2. Introduction
More than 50 chemical elements are found
in the human body, which are required for
growth, repair and regulation of vital body
functions.
They should be supplied daily as they are
excreted through the kidneys, bowels & the
skin.
Minerals are present in the body as follows:
Components of organic compounds Ex:
haemoglobin contains iron.
As inorganic compounds Ex: calcium
phosphate in the bones & teeth.
3. Definition
“Minerals are inorganic substances
required by the body in small amounts
for a variety of different function”.
Minerals are inorganic substances that
play an important role in a variety of
metabolic reactions, as cofactors.
The minerals form only a small portion of
the total body weight. They form only 7%
of the composition of human body.
4. Classification of minerals
Minerals may be classified into three groups:
1. Major minerals:
Seven minerals are included in this group &
they are required in large amounts of over 100
mg/day.
Ex: calcium, phosphorus, sodium, chlorine,
potassium, magnesium, sulphur .
2. Minor minerals:
These are required in small quantity, less than
100 mg/day. They include iron & manganese.
3. Trace elements:
These are elements required by the body in
quantities of less than a few micrograms per
5. General functions of minerals
• As Constituents of bones and teeth: Ca,
P, Mg
• As Constituents of soft tissues (liver): P
• As soluble salts that give to body fluid
and cell content, their composition and
Stability that are essential for life– Na, K,
Cl, P
• Specific functions:
• Formation of Haemoglobin- Fe
• Formation of thyroxine- Iodine
• Constitution of enzymes and hormones:
Zn in Carbonic Anhydrase and Insulin
7. Calcium
• Macro-mineral
• Constitutes 1.5-2% of the body weight
of an adult human.
• An average adult body contains about
1200 gm of calcium of which >98%
present in bones.
• Calcium in blood: 10 mg/dl
• The developing fetus requires about 30
g of calcium.
8. Calcium absorption
• 20-30% normally absorbed
• Enhance absorption:
• Vitamin-D , High protein in diet , Reduce
absorption , Oxalates , Phytates , Fatty
acids ,Fibers in diet.
• Retention:10-20% but depends on diet
and age
Dietary calcium which is not absorbed in
the intestines is excreted in the urine.
9. Calcium-Sources
• Milk and milk Products
• Cow milk- 1200mg
• Human Milk- 300mg
• Egg and Fish
• Cheapest dietary sources:
• Green leafy vegetables (presence of
oxalates)
• Millets
• Cereals
• Water- 200mg/day
10. Calcium requirement
ICMR recommended dietary allowance
for calcium
Age group RDA for calcium mg/day
Infant 0-12 months 500
Children 1-9 years 400
Children 10-18 years 600
Adolescent 16-18 years 500
Adult 400
Pregnant women 1000
Lactating women 1000
11. Functions
• Bone formation
• Teeth Formation: formation of dentin and
enamel
• Physiological Process:
• Essential for the clotting of blood as it is
required for prothrombin activation
• Regulates the permeability of the capillary
walls and ion transport across the cell
membranes
• Contraction of the heart and skeletal
muscle
• Regulates the excitability of the nerve
fibres
• Acts as an activator for enzymes such as
rennin and pancreatic lipase
12. Deficiency of calcium
• Effects in Adults:
• Osteoporosis
• Fractures of brittle bone by miner
accidents • Effects in Children:
• Decreased rate of growth
• Loss of Calcium from Bone leading to
development of Osteoporosis
• Hyperplasia of parathyroid gland
• Hyper-irritability and tetany leading to
death
13. Cont…
HypoCalcemia-
• Motor nerves become over susceptible
to stimuli
HyperCalcemia- • Common in 5-8 months
children
• May occur because of excess Vit-D
• Symptoms: loss of appetite, Vomiting
and wasting
• Treated by diet with low Calcium
15. Phosphorus
Phosphorus is found in every cell of
the human body. A major part of this
(about 80% of the total) is present in
combination with calcium in the bones
and teeth.
About 10% is combined with proteins,
lipids and carbohydrates.
The remaining 10% is widely
distributed in various chemical
compounds.
16. Cont…
Exist in 2 forms:
As Inorganic salts :
• Calcium Phosphates in Bones and teeth
• Phosphates of Na and K in soft tissues
In combination with organic
compounds
• Phospholipids-lecithin, Cephalin
• Nucleoproteins and Nucleic Acids
• Creatine Phosphates-ATP, ADP.
17. Phosphorus Absorption &
Storage
Phosphorus is absorbed in the small
intestine as inorganic phosphate. Organic
phosphorous is hydrolyzed to inorganic
phosphate before absorption.
Phosphorus present in animal food such
as milk, meat & eggs is absorbed to a
greater extent than that present in cereals
& legumes. It is excreted through
kidneys. 10-40% of phosphorus is
retained in the body. Its retention
depends on the quantity ingested,
calcium content of the diet & vitamin D
intake. The inorganic phosphorus level in
