UNIT -1
IMPORTANCE OF FOOD AND
NUTRITION INRELATION TO
HUMAN BEINGS
&
NUTRITIONAL ELEMENTS
General objective
►After completion of the Unit-1, the students should
be able to recognize the importance of food and
nutrition and the functions which food contributes
to the body.
Specific Objectives:
►After completion of the class students should be able to:
►Define food.
►Define Nutrition.
►Define Nutrient.
►Define Calorie.
►Recognize the functions of food and nutrition in relation to
human being.
Definitions
►Nutrition: It is defined as the science of food and its
relationship to health.
►Nutrients: Defined as the food or other substance
that provides energy or building material for the
survival and growth of a living organism.
►Food: Anything which taken in to the body, serves
to nourish or build up tissues or to supply body heat.
►Calories: The power of the animal body of
developing and maintaining heat.
►Balanced Diet: This is the diet which provides
adequate amount of all nutrients, not too much or
not too little.
Functions of food and Nutrition in relation to the
human being
► Provide body fluid and to help regulate body
temperature.
► As fuel for energy for body heat and work.
► For growth and repair.
► For developing body tissues.
► For metabolic processes and protection.
► To form a vehicle for other nutrients, add bulk to the
diet.
► Provide a habitat for bacterial flora and assist
proper elimination of refuse.
Factors contributing to increased
food intake
 Advertising of high – calorie foods targeted at children
and adults
 Vending machine selling high-sugar drinks and highfat snacks
 Greater number of meals eaten in restaurants
 Continuous snacking
Indications of Food and Nutrition Signals
The nutritional health of an individual is referred to as his
or her nutritional status and describes how well nutrient
needs are being met.
Measurements used to evaluate
Nutritional status
►It is related to
►Dietary intake
 Where and when food is eaten
 Use of dietary supplement
 Food sources
 Special diet if any
 Cooking facilities
► Biochemical measurements

Blood vitamin levels

Blood Protein levels

Blood Lipid Levels
► Anthropometric Measurements

Body weight or height (Body Mass index)

Skin fold Thickness

Waist circumference
► Clinical Measures

Skin

Hair

Eyes
Importance of culture and religion
in food
 Judaism: Meat:- Pork is forbidden, but other forms of poultry
are allowed. Meat must be rigidly cleansed of all blood.
 Meat and milk may not be combined. Orthodox
homes maintain two sets of dishes and cooking
utensils – one for serving meat and the other for meals
containing dairy products.
 Fish with fins and scales are allowed in the diet, but no
shell fish is allowed.
Islamic food culture
 Muslim dietary laws are derived from Islamic
teachings I the Koran.
 Alchohol is strictly forbidden
 Pork is strictly forbidden.
 Chinese:
 Chinese cooks believe that refrigeration diminishes
natural flavors, so they select the freshest foods
available
NUTRITIONAL ELEMENTS
CARBOHYDRATE
►General objective
►After completion of the Unit-2, the students should
be able to understand about the nutritional element
– carbohydrate.
►Specific Objectives:
►After completion of the class students should be
able to:
►Recognize the functions of carbohydrate.
►Identify the food sources of carbohydrate.
►Recognize the recommended amount of dietary
carbohydrates.
►Discuss the classification of carbohydrate.
CARBOHYDRATES
►Carbohydrates are the body's most preferred source of
energy. They make up, by far, the largest volume (60%)
of our daily food.
They are taken in the form of all foods made up of grain
flour, cereals, pasta, potatoes and other vegetables, and
also in the form of sugars contained in fruits, syrups,
honey and candy, as well as in the pure crystalline form
of our familiar table "sugar".
Functions of Carbohydrate:
►Keeping and regulating body temperature.
►Supply energy for all cells in the body.
►As a part in mothers milk content.
►As a part in glycoprotein.
►To complete oxidation of fats.
►Protect protein from breakdown in the body.
►Very essential for nervous system.
Classification of carbohydrate
►
The carbohydrate is a class of chemical compound
composed of carbon, hydrogen and oxygen.
►MONOSACCHARIDE
►DISACCHARIDES
►POLYSACCHARIDES
1 Monosaccharide
The simplest carbohydrates are the monosaccharide,
or simple sugars. These sugars can pass through the
wall of the alimentary tract without being changed
by the digestive enzymes. The three most common
are glucose, fructose and galactose.
a) Glucose, sometimes also called dextrose, is present
in fruit, sweet potatoes, onions and other plant
substances. Glucose is oxidized to produce energy,
heat and carbon dioxide, which is exhaled in
breathing.
b) Fructose is present in honey and some fruit juices.
c) Galactose is a monosaccharide that is formed,
along with glucose, when the milk sugar lactose is
broken down by the digestive enzymes.
