zinc deficiency in pregnant women can lead to growth retardation in the baby.

The classical presentation of zinc deficiency is "acrodermatitis enteropathica". This is a genetic disease due to failure to absorb zinc from the intestines. It leads to loss of hair, poor appetite, diarrhea and typical skin ulcerations over the buttocks and genitals.

Diagnosis can be established by measuring zinc levels in blood and urine.

Treatment - Patients with zinc deficiency should eat a diet rich in zinc such as meat, eggs, nuts, cheese, and grains. Zinc can also be applied as a cream over ulcers, wounds, burns and pimples to fasten healing. Zinc can be given in the dose of 20-40 mg/day for treatment of acrodermatitis enteropathica. Zinc is also recommended in the treatment of persistent diarrhea and Wilson's disease (a genetic problem that leads to accumulation of copper in liver and brain. Zinc helps to excrete this extra copper in the urine).

Zinc toxicity - Zinc toxicity can lead to nausea, vomiting, diarrhea, anemia, and neurological problems. It occurs due to food cooked in galvanized utensils.

Recommended Daily Allowance (RDA)
0 - 1 year - 5 mg
1-10 years - 10 mg
> 10 years - 15 mg