2. Objectives:
To understand definition, meaning and types of minerals
To know the requirement and functions of minerals
3. GLOSSARY:
Mineral- A mineral is an inorganic element occurring in the form of its salt.
Macro minerals - These are required in large amounts at least 100 mg/day e.g.
calcium, phosphorus sodium, chlorine, potassium.
Micro minerals - These are required in small quantities, less than a few mg a day
e.g. iron, sulphur, magnesium.
Trace elements - Their requirement is of the order of a few micrograms e.g.
iodine, fluorine, molybdenum, zinc.
RDA- Recommended Dietary Allowance The levels of intake of essential
nutrients that are judged to be adequate or sufficient to meet the nutrient
requirement of nearly all (97 to 98 percent) healthy individuals in a particular life
stage and gender group.
4. Minerals constitute 3-4 per cent of total body weight.
A mineral is an inorganic element occurring in the form of its salt.
The body contains about 24 minerals, all of which must be provided by the
diet.
These include calcium, phosphorus, potassium, sodium, chlorine,
magnesium, iron, manganese, copper, iodine, cobalt, zinc, aluminum,
arsenic, bromine, fluorine, nickel, chromium, cadmium, selenium, silicon,
vanadium and molybdenum.
These may be present in the body as organic compounds such as
phosphoproteins, phospholipids, haemoglobin, thyroxine, or as inorganic
compounds such as sodium chloride, calcium phosphate and as free irons.
5. Minerals may be classified into three groups.
1. Major minerals or macro minerals - These are required in large amounts
at least 100 mg/day e.g. calcium, phosphorus sodium, chlorine, potassium.
2. Minor minerals - These are required in small quantities, less than a few
mg a day e.g. iron, sulphur, magnesium.
3. Trace elements - Their requirement is of the order of a few micrograms
e.g. iodine, fluorine, molybdenum, zinc.
6. Functions of minerals
1. As structural constituents they serve as:
(i) Building material in hard tissues of the body, bones and teeth and
also give rigidity to these structures.
(ii) Components in soft tissue: muscle protein contains sulphur and
phosphorus, nervous tissue contains phosphorus.
(iii) Components in compounds essential to the functioning of the body
like iodine is present in thyroxine, zinc in insulin, cobalt in vitamin B12,
sulphur in thiamine, iron in haemoglobin and other compounds in tissue
cells. These are part of molecules of hormones and enzymes i.e.metallo-
enzymes.
7. Mineral requirement of various tissues
Tissues Elements especially needed
Bones and teeth Calcium and phosphorus
Hair, nails and skin, soft tissues
Potassium, phosphorus, sulphur,
chlorine
Nervous tissue Phosphorus
Blood
Iron, calcium, sodium, phosphorus,
copper
Glandular secretions
Gastric Chlorine
Intestinal Sodium
Thyroid Iodine
Pancreas Zinc
8. 2. As components in body fluids the minerals have important regulatory
functions:
i. They control water balance in the body by means of osmotic pressure and
by regulating the permeability of cell membrane.
ii. They help to maintain the acid base balance of body fluids.
iii. They also help in regulating the activity of nerves with regard to stimuli
and contraction of muscle. They make possible normal rhythm in heart
beat.
iv. They act as enzyme activators.
v. They regulate cellular oxidation.
9. Mineral requirements of various tissues
To maintain normal exchange of body
fluids (osmosis)
Sodium, potassium, chlorine,
bicarbonate, magnesium.
Contractability of muscles
Balance of calcium with sodium and
potassium.
Clotting of blood Calcium
Oxidative processes Iron, iodine, selenium and manganese
pH of body fluids
Balance between: Basic elements -
sodium, potassium, calcium,
magnesium and iron; acid elements -
phosphorus, sulphur, chlorine.
10. Other trace metals
Other trace metals of significance in human nutrition are selenium, cobalt, silicon,
arsenic, nickel and vanadium.
Selenium is an essential element and along with vitamin E, it is required for maintaining
liver integrity. Selenium deficiency leads to liver necrosis.
An endemic disease of cardiomyopathy in children (Keshan syndrome) is attributed to
low Se in the environment.
Selenium deficiency is also implicated as a risk factor in cancer. Cobalt is important
trace element as it forms part of the vitamin B12. It is also reported that cobalt is required
for optimum utilisation of low doses of iodine.
The possible role of low Co in iodine deficiency disorders (Goitre) is, however not
known.
The nutritional significance of the other trace elements like Si. As, Ni and V in man is
uncertain although their essentiality in animals have been established.
11. References
1. Berdanier, C.D. (2000). Advanced Nutrition: Microntrients, CRC Press, London
2. Nandal, U. (2013). A Handbook of Foods and Nutritional Biochemistry: A Complete
Source Book, Agrobios (India), Jodhpur. ISBN (13):978-81-7754-495-4.
3. Recommended dietary allowances and estimated average requirements, Nutrient
requirements for Indians- (2020), A report of the expert group Indian Council of
Medical Research, National Institute of Nutrition, Hyderabad
4. Srilakshmi, B. (2020). Nutrition Science, New Age International Publishers, Sixth
edition, ISBN 978-93-86418-88-3
5. The Micronutrient Initiative: www.micronutrient.org