2 Disaccharides
The disaccharides, composed of simple sugars, need to
be converted by the body into monosaccharide
before they can be absorbed from the alimentary
tract. Examples of disaccharides are sucrose,
lactose and maltose.
a) Sucrose is the scientific name for table sugar (the
kind that is used, for example, to sweeten tea). It is
most commonly produced from sugar cane but is
also produced from beets. Sucrose is also present in
carrots and pineapple.
b) Lactose is the disaccharide present in human and
animal milk. It is much less sweet than sucrose.
c) Maltose is found in germinating seeds.
3 Polysaccharides
The polysaccharides are chemically the most complicated
carbohydrates. They tend to be insoluble in water, and only
some can be used by human beings to produce energy.
Examples of polysaccharides are starch, glycogen and
cellulose.
a) Starch is an important source of energy for humans. It
occurs in cereal grains as well as in root foods such as
potatoes . Starch is liberated during cooking when the starch
granules rupture because of heating.
b) Glycogen is made in the human body and is sometimes
known as animal starch. It is formed from monosaccharide
produced by the digestion of dietary starch.
c) Cellulose is sometimes called unavailable carbohydrates
because humans cannot digest them.
IMPORTANT SOURCES OF
CARBOHYDRATES
Most carbohydrates - Foods of plant origin.
Lactose - in milk.
Sugar - Fruit, fruit juice, table sugar, honey, soft drinks,
and other sweets
Starch - Bread, cereal, potatoes, pasta, rice, and legumes
(dried peas and beans)
Fiber - Whole-grain foods, raw vegetables and fruit
(especially the seeds and skins), legumes, nuts, seeds
and popcorn
Utilization: (the supply of energy to the tissue)
►The routes along which dietary carbohydrates may
pass before utilization in the tissues as a source of
energy shows in the figure.
►Intake -------------Alimentary canal
►Transport--------Blood & lymph
►Storage ---------Liver, muscles
►
adipose tissue
►Transport ------Blood
►Utilization------Tissue
Recommended amount of dietary
Carbohydrates
The recommended dietary allowance (RDA) for
carbohydrate is same for all persons above one year of
age. Children, adolescents and adults should take
in a minimum of 130 g/day.
NUTRITIONAL ELEMENTS
PROTEINS & FATS
►General objective
After completion of the Unit-3, the students should be able to
understand about the nutritional elements – Proteins and
Fats.
►Specific Objectives:
After completion of the class students should be able to:
 Recognize the functions of Protein.
 Recognize essential and non essential amino acids.
 Discuss the food sources of Protein.
 Identify the dietary requirement of protein.
 Understand functions of fats.
 Recognize the types of fat.
 Identify the food sources of fats.
 Understand the daily requirement of fat.
 Discuss about cholesterol.
Protein
Protein is one of the most important nutrients in our
food because it is the chief constituent of the body
cells, of body tissues and of body fluids.
Functions of Protein:
►Growth factor.
► Body tissue repair.
►Formation of globins.
►Formation of enzymes and hormones.
►Equilibrium of the osmotic pressure.
►Formation of immune system.
Essential and Nonessential Amino acids
Amino acids are the chemical building blocks from
which new proteins are made. The value of proteins
is dependent upon combinations of amino acids that
build the protein.
Essential Amino acids: There are nine amino acids
that are essential to human health and nutrition. A
food that has all the essential amino acids an
individual needs is called a complete protein.
Complete proteins support growth and normal
maintenance of body tissues. . Milk, eggs, cheese,
fish and meat have all the amino acids.
Nonessential Aminoacids: Some plant foods contain
protein, but do not have all the essential amino acids the
human body needs. They are called incomplete proteins
or non essential amino acids. Incomplete proteins lack
one or more essential amino acids but will neither
support growth nor provide normal maintenance of body
tissues. Rice, wheat and corn, for example, are missing
some of the nine essential amino acids.
Recommended amount of Proteins
The daily requirements of the body for proteins are
approximately 1 gram/kilograms of normal
bodyweight. During pregnancy the requirement
increases to 1.3 – 1.5 gm/ kg and 2 gm / kg during
lactation.
Important Sources of Protein

Plant Sources :
Bread, cereal, rice and pasta group, dry beans & nuts,
fruits (small amount of protein in fruits).

