11. Nutrition, Vitamins and Trace Elements 1a.ppt

Nutrition, Vitamins and
Trace Elements
By
Bose E. Orimadegun, Ph.D.
Department of Chemical Pathology
College of Medicine, University of Ibadan

Bose E. Orimadegun, PhD
Dept. Chemical Pathology, College of Medicine, University of Ibadan
Learning Objectives
At the end of the lecture, students must be able to:
• Define the following terms: nutrition, nutrients, vitamins and
trace elements.
• Give examples, functions and sources of nutrients.
• Differentiate between macro- and micro-nutrients.
• Describe vitamins and their classification.
• State their importance in metabolism.
• Describe the diseases associated with their deficiency and
toxicity.
• Explain the prevention or treatment of some of the disorders
associated with these nutrients.
2

Definition of Terms
Nutrition
• The science of food and its relationship to health.
• The process by which the body takes in and uses food.
• It is concerned primarily with the part played by nutrients in
body growth, development and maintenance.
Nutrient
• A chemical or chemical compound that aids in the support of
life, and is essential for the normal function, growth and
reproduction of the animal.
3

Definition of Terms (Contd.)
Vitamins (from Latin word for Life “Vita”)
• They are organic substances that act as coenzymes,
chemicals that assist the enzymes in the reactions of
the body.
• They do not provide energy or calories.
Trace Elements/Minerals
• Require in small amounts.
• Found in plants and animals.
• Bioavailability often influenced by other dietary factors
(especially other minerals)
4

5
Nutrients
• Nutrients are broadly divided into:
• Macronutrients:
– Proteins
– Fats
– Carbohydrates
– Water
• Micronutrients:
– Vitamins
– Minerals

6

Macronutrients
• Are a class of chemical compounds that
constitute the bulk of the diet and supply
energy and many essential nutrients. e.g.
– carbohydrates,
– proteins
– fats, macro-minerals, and water.
7

Carbohydrates
• Carbohydrates are the starches and sugars present
in food.
Classification:-
Complex Carbohydrates : They are starches.
Examples include whole grains, seeds.
• Fiber is an indigestible complex carbohydrate that
helps move waste through the digestive system.
Simple carbohydrates: are sugars. Examples
include Glucose, fructose, lactose.
– Minimum carbohydrates = 100 g/day
8

Carbohydrates
• Carbohydrates are the preferred source of
energy.
• The body converts all carbohydrates to
glucose.
• Glucose not used is stored as glycogen.
• Excess carbohydrates are stored as fat in
the body.
9

Proteins
• Proteins are nutrients that help build and maintain body
cells and tissues.
Classification:
a) Complete Proteins:- animal proteins that contain all nine
essential amino acids.
Sources include:
• Fish, meat, poultry, eggs, milk, cheese, yogurt, and many
soybean products.
b) Incomplete proteins:- plant proteins. They lack one or
more essential amino acids.
Sources Include:
• Beans, peas, nuts, and whole grains.
10

Proteins
• Proteins are useful in the body to
– make new cells.
– make and repair tissues.
– make enzymes, hormones, and
antibodies.
–Provide energy.
Amino acids are used to build structural
proteins and enzymes in the body
11

Fats
• Fats are a type of lipids (mostly triglycerides), a fatty
substance that do not dissolve in water.
• The building blocks of fats are called fatty acids
Classification of Fatty Acids:
1) Saturated:
– Animal fats and tropical oils
• High intake is linked to increased cholesterol production
• Excess cholesterol can lead to an increased risk of heart
disease.
2) Unsaturated:
– Vegetable fats
– Associated with a reduced risk of heart disease
12

Fats
• Fats transport fat soluble vitamins
• Linoleic acid is an essential fatty acid that
is needed for growth and healthy skin
Other uses include:
• Phospholipids for membranes and myelin
• Cholesterol for membranes, vitamin D,
steroid hormones, and bile salts
13

• Water helps to maintain many bodily functions.
– Lubricates the joints and mucous membranes.
– Enables food to be swallowed and digested.
– Absorb other nutrients, and eliminate wastes.
– Perspiration helps maintain normal body
temperature.
– Water makes up around 65% of the body.
– It is important to drink at least 8 cups of water
a day to maintain health.
14

Micronutrients
Micro nutrients
• are nutrients required by humans and other
organisms throughout life in small quantities
to coordinate a range of physiological
functions
16

