Just as vitamins are necessary for maintaining various body functions, similarly, minerals and trace elements are required in small amounts for growth and maintenance of health. Various minerals that are required in human body are:

• Calcium
• Carbon
• Chromium
• Cobalt
• Copper
• Fluorine
• Iodine
• Iron
• Magnesium
• Manganese
• Molybdenum
• Selenium
• Silicon
• Sodium
• Phosphorus
• Potassium
• Zinc

Each trace element leads to poisoning if the dose exceeds and leads to deficiency if the intake is less than requirement. These trace elements are also known as micronutrients. The most important ones are discussed here.

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

Copper: Copper is a part of several enzymes in the body. It is an antioxidant and plays an important part in the utilization of iron and formation of red blood cells. Copper deficiency is extremely rare and may occur in formula-fed premature babies. Copper deficiency leads to anemia, recurrent diarrhea and bone problems. Copper deficiency can also occur in a genetic disease such as Menke's disease (leads to hair and brain involvement).
       Excess of copper in the body can occur when milk boiled and stored in brass utensils is consumed. It leads to a liver problem such as Indian Childhood Cirrhosis (ICC). Copper excess can also occur in a genetic disorder - Wilson's disease (characterized by liver, eye and brain problems). Diagnosis of copper deficiency can be established by measuring the blood copper levels. Copper excess can be determined by measuring the copper content in the organ that is involved.

Sources of Copper - Oysters, fish, whole grains, nuts, legumes, milk boiled and stored in brass utensils.

Recommended Daily Allowance (RDA):- 0.05 - 0.1 mg/kg.

Selenium: - It is part of the enzyme system of the body. Deficiency of selenium leads to heart (cardiomyopathy) and muscle involvement (myopathy). It is particularly seen in Keshan province in China where the soil is deficient in selenium. Excess of selenium causes alopecia, abnormal nails, garlic odor to the breath and fatigue.

Sources of selenium - Vegetables, meat, water.

Recommended Daily Allowance (RDA)
< 6 months of age - 10 µg
6-12 months of age - 15 µg
1-6 years of age - 20 µg
7-10 years of age - 30 µg
> 11 years of age - 50-75 µg

Magnesium: - Magnesium is a part of bone and teeth and helps to maintain normal function of muscles and nerves. It has been used in treatment of asthma and persistent pulmonary hypertension (PPHN) in newborns. Deficiency of magnesium leads to spasm of the muscles (tetany). Deficiency can occur in malnutrition, diabetes, chronic kidney disease and in patients with pancreatic problem. Magnesium deficiency can be diagnosed by measuring the magnesium levels in the blood.

Magnesium excess can occur in newborns born to mothers who had received magnesium in pregnancy.

Sources - Cereals, legumes, nuts, milk, meat.

Recommended Daily Allowance: - 40-340 mg.

Last Updated 1-7-2006