Animal Sources:
Milk, yogurt and cheese group, meat, poultry and fish.
Protein Deficiency
1 Growth slows down or stops for young child.
2 Failure to digest and absorb the food leading to diarrhea
and loss of water and electrolytes.
3 Failure of the liver to maintain normal structure and
function leading to edema.
4 Failure to maintain the structure of skeletal muscles and
the production of red blood cells leading to muscle
wasting and anemia.
Secondary or conditioned protein deficiency may
arise as a result of pathological processes. The
following are examples:
1 Loss of protein in the urine as a result of disease of the
kidneys.
2 Loss of protein from the body by other source, such as
hemorrhage and serous exudates from wounds.
3 Failure to absorb protein in various disorders of the intestine.
4 Failure by a damaged liver to synthesize protein.
5 Damage to tissues (trauma), injuries such as burns, fractured
bones or surgical operations.
NUTRITIONAL ELEMENT
FAT
FAT
Fat (Lipids) provide a concentrated source of energy.
Lipid which covers all the chemical substances included
in the housewife's fat. Triglycerides, phospholipids,
steroids….etc. Lipids have been defined as substance
which are insoluble in water but soluble in organic
solvents such as ether, chloroform and benzene.
FUNCTION OF FAT:
1 The main source of energy in the body.
2 Transfer of vitamins.
3 Protective layer under the skin.
4 Keeping body temperature.
5 Protective layer around all organs in the body.
6 Formation of cholesterol (essential substance in brain
structure).
Lipid Classification:
►1 Triglycerides (Neutral fats)
►2 Phospholipids: Contain phosphate
►3 Sphingolipids: Contain sphingosine.
►4 Glycolipids: Contain carbohydrate
►5 Steroids: Are high molecular weight compounds
include cholesterol.
►6 Waxes: Are esters of fatty acids with alcohol.
Problems Associated with excess Fat
►1
Fat is often associated with cholesterol and health
problems.
►2 Excessive amounts of fat taken with meals interfere
with digestion and, of course, if persisted in, will result
in obesity. Being overweight is the cause of many
troubles in the body, besides much inconvenience.
Types of Fat
►FATTY ACIDS are the basic chemical units or organic
acids which make up fat. All fat is one of three types of
fatty acid:
►SATURATED - found in animal sources such as milk,
cream, cheese, butter, meat, and poultry. Also in coconut
and palm oil. Because it can be made from saturated
fatty acids, cholesterol levels in the blood are related to
the amount of saturated fat eaten. Appear to raise LDL or
bad cholesterol.
►POLYUNSATURATED - are better than saturated fats.
They are found in vegetable oils and fish. Seem to help
lower cholesterol levels.
►MONOUNSATURATED - the best type of fat. It is
found in olives, avocados, nuts, and olive, canola and
peanut oils. Most margarines and hydrogenated
vegetable oils are highly monounsaturated. These seem
to lower LDL and raise HDL levels.
All three types of fats have the same number of calories.
Recommended amount of Fat
►For 2,000 calorie recommends 6 teaspoons of oil per day.
10% of your total calories should come from fat, or about
22 grams of fat/day.
Important Sources of Fat
1) Animal fats
They are obtained from:
Animal foods: Full cream milk, cheese, egg yolk and fatty meats of
animals, poultry and fish
Prepared Fat : Cream, butter, and cooking fat ghee
2) Vegetable oils
a) Plant foods: Sesame, olives, peanuts and nuts
b) b) Prepared Oils: Prepared from variety of plant
seeds as olives and corn.
Fat Absorption:
•
In the process of digestion and absorption, the fatty
acids are mixed, so that the triglycerides of the food, loss
their identity and new triglycerides partly characteristic
of the animal species are formed.
• After re synthesis, the triglycerides enter the lacteals of
the small intestine as small particles form 0.1-0.6um in
diameter known as chylomicrons.
• These pass into the lacteals and the mesenteric lymph
vessels, enter the thoracic duct and then the systemic
circulation via the right sub clavian vein.
• The major part of the fat absorbed enters the circulation
via the thoracic duct except for most short and medium
chain fatty acids which pass to the liver via the portal
CHOLESTEROL
CHOLESTEROL is a fat-like substance made by the body
which is manufactured by the liver from the fatty foods
we eat and plays a vital part in allowing the body to
function normally.
It has some useful functions:
►Found in every body cell.
►Part of skin tissue.
►Transports essential fatty acids.
►Needed to produce hormones.
