MINERALS

MINERALS

INTRODUCTION: The importance of minerals in our well-being is emphasized by the fact that iron deficiency anemia is one of the three major health problems in India.

The increase in the number of fractures in the elderly as also the incidence of high blood pressure are also pointers that focus one’s attention on  minerals, calcium and sodium. A liberal intake of calcium, with increased mobility and exposure to sunlight is known to improve the strength of bones and thus reduce their fragility. A reduction intake can be one of the helpful factors in reducing hypertension. Though advertisements for dietary supplements may lead you to believe that these may be the answer to the problem, it is not so. The key is to select foods to meet the body’s mineral needs and to season foods moderately to avoid excess intake of salt.

NATURE AND COMPOSITION: As you may know from your elementary chemistry course, minerals are inorganic substances. So far we have studied nutrients, carbohydrates, fats, proteins and vitamins, which are organic compounds.

Minerals are present in all body tissues and fluids. In bones and teeth the minerals calcium and phosphorous are deposited in protein mineral. Iron is found in blood as a part of the red pigment, hemoglobin. Minerals occur in foods as salts and also in combination with organic substances.

Minerals have two distinct characteristics

• Mineral elements do not provide energy.
• Mineral elements are not destroyed during food preparation.

The mineral elements found in the body from only 4 to 6 per cent of the weight of our adult body. This means that about 2 to 3 kg of our body weight consists of minerals. Of this 90 per cent is accounted for by seven minerals (calcium, phosphorous, potassium, sulphur, sodium, chloride and magnesium). The other minerals are known as trace elements, as these add together to about 10 per cent of the total  mineral content of the body. The mineral composition of the adult body is given in the table.

The largest concentration of minerals is found in the bones and teeth. Minerals are also found in soft tissues such as nerves and muscles and blood and other body fluids.

GENERAL FUNCTIONS OF MINERALS: Some minerals play an important role in the regulation of body functions. These are:

1. Maintenance of acid-base balance.
2. Control of water balance.
3. Contraction of muscles.
4. Normal response of nerves to physiological stimulation.
5. Clotting of blood.

Minerals do not act singly in their function and regulation of body processes, but work with the help of other minerals and organic compounds. A certain concentration of each element must be present for efficient functioning of the body.  

Some of the important tissue formations and processes in which mineral elements function in the unison are discussed below. This will be followed by a discussion of each important mineral element and its specific functions.

Table: Mineral Composition of Adult Human Body

Mineral	Approximate amount in Adult body
	60 kg	50  kg
Major Mineral Elements
Calcium	1030 g	855 g
Phosphorus	645 g	535 g
Potassium	210 g	175 g
Sulfur	150 g	125 g
Sodium	90 g	75 g
Chlorine	90 g	75 g
Magnesium	26 g	21 g
Trace Elements
Iron	3.4 g	2.9 g
Molybdenum	2.6 g	2.1 g
Zinc	1.7 g	1.4 g
Selenium	1.7 g	1.4 g
Fluorine	0.9 g	0.75 g
Copper	130 mg	110 mg
Manganese	130mg	110 mg
Iodine	26 mg	21 mg
Cobalt	4 mg	3.6 mg
Chromium	4 mg	3.6 mg

Most of the calcium, phosphorus and magnesium and small amounts of other mineral elements are deposited in the bones and teeth. Bones and teeth are formed of tough protein material into which minerals are deposited. Most of the bone formation in the fetus occurs in the eighth and ninth months of pregnancy. At birth, the bones are very soft, but the infant has a well formed skeleton. Throughout the growth phases (childhood, adolescence and early adulthood) the bones become long, thick and increase in hardness.

Thus bones form an important part of the body framework. Bones also serve as a reservoir of the component mineral elements. Thus the blood levels of these minerals are maintained by withdrawal of these elements from the bone. The minerals provided in diet replace those withdrawn and thus help to maintain the bone structure. Thus even in bones, there is a continuous process of maintenance and repair of the tissue.

Structural Components of Soft Tissues: Many mineral elements are found in the structural components of soft tissues. These include potassium, Sulfur, phosphorus, iron and others.