Mineral is naturally occurring chemical compound which is not produced by life process. Food contains varying amount of minerals. The mineral may be present as organic or inorganic salt or may be present with the combination with organic materials such as phospho-protein, hemoglobin, vitamin B2, chlorophyll etc. Minerals like calcium and phosphorous are required in large amount in our diet as they constitute major part of bone. Other minerals like zinc, Cobalt, copper, iodine etc. are required in very small amount ranging from few mg to microgram. However, these minerals should not be neglected in our diet as even they are required in very small amount, their inadequate intake leads to several deficiency diseases.
Functions of minerals in our body
- Necessary for body building, example; bones, teeth, structural part of sort tissue
- Regulation of body process
- Act as electrolyte
- Act as cofactor in enzymes
On the basis of mineral composition in human body and their requirement, minerals are classified into two groups; a) Major minerals and b) Trace elements.
| Major minerals | Composition | Trace elements | Composition | |
| Calcium = | 2.4 % | Iron = | 0.08 % | |
| Phosphorous = | 1.2 % | Fluoride = | 0.005 % | |
| Sulfur = | 0.3 % | Zinc = | 0.005 % | |
| Potassium = | 0.24 % | Copper= | 0.001 % | |
| Sodium = | 0.17 % | Iodine = | < 0.001 % | |
| Chloride = | 0.15 % | Manganese = | < 0.001 % | |
| Magnesium = | 0.05 % | Chromium = | < 0.001 % |
Calcium:
- Most common mineral in human body
- About 99 % of the calcium in body is found in bones and teeth while other 1 % is found in blood and soft tissue.
- Calcium helps in development of strong bones and teeth
- Plays role in normal nerve functioning
- Helps in blood circulation when bleeding
- Deficiency: reduced bone density and increased risk of osteoporosis
- Too much calcium over prolonged period can cause constipation, kidney stone and poor kidney function.
- Food sources: milk and milk products, dark green vegetables, fish with edible bones and tofu made with calcium sulfate, fortified drinks and food such as orange juice, bread, soy milk.
Phosphorous:
- Essential mineral that is required by every cell in the body for normal function.
- Approximately 85 % of body’s phosphorous is found in bone.
- Phosphorous is major component of bones and teeth and makes up part of DNA and RNA.
- Phospholipid are major component of cell membrane.
- Deficiency: Hypophosphatemia characterized by loss of appetite, anemia, muscle weakness, bone pain, rickets in children and osteomalacia in adults.
- Food sources: protein rich foods are best sources. Legumes and nuts rank next. Bread and baked foods also contain phosphorous.
- Recommended daily allowances (RDA): 1000 mg
Iron:
- Iron is essential component of hundreds of protein and enzyme.
- It is essential part of hemoglobin which carries and stores oxygen in body cells.
- Required for electron transport and energy metabolism
- Required for DNA synthesis, reproduction, healing and immune function.
- Deficiency: Anemia, fatigue and infections
- Food sources: meat, poultry, seafood, legumes, nuts and seeds.
- Recommended daily allowances (RDA): 8 mg for male and 18 mg for female.
Iodine:
- It is non-metallic trace element.
- Most of the earth’s iodine is found is in its ocean.
- Iodine is essential component of thyroid hormone and is therefore essential for normal thyroid function.
- Thyroid hormone regulate number of physiological process including growth, development, metabolism and reproductive function.
- Deficiency: Goiter characterized by enlarged thyroid gland and Iodine deficiency disorder (IDD) characterized by growth and developmental abnormalities.
- Food sources: salt water fish, foods grown near coastal area and table salt fortified with iodine.
- Recommended daily allowances (RDA): 150 μ
Sodium chloride:
- This represents a table salt (NaCl) that contribute most of sodium in our diet. Sodium is essential element in life.
- Sodium and chloride are principal ions in the fluid outside cell (extracellular fluid) which includes blood plasma.
- Sodium helps in absorption and transportation of nutrients and regulate movement of body fluid in body, transmit nerve impulse, relax muscle and maintain blood volume and pressure.
- Although scientists agree that a minimal amount of salt intake is required for survival, there are also negative health implication of excessive salt intake.
- Retention of sodium by kidneys increases retention of water, resulting in increased blood volume and blood pressure.
- Deficiency: sodium deficiency is quite unlikely. Except with chronic diarrhea, vomiting or kidney problems. Symptom includes nausea, dizziness and muscle cramps.
- Food sources: processed food account for about 75 % of sodium we eat. Another 25% comes from table salt. Only small amount occurs naturally in food.
About Author
Name : Pratiksha Shrestha
pratiksha.shrestha2001@gmail.com
Ms. Shrestha holds masters degree in food engineering and bioprocess technology from Asian Institute of Technology (AIT) Thailand. She is currently working for Government of Nepal at Department of Food Technology and Quality Control (DFTQC), Kathmandu. She is also a teaching faculty in College of Applied food and Dairy Technology (CAFODAT) affiliated to Purbanchal university, Nepal.