A diet of foods high in cholesterol and saturated fat will
increase the "blood cholesterol level" of many people. As
a result plaque can build up in the arteries
(atherosclerosis) which increases the risk of heart attack
and stroke.
Your body makes the cholesterol it needs, eliminating the
need to include it in your diet. It is present in all animal
tissues, milk products and egg yolks, chicken legs, fins or
wings anything that can walk, swim or fly.
Cholesterol is not found in foods of plant origin such as
fruits, vegetables, grains, dry beans and peas. Cholesterol
is found in the membrane between the cells not in the
cells or fleshy part of the meat.
Types of Cholesterol:
Sometimes you hear about “good” and “bad” cholesterol.
1. LDL or low-density lipoprotein takes cholesterol from the
liver to wherever it is needed. Excess amounts of LDL can
build up on artery walls and increase risk for heart disease.
LDL is the “bad” cholesterol.
2. HDL or high-density lipoprotein, the “good” cholesterol,
picks up excess cholesterol and takes it back to the liver for
excretion. (Food for Life)
Amount of Cholesterol:
Amount of cholesterol can be ranged from 3.6 – 7.8 mmol
/ liter. A level above 6mmol/liter is considered as high
and a risk factor for arterial disease. Recommended
target of cholesterol level is less than 5 mmol/ liter.
VITAMINS, MINERALS
&
WATER BALANCE
General objective
After completion of this Unit, the students should be able
to recognize the importance of vitamins in the body.
Specific Objectives:
After completion of the class students should be able to:
 Understand the importance of vitamins.
 Know the causes of vitamins deficiency in the body.
 Identify the fat-soluble vitamins from the water- soluble




vitamins.
Recognize the general functions of minerals.
Identify major minerals from trace minerals.
Discuss the functions of water in the body and its
requirements.
Recognize the acid base balance.
VITAMINS
Vitamins are chemicals of an organic nature that occur
in minute quantities in foods and are necessary for life
and growth and found in nearly all the foods. They do
not supply energy as carbohydrates, fats and proteins
do, but they are essential because they regulate the
body chemistry and body functions.
Vitamins cannot be produced by our bodies. They must
be ingested (eaten in our food). Vitamins assist the body
in using food by bringing about biochemical reactions so
life can be maintained.
Avitaminosis- Means without vitamins, it denotes a
deficiency or lack of sufficient vitamins to carry out
normal body function.
Hypervitaminosis- Is an excessive accumulation of a
vitamin in the body leading to toxic symptoms.
Importance of Vitamins
Metabolic control agent – “Co enzyme partner”: In many
cell reactions a particular vitamin is necessary as a
coenzyme partner with the regular cell enzyme to allow
the reaction to proceed.
 Tissue Structure: Some vitamins act as tissue or bone
building component. For example vitamin C.
 Antioxidants: Vitamins act as antioxidant to protect cell
structure and to prevent free radial damage.
 Prevention of deficiency diseases: If the vitamin is not
taken adequately deficiency diseases occur according to
the functions of that vitamin.
Causes of Vitamin Deficiency in the Body
a) Life cycle needs: Vitamins needs change with age and
situation through out the life cycle.
1. Pregnancy and Lactation: Women may find it difficult
to meet the increase need of pregnancy by diet alone
because of nutrient tolerance, food preferences or other
factors that can lead to a marginal diet.
2. Infancy: Rapid growth in infant demand more vitamins.
3. Children and adolescent: This age utilizes more total
nutrient including all vitamins than during adulthood.
During adulthood growth has slowed or stopped.
4. Aging: The aging process may increase the need for
some nutrients because of decreased food intake and
impaired nutrient absorption, storage and usage.
b) Life Style : Personal life style choices or habits may
influence the individual needs for nutrient
supplementation.



Oral Contraceptive Use: Woman using oral
contraceptive agents find that this practice lowers
serum levels of several B vitamins including pyridoxine
and niacin as well as vitamin C.
Restricted Diet: Person who is always dieting may find
it difficult to meet many of the nutrient standards,
particularly if their meals provide less than 1200 kcal/
day.
Exercise programs: Woman on extended exercise
program may increase their requirement of riboflavin.



Smoking: This unhealthy habit, especially among
women during their childbearing years, affects health
and can reduce vitamin c levels.
Alcohol: Chronic or abusive use of alcohol can interfere
with absorption of B complex vitamins, especially
thiamin.
Caffeine: In large quantities caffeine flushes water
soluble vitamins out of the body faster than usual.