Water-soluble vitamins
– dissolve in water and pass
easily into the blood
during digestion.
– The body does not store
these so they need to be
replenished regularly.
– Includes vitamins C, B1
,B2, Niacin, B6, Folic acid,
and B12.
Fat-soluble vitamins
– are absorbed, stored,
and transported in fat.
– The body can store
these vitamins in fatty
tissue, liver, and
kidneys.
– Excess build up can be
toxic.
– These include vitamins
A, D, E, and K.
Vitamins help to regulate many vital body processes that include:
1. Digestion 2. Absorption 3. Metabolism
4. Circulation
Vitamins are classified into two groups:
17

18

Vitamin A
• Source: fish, liver, eggs, butter,
yellow green vegetables and fruits
• Use: Needed for healthy skin, eyes,
bones, teeth.
• Deficiency: causes night blindness,
skin disorders, kidney stones
19

Vitamin D
• Source: liver, fish, eggs,
milk, sunlight.
• Use: Needed for growth,
healthy bones, metabolism of
calcium (Ca) and phosphorus
(P).
• Deficiency: causes rickets,
poor teeth and bones.
20

Rickets
•Weakness and deformity of the bones that occurs
from vitamin D deficiency or dietary deficiency of Ca
and P in a growing person 21

Vitamin E
• Source: whole grains, leafy vegetables,
milk, butter and vegetable oils
• Use: antioxidants
– Needed for healthy cell membranes, red
blood cells
• Deficiency: causes red cell rupture,
muscle disorders
22

Vitamin K
• Source: Leafy vegetables, soybeans,
made by intestinal bacteria
• Use: Needed for normal blood clotting
• Deficiency: causes slow clotting,
hemorrhaging.
23

Water Soluble Vitamins
–B1 (Thiamine)
–B2 (Riboflavin)
–B3 (Niacin)
–B5 (Pantothenic Acid)
–B6 (Pyridoxine)
–B7 (Biotin)
–B12 (Cobalamin)
–Folic Acid
–C (Ascorbic acid)
24

Vitamin B1 (Thiamine)
• Source: organ meats,
whole grains,
vegetables
• Use: Needed for
proper functioning of
heart, nervous system,
digestion
• Deficiency: causes
beriberi, cardiovascular
disorders. 25

Vitamin B2 (Riboflavin)
• Source: liver, poultry, milk, eggs,
cheese, fish, green vegetables, whole
grain
• Use: metabolism of protein,
carbohydrates, and fats as well as
healthy skin
• Deficiency: causes dim vision,
premature aging, sore mouth
26

Niacin
• Source: red meats,
organ meats, fish,
green vegetables.
• Use: to make NAD for
metabolism, digestion,
nerves, skin.
pellagra, sore mouth,
diarrhea, depression.
27

Vitamin B6 (Pyridoxine)
• Source: meats, liver, whole grains,
vegetables
• Use: Needed for sodium and phosphorus
balance
• Deficiency: causes anaemia, nausea,
loss of appetite, nervousness
28

Vitamin B12
• Source: Liver, meats, eggs, cheese, dairy products.
• Use: for red cell production, healthy nervous system,
new cell synthesis, normal brain and nervous system
functioning or maintenance, DNA regulation and
synthesis, myelin sheath (essential covering around
nerves), metabolism of every cell in the body and
synthesis of fatty acids and energy production
• Deficiency: causes pernicious anaemia (due to lack of
intrinsic factor which is produced in the stomach and is required for
absorption in gut), Irreversible nerve and brain damage,
elevated homocysteine levels which may increase
the risk of heart disease
29

Folic Acid
Source: green vegetables, liver, whole grains, legumes
Use: as a coenzyme along with B12 and vitamin C required for:
– Amino acid and protein synthesis
– DNA and heme synthesis, the iron containing substance
in haemoglobin
• Formation of the coenzyme referred to as tetrahydrofolate
(THF),
• Synthesis of new cell and present in rapidly growing cells
• Very important in early pregnancy for
– DNA synthesis,
– proper formation of the brain, spinal cord, and nerve cells
in the embryo and closure of the neural tube in the fetus
• Essential for synthesis of serine, methionine, and ATP

Folate Deficiency and Neural Tube
Defects
Deficiency causes inflamed tongue, diarrhea, B12
deficiency, megaloblastic anaemia, low birth weight,
neural tube defects, frequent infections and elevated
homocysteine levels (risk for heart disease). 31

