MINERALS,THEIR FUNCTIONS AND SOURCES.

What are minerals?
Minerals are inorganic substances found in all body fluids and tissues. They occur as salts in food, for example, sodium chloride and they may also be combined with organic compounds as in iron in hemoglobin and sulfur in proteins.

Minerals are not taken for energy.

They are not destroyed in food preparations but they are soluble in water thus there will be loss when cooking liquid is discarded.

Macronutrients

Calcium

Most calcium is found in teeth and bones together with phosphorous and other elements to give rigidity to skeletons.

Functions

1. Facilitate the utilization of vitamin D in the body.

2. Aids in the absorption of vitamin B12.

3. Regulates the transport of materials in and out of the cells together with other elements.

4. Control the transmission of nerve messages.

5. Enables normal contraction of muscles, heart muscles included.

6. It is necessary for blood coagulation.

7. Activate enzymes such as pancreatic lipase.

RDA:

Growing children, pregnant and lactating mothers – 1200 mg

Normal people – 800 mg

Sources:

Milk (fresh, skimmed, dry and butter milk, yogurt and hard cheese). 

Kales, collards and mustard greens.  

Broccoli, cabbage, cauliflowers – fair sources.   

#spinach contains oxalic acid which combines with calcium in the intestines for form an insoluble salt. Calcium salts are not absorbed in the small intestines. However, spinach does not affect the utilization of calcium from other food sources.

Other sources include:

Oranges

Canned salmon

Dried beans

Peas

 Lobster   

Deficiency 

Deficiency is noted after years of inadequacy. 

Bone calcium loss can be detected by an x-ray.

Deficiency leads to rickets in children and osteoporosis in geriatrics.

Periodontal disease, which is the structure of the gums, is an early sign of bone change.

Phosphorous
Functions:

1. Builds bones and teeth.

2. Phospholipids. It regulates the absorption and transport of fats.

3. Have enzymes required for utilization of carbs, fats and proteins.

4. Forms a buffer salt for the regulation of acid base balance.

Sources:

Milk, meat, poultry, egg yolk, fish, nuts and legumes. 

Bones and teeth contain about 60% of Mg.

Functions

1. Enables muscle contraction.

2. Regulates nervous irritability.

3. Activates the enzymes involved in energy metabolism.

Salts of Mg are not absorbed.

RDA: 300-350 mg

Sources

Green leaves, cereals, seafood 

and nuts.

People who suffer from conditions such as diabetic acidosis, severe malabsorption and chronic alcoholism have nervous irritability and tremors which is a sign of magnesium deficiency.

Sulfur

Sulfur is found in proteins specifically methionine, cysteine and cysteine amino acids. It is found in nails, hair, skin and connective tissues.

Sources are protein foods.
Micronutrients

Iron

Amount found in an adult is 3 – 8 mg. iron is found in the red blood cells’ hemoglobin and the muscle’s myoglobin. Hemoglobin is an iron containing compound which picks up oxygen and transports it to other body parts and picks up carbon dioxide and transports it to the lungs. 

Salts of iron are insoluble.

Absorption of iron relies on the body’s needs. 

Heme iron occurring in meats is more efficiently absorbed than non heme found in plants. Vitamin C and the organic substances in fruits improves the absorption of iron. Antacids drugs and caffeine interfere with the absorption of iron. 

RDA

Women: 18 mg

Men: 10mg 

Infants and children: more than the required due to their growth.

Pregnant women: more to cater for their needs.

Sources

Liver and organ meat.

Dark green leafy vegetables.

Legumes and nuts.  

Fruits.  

Supplements are desirable for rapidly growing children and teenagers and pregnant women.

Deficiency leads to anemia which is presented by fatigue and looking pale and supplementation is recommended.

Iodine
Iodine is found in thyroid glands and other cells in traces. Iodine constitutes of two hormones, thyroxine and thyroglobulin.

Functions

1. Regulate energy metabolism.

2. Involved in the synthesis of protein and fats.

3. Facilitate the conversion of carotene to vitamin A.

RDA for men and women is 150 mcg.

Sources

Foods grown in the coast, salt water fish shell fish and iodized salts. 

  

Deficiency 

Deficiency leads to decreased of thyroxine which leads to low energy metabolism. 

At thyroid glands, thyroid hormones enlarge (goiter). It is visible when the neckline enlarge.

In case of untreated goiter in pregnant women, the infant is affected and this leads to growth retardation and dulled mentality.

Zinc

About 2-3 mg of zinc is found in the body.

It is absorbed according to the body’s need. 

Functions 

1. Normal sensitivity to taste.

2. Normal growth and sexual maturity.

3. The synthesis of protein. 

4. It is part of the enzymes involved in the transportation of CO2 to the lungs.

RDA is 15 mg for adults and 10 mg for children.

Sources

Meat, milk, eggs, liver, seafoods , wholegrains, nuts and legumes.  

Deficiency

Deficiency leads to decreased taste sense (hypogeusia) and decreased odor sense (hyposmia), metallic taste, saltiness, bitterness, sourness or sweetness.

Deficiency also leads to sexual retardness and dwarfness. Suppliments are given.

Fluoride

Found in complexes calcium salts in the body.

It reduces tooth decay if water taken has its sufficients amounts.

It also maintains bone structures and there are lesser incidents of osteoporosis.

In deficiency fluoride toothpaste is used and fluoride tablets may be given under a dentist’s supervision.   

Excess of fluoride leads to muttled teeth, ie, teeth have a chalk white appearance which later become discolored.

Reference:

Cohen . N . L (1968). ‘Trade Minerals in Nutrition’.

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