 Classification of Vitamins
 Fat Soluble vitamins: Fat-soluble vitamins are absorbed
from the intestine and transported in to the circulation.
Once absorbed in to the circulation these vitamins are
carried to the liver where they are stored.
 2 Water Soluble Vitamins: Water-soluble vitamins are
dissolved in water and transported through the body.
They are stored in the body for only a period of time and
are then excreted by the kidneys.
FAT-SOLUBLE VITAMINS
Vitamin A
Vitamin D
Vitamin E
Vitamin K
WATER-SOLUBLE VITAMINS
Vitamin C (ascorbic acid)
Vitamin B Complex
B1 (thiamin)
B2 (riboflavin)
Niacin
B6 (pyridoxine)
B12 (cobalamin)
Folacin (Folate or Folic Acid)
Fat Soluble Vitamins
Vitamins
1
Vitamin A
(BetaCarotene or
Retinol
Functions
It combines with
a protein to
form "the
protein
pigment" retinal
or visual purple
which is
responsible for
light adaptation.
2 It maintains
the integrity of
the epithelial
structure.
3 It participate
in the formation
of
mucopolysacchri
des in the
matrix of bone
and teeth.
Sources
Signs Of
Deficiency
Beef, liver,
carrots, spinach
and tomatoes.
1 Night
blindness,
Xerophthalmia
(dryness of
conjuctiva), and
Keratomalacia
(softening of the
cornea)
2 The columnar
epithelial cells
change into
stratified form
which invites
infection, so we
get recurrent
attacks of
bronchitis,
gastroenteritis..et
c.
3 Faulty
epiphyseal bone
formation.
Dietary
Treatment
4000-5000
Units/Day
Vitamins
2
Vitamin D
Functions
1. Mobilize
the calcium
from fully
calcified
bone
making it
available for
the
formation of
new bone.
2. Maintain
calcium
level.
3.Prevents
rickets
Sources
Signs Of
Deficiency
Fish , Milk,
liver oils,
exposure to
ultraviolet
rays.
1 1 Rickets in
children
2.Osteo
malacia
3 Infantile
tetany
4 Dental
decay
Dietary
Treatment
400
I.U./day
Vitamins
3
Vitamin E
Functions
Helps breakdown
polyunsaturated
fats
Antioxidant,
protecting blood cell
membranes from
over exposure to
oxygen
(no proof of a role
in aging, sexual
performance, or
prevention of
cancer and/or heart
disease)
Sources
Pure
vegetable
oils, wheat,
whole meal
bread and
cereals, egg
yolk, nuts ,
sunflower
seeds, whole
grain
vegetables
and seed oils
Signs Of
Deficiency
Dietary
Treatment
Muscle
wasting, red
For Men –
10 mg
Women –
8 mg
blood cell
damage,
hemolytic
anemia,
hemorrhaging,
reproductive
failure,
neurological
abnormalities
Vitamins
4 Vitamin K
Functions
Essential for
clotting of
blood
Found in foods
and
manufactur
ed by
Vitamin K
producing
bacteria in
the small
intestines
Blood calcium
regulation
Protein
synthesis
Sources
Signs Of
Deficiency
Dietary
Treatment
Dark green
vegetables,
cabbage
type
vegetables
Bleeding due
For Men –8
mg
Women – 6
mg
to delay
clotting
times caused
by lack of
clotting
factors.
Patients may
show signs of
bruising
easily and
have nose
bleeds.