Macrocytic Anaemia and Folate
Deficiency
32

Vitamin C
• Source: citrus and other
fruits, leafy vegetables,
tomatoes, potatoes.
• Use: for healthy blood
vessels, resistance to
infection, healing as well
as antioxidant that protects
the tissues and cells
against oxidative damage.
scurvy, bruising, bleeding
gums.
33

34

Minerals in the Body
• Minerals are elements needed
– by the body in small amounts for health and
maintenance.
– in the diet in amounts >100 mg per day or
are present in the body in amounts > 0.01%
of body weight.
• Trace minerals are required in the diet in
amounts < 100 mg per day or are present
in the body in amounts < 0.01% of body
weight.
35

Nutritionally Important Minerals
Macro Trace
Element g/kg Element mg/kg
Ca
P
K
Na
Cl
S
Mg
15
10
2
1.6
1.1
1.5
0.4
Fe
Zn
Cu
Mo
Se
I
Mn
Co
20-50
10-50
1-5
1-4
1-2
0.3-0.6
0.2-0.5
0.02-0.1
36

Functions of Minerals
• Some participate with enzymes in
metabolic processes (cofactors e.g. Mg,
Mn, Cu, Zn, K)
• Some have structural functions (Ca, P in
bone; S in keratin)
• Acid-base and water balance (Na, K, Cl)
• Nerve and muscle function (Ca, Na, K)
• Unique functions (e.g., Fe, Vitamin B12
(Co), thyroxine)
37

Minerals in the Diet
38

Iron
• Dietary requirements:
– Adult man: 10 mg/day
– Menstruating woman:
18 mg/day
– Pregnant and lactating
woman: 40 mg/day
• Sources:
– Rich source: organ meats
(liver, heart, kidney).
– Good source: leafy
vegetables, pulses, cereals,
fish, apple, dried fruits,
molasses.
– Poor sources: milk, wheat,
polished rice.
Deficiency
Result from
1. Insufficient intake and storage
2. Reduction in the production of
RBCs and oxygen capacity
Causes
1. Common form of anaemia (30%
of world population)
2. Low levels of hemoglobin and
hematocrit
• People at risk: Infants, growing
children, pregnant women,
toddlers, chronic blood loss,
vegans, runners, and women of
childbearing years
• Symptoms include paleness,
brittle nails, fatigue, difficulty
breathing, poor growth
39

Disease states
1. Iron Deficiency Anaemia:
• The most common dietary deficiency worldwide is
iron.
• It affects half a billion persons worldwide with
women and children at more risk.
a) A growing child is increasing the RBC mass
and needs additional Fe.
b) Women who are menstruating require double
the amount of Fe that men do, but normally
the efficiency of Fe absorption from the
gastrointestinal tract can increase to meet
this demand.
c) A developing fetus draws Fe from the mother,
totaling 200-300 mg at term, so extra iron is
40

2. Hemosiderosis:
• This is less common disorder and due to excessive iron in
the body.
– It is commonly observed in subjects receiving repeated
blood transfusions over the years, e.g. patients of
hemolytic anaemia and haemophilia.
3. Hemochromatosis:
• This is rare disease in which iron is directly deposited in the
tissue (liver, spleen, pancreas and skin).
– Bronzed-pigmentation of skin, cirrhosis of liver.
Pancreatic fibrosis are the manifestations of this disorder.
Disease states (Contd.)
41

Iron Toxicity
• Medicinal or supplemental iron
• Most common cause of childhood
poisoning
• Symptoms
– Vomiting, diarrhea, constipation, black stools
– Death
• Excess deposited in liver, heart, muscles
42

Iodine
• Found in seafoods, iodized salt
Function
• Essential component of thyroid
hormones
– Thyroxine (T4)
– Triiodothyronine (T3)
• Important for regulation of body
temperature, basal metabolic rate,
reproduction and growth
• Regulates energy metabolism, growth,
development
• Prevents goiter
Signs of deficiency
– Severe fatigue
– Lethargy 43

Iodine Deficiency Disorders
• Cretinism • Goiter
44

Summary
• Nutrients do more than sustain life; they
support the body metabolic processes.
• Minerals are single, inorganic elements that
are classified according to their relative
amounts in the body.
• Major minerals make up 60% to 80% of all
inorganic material in the body.
• Trace elements make up less than 1% of the
body’s inorganic material.
45

•THANK YOU
46

11. Nutrition, Vitamins and Trace Elements 1a.ppt

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