Vitamins
1
Vitamin C
(ascorbic acid)
Functions
Water Soluble Sources
Vitamins
1 Helps form
collagen or
body cement
2 Helps in
growth and
repair
of body tissue
and blood
vessels
3. Prevents
scurvy
4. Essential for
maintenanc
e of bones,
teeth and
gums
5. Necessary for
ensuring
normal
immune
response to
infection,
wound
healing and
iron
absorption
Citrus fruits,
berries,
mangos,
papayas,
melons,
tomatoes ,
green leafy
vegetables
Signs Of
Deficiency
Dietary
Treatment
Anemia,
scurvy,
depression,
infections,
bleeding gums,
muscle
degeneration,
poor wound
healing,
capillary
hemorrhaging
For Men &
Women – 40
mg
Water Soluble Vitamins
Vitamins
1
Vitamin C
(ascorbic acid)
Functions
1 Helps form
collagen or
body cement
2 Helps in
growth and
repair
of body tissue
and blood
vessels
Prevents scurvy
Essential for
maintenanc
e of bones,
teeth and
gums
Necessary for
ensuring
normal
immune
response to
infection,
wound
healing and
iron
absorption
Sources
Signs Of
Deficiency
Dietary
Treatment
Citrus fruits,
berries,
mangos,
papayas,
melons,
tomatoes ,
green leafy
vegetables
Anemia,
scurvy,
depression,
infections,
bleeding gums,
muscle
degeneration,
poor wound
healing,
capillary
hemorrhaging
For Men &
Women – 40
mg
Vitamin B Complex
Vitamins
Functions
Sources
Signs Of
Deficiency
Dietary
Treatment
1
B1 - Thiamine
Energy
metabolism
, nerve
function, &
muscle
control
Yeast, egg,
yolk, liver,
wheat germ,
nuts, red
meat, fish,
whole grain
breads and
cereals
Fatigue,
irritability, loss
of appetite,
severe
deficiency can
lead to Beriberi
2
B2 - Riboflavin
Involved in use of
fat, protein
and
carbohydra
tes
Liver red
meat, dairy
product, eggs
,dark green
vegetable, ,
yogurt, bread
Pernicious
anemia,
paralysis,
Men-1.3 mg
Women –
1.1 mg
3
Niacin
Energy
metabolism
, maintain
healthy
nervous
system and
skin
Yeast, meat,
eggs, liver,
cereal, seeds,
milk, green
leafy
vegetables,
fish, nuts
Pellagra,
dermatitis on
body parts
exposed to sun,
diarrhea, loss of
appetite,
weakness,
fatigue
Men-19 mg
Women –
15 mg
Men - 1mg
For Women
– .8mg
Vitamin B Complex
Vitamins
Functions
Sources
Signs Of
Deficiency
Dietary
Treatment
1
B6
(Pyridoxine)
Normal immune
and
nervous
system
Meat, fish
green leafy
vegetable,
bananas
Central nerve
system disorder,
seizure, anemia,
muscle
weakness
Men-1.4 mg
Women –
1.2 mg
2
B12
Producing
antibodies,
helps
folacin
function,
maintenance of
nerve
tissue
Meat, fish,
milk eggs,
yeast, cheese
Paralysis,
smooth tongue,
fatigue,
dementia,
depression
Men &
Women -.002 mg
Synthesize DNA
Cell division
Liver, meat,
eggs, milk,
fruits, cereals
Glossitis,
cheilosis,
gastrointestinal
disturbances like
diarrhea,
abdominal
distention
Men &
Women – .2
mg
(Cobalamin)
3
Folacin
( folic acid)
MINERALS
Minerals are found in nearly all the foods but they do
not supply energy as carbohydrates, fats and proteins
do, but they are essential because they regulate the
body chemistry and body functions.
Minerals cannot be produced by our bodies. They must
be ingested (eaten in our food).
Minerals are sometimes chemical constituents of
vitamins. Minerals are also found in enzymes,
hormones, bones and muscles.
Minerals can become part of the body’s structure. There
are about sixty different minerals that make up about
four percent of the body. Science is still learning about
many of the functions of minerals.
Minerals are also divided into two groups:
1. Macro minerals (Major Minerals) are found in
relatively large amounts. Required Intake is ≥ 100
mg/day.
2. Trace minerals are found in very small amounts in
the body. Required Intake is ≤ 100 mg/day.
Macronutrients
Calcium
The body of an adult normally contains about 1200g of
calcium. Atleast 90% of this amount is present in
skeleton and teeth.
Sources: Milk, dairy products
Excretion:
- In the feces where most of the calcium found in the stool.
-In the urine
-In the sweat.
Recommended Intake:
Age
Allowance (mg daily)
0-12 month
1-9 month
10-15 month
16-19 month
500-600 mg/day
400-500 mg/day
600-700 mg/day
500-600 mg/day
I. Hypocalcaemia (Calcium deficiency):
In infants: Rickets, soft bone, enlarged joints,
deformed skull, spinal curvature, bowed legs.
In adults: Osteomalacia, weak bone.
II. Hypercalcaemia:
A) In infants: Loss of appetite, vomiting, wasting,
constipation, flabby muscles, and a characteristic
facial appearance.
B)In Adults: There is no danger of excessive calcium
intake, since the homeostatic mechanism of the body
ensure that the amount of calcium retained from the
food does not exceed the amount needed to replace
the wear and tear of bones and soft tissues.
(2) Phosphorus:
Phosphorus is present in all natural foods; Most of the
phosphate in the body is present in bone and teeth.
(3) Magnesium:
All human contains small amount of magnesium. The whole
adult body contains about 25 gm, the greater part of this
amount is present in the bone, and about one-fifth of the total
magnesium in the body is present in the soft tissues, where it is
apparently mainly bound to protein.
Magnesium Deficiency: Occurs when excessive losses of
magnesium in the faeces or urine occur in many diseases and
the resulting magnesium deficiency leads to apathy and
muscle weakness and sometimes to tetany and convulsions.
(4) Sulphur:
All living matter contain proteins and all proteins
contain sulphur, which is essential for life.
The greater part of the Sulphur in the human body is
present in the two Sulphur containing amino acids;
methionine and cystine.
Two known vitamins, thiamine and biotine contain
sulphur.
Most of the sulphur in the diet is provided by the
sulphur containing amino acids.
(5) Iron:
The amount of iron in the body is about 4 grams,
distributed in the body as follows: 2.5 g in
haemoglobin, 0.3 g in tissue iron, and 1.0 g in
iron stores. Tissue iron is present in myoglobin and the
cytochrome. Iron is thus an essential component of
three different processes involved in the transfer of
oxygen, and hence is of great importance in human
nutrition deficient supply of iron is a very common
cause of anemia.
(6) Zinc:
The total body content of zinc in an adult is over 2.0 g.
It is necessary part of more than 20 enzymes. The tissues
that contain the highest concentration of zinc are the
choroids of the eye and the prostate.
Deficiency state: A clinical syndrome characterized by
small stature, hypogonadism and mild anemia.
II.TRACE ELEMENTS
(1) Iodine:
The adult body 20-50 mg of iodine, about 8 mg in the thyroid
gland.
Source: Sea foods.
Deficiency: Goiter (enlarged thyroid gland).
(2) Fluorine:
Present in human tissue, notably the bones, teeth, thyroid
gland and skin.
Sources: Drinking water, the fluoride in food stuff is of little
importance, sea fish may contain relatively large amounts,
another significant source is tea.
Deficiency: leads to dental caries, osteoporosis.
Excessive intake: leads to fluorosis, which is mottling of the
teeth by brown pigmentation. The Fluoride deposits in dental
enamel.
(3) Copper:
Normal adult diet provides 1-3 mg/day. Green vegetables and liver
are good sources whereas milk, meat, bread is a poor sources.
Function: is a component of many enzyme systems.
Deficiency: may lead to anemia or chronic diarrhea.
(4) Cobalt:
Is a constituent of vitamin B12.
(5) Chromium.
(6) Manganese.
(7) Molybdenum.
(8) Nickel.
(9) Silicon.
(10) Aluminum.
Mineral Elements
Gm
I- Macronutrients:
Calcium
Phosphorus
Sulphur
Iron
Zinc
II- Micronutrients:
Iodine
Fluorine
Manganese
Copper
Selenium
Cobalt
Principal location in the body
1050-1540
560-840
175
2.8
99% in bone and teeth
80-90% in bone and teeth.
Associated with proteins
Hemoglobin, liver
0.02
0.21
0.11
Thyroid gland
Bone and teeth
Vitamin B12 molecule
Summary of Mineral Elements
(A) Macronutrients
Element
Function
Utilization
Daily Allowance
Calcium
99% in bones, teeth,
nervous
stimulation, muscle
contraction, blood
clotting, activates
enzymes.
10-40% absorbed aided by
vitamin D and lactose,
parathyroid hormone,
regulates blood level.
Phosphorus
80-90% in bone, teeth,
acid – balance,
transport of fats,
enzymes for energy
metabolism.
Vitamin D favors absorption
and use.
RDA:
800mg
Milk, cheese, meat,
fish, cereal, nuts
Magnesium
60% in bone, teeth,
transmit nerve
impulse, muscle
contraction,
enzyme for energy
metabolism.
Salts relatively insoluble acid
favors.
RDA:
300-350
RDA:
800mg
Milk, cheese, ice
cream, mustard.
Element
Function
Utilization
Daily Allowance
RDA:
Men: 10 mg
Female: 18 mg
Iron
Mostly in
hemoglobin,
muscle
myoglobin,
oxidizing
enzymes.
5-20% absorption, acid and
vitamin C aid
absorption, daily losses
in urine, feces,
menstrual losses,
anemia is common.
Zinc
Enzymes for
transfer or
carbon dioxide
taste.
Little like hood of
deficiency or excess
Iodine
Form thyroxin for
energy
metabolism.
Chiefly in thyroid gland,
deficiency leads to
endemic goiter.
Prevent tooth decay
Dental enamel
Fluorine
RDA;
15mg, plant and
animal
protein.
RDA:
100-140mg, iodize
salt, shellfish, salt water
fish.
Fluoridated
water.
FLUID AND ELECTROLYTE
BALANCE
FLUID AND ELECTROLYTE BALANCE
About 50-60% of the total body weight is made up of
water; the proportion varies somewhat, with fat
persons having less body water than lean persons;
infants and young children have more body water than
older persons, about 3/4 of the water in the body is
within the cells, this is referred to as intracellular fluid.
The remaining water is in the blood and lymph
circular and in the fluids around the cells and tissues
this is called extra cellular fluid.
The body of a 65 kg man contains approximately 40
litres of water, of the about 25 litres are within the cells
and about 15 litres in the extra-cellular fluids.
Functions:
1. Water is the solvent for materials within the body,
the food we eat are digested by enzymes in an
abundance of digestive juices:
2. The nutrients are carried in solution across the
intestinal wall, the blood transports nutrients to all
body tissues:
3. Materials dissolved in water are transported across
the cell membrane, chemical reactions take place
in the presence of water and body waste are carried
by the blood for elimination by the kidneys, lungs,
skin and bowel.
4. Water is also a lubricant, it avoid friction between
moving body parts and regulates the body
temperature, thus giving a cooling effect.
Water balance
The water intakes comprise the fluid drunk and the water
in the food eaten. The water formed by the oxidation of
carbohydrate, protein, and fat is also available. The
output consists of the urine, the water in the faeces and
the water evaporated from the skin and lungs.
Water retention and depletion:
Edema:
This is the condition when excess fluid in the body causes
the subcutaneous tissues to swell and pit when pressure is
applied with the finger.
It is important to remember, however ,that this simple
clinical test is not very sensitive: edema is not usually
apparent until the limb volume is increased by 10% or more.
Over hydration sometimes results in edema of the lungs
which causes difficulty in breathing.
Dehydration:
This can be suspected from the sunken features,
particularly the eyes which recede into the orbits. The skin
and tongue are dry, the skin becomes loose and lacks
elasticity. On pinching it stands up, away from the
subcutaneous tissue. The patient is usually, but not always,
thirsty.
Sodium and potassium in the body
The body of a 65 kg man contains about 4000 mmol of
Na, equivalent to 256 g NaCl, of this the major part,
just over half, is in the extra-cellular fluid, about 1500
mmol is in bone and less than 500 mmol in the cells.
By contrast, the potassium content of the extracellular fluids is only about 80 mmol, whereas the
tissues contain about 3500mmol. Four fifths of this
amount is in the skeletal muscles.
Intake of sodium:
Most normal people ingest 5-18 g NaCl/day,
corresponding to 70-300 mmol Na. The food as served
seldom contains more than 200 mmol NaCl/day: the
remainder is taken as table salt.
In general, natural foods contain relatively little
sodium, but large amounts may be added in cooking,
either as NaCl or as sodium bicarbonate in baking
powder also in most forms of processing and
preserving, salt is added.
Intake of potassium:
The potassium contains of food stuff is very variable: natural
diets provide from 50-150 mmol k/day. The usual figure is about
65 mmol/day, equivalent to 5 g of potassium chloride.
Potassium deficiency or excess rarely arise primarily as a result
of dietary deficiency or excess common foods contain moderate
amounts. Cereals(including rice and wheat),cheese, eggs, fats
and almost all fresh fruits contain less than 8 mmol/100g have
been used in constructing low potassium diets.
Sodium depletion:
Is characteristically associated with dehydration, as for
instance in heat exhaustion. The essential chemical pathology
is a reduction in the extra-cellular fluid as a result of the low
blood volume, the veins are collapsed, blood pressure is low.
Sodium excess:
An excess of sodium in the body accumulates in the extracellular fluid. The increased concentration of sodium is
partially by increase in these fluids. Sodium excess result in
edema, with high blood pressure.
Potassium deficiency:
Features of potassium deficiency are muscular weakness and
mental confusion. They are probably caused by a periodic over
secretion of aldosterone by the adrenal cortex. The smooth
muscle of the small intestine may become paralized(paralytic
ileus).
Potassium excess:
The toxic effects of K fall on skeletal and cardiac muscle.
Muscular weakness and mental apathy are generally marked.
Causes of potassium excess include rental failure, adrenal
insufficiency or shock after injury.