This document provides an overview of nutrition including definitions, classifications and functions of major nutrients - carbohydrates, proteins, fats, vitamins and minerals. Carbohydrates are the primary source of energy and are obtained from foods like grains, fruits and vegetables. Proteins are needed for growth, tissue repair and enzyme/hormone production with sources including meat, eggs and beans. Fats provide energy storage and aid nutrient absorption from foods like oils, nuts and dairy. Vitamins and minerals are required as cofactors for metabolic processes, with common sources being various plant and animal foods.

1. OLUWADARE. T
DEPARTMENT OF COMMUNITY MEDICINE
ABUAD
*

2. *
*Nutrition is the science that
interprets the interaction of
nutrients and other substances in
food in relation to maintenance,
growth, reproduction, health and
disease of an organism.
*It includes food intake, absorption,
assimilation, biosynthesis,
catabolism and excretion.

5. *
*Nutrients are substances essential
for the health, that the body cannot
make or make in quantities too small
to support health.
*They are organic and inorganic
complexes contained in food
*They are broadly divided into
Macronutrients and Micronutrients.

7. *
*Characteristics of nutrient include
the following
*Specific biological function
*Removal and addition have effect
on health

8. *
*Food can be classified according to
*Their chemical composition
*Their predominant function
*Their origin
*Nutritive value

10. *
*CARBOHYDRATE
*They are organic compounds made
up of Carbon, Hydrogen and
Oxygen
*They are classified as
Monosaccharides, disaccharides
and polysaccharides
*Monosaccharides include glucose,
fructose and galactose.

11. *
*Disaccharides include lactose, sucrose
and maltose
*FUNCTIONS OF CHO
*Provides energy that is use for heat
and basal metabolism
*Maintain glucose level in the blood
*Indigestible parts of CHO, i.e cellulose,
provide bulk in the intestine which aid
excretion of waste products
*Essential for oxidation of fat&
synthesis of certain non-essential
amino acids

12. *
*SOURCES OF CHO
*Yam, cassava, wheat product,
sweets, sweet potatoes, fruits,
honey, maize etc.
*Energy value is 1g CHO= 17kj

13. *
*PROTEIN
*It contains carbon, hydrogen,
oxygen, nitrogen and sometimes
Sulphur or phosphorus.
*It is broken down into at least 23
different amino acids.(8 essential for
adults, 10 essential for infants)

14. *
*Animal foods contain many of the
essential amino acids but mixture of
plant protein can also supply all of
it.
*Protein have biological values that
are expressed in percentages
*Daily requirement of protein is 60-
90g for adult, 20-70g for children up
to 18yrs
*Approximately 38% of a diet should
be made up of protein

15. *
*FUNCTIONS OF PROTEIN
*Essential for growth and
development of tissues
*Required for the repair and renewal
of tissue cells
*Important for the formation of
enzymes, hormones, antibodies,
hemoglobin and antitoxins

16. *
* control the alkalinity of blood and
the osmotic pressure in blood vessels
*Production of energy
*SOURCES OF PROTEIN
*Meat, egg, fish, snails, edible insect,
guinea corn, millet, rice, groundnut
etc
*1g of protein= 17kj

19. *
*FATS AND OILS
*They are compounds of fatty acids
and glycerol
*They consist of carbon, hydrogen
and oxygen
*Fats are found in plant and animals,
but generally oils are obtained from
plants and fats from animals
*Fats take longer time to digest than
CHO

20. *
*Fats and oils should form 12% of a
person’s diet
*Energy value is 1g= 38kj
*FUNCTIONS OF FATS AND OILS
*Provide energy and heat
*Serves as packing material in the
body and help to support the kidneys
the eye and internal organs. They
also round off the bones and gives
shape to the body.

21. *
*Transportation of fat-soluble
vitamins
*Essential for the formation of nerve
sheaths
*They are needed for the secretion of
bile and sebum
*They act as lubricants
*They add flavor to food.

22. *
*VITAMINS
* They are important organic
substances
*They are catalyst and often referred
to as protective foods.
*They are essential for growth and
maintenance of the body
*There are two groups namely, fat-
soluble and water-soluble vitamins.

23. *
*VITAMIN A
*It is found in animal fats and oils
*It is absorbed through the lacteals of
the villi along with fatty acids and
glycerol
*Bile salt is essential for its
absorption
*Excess Vit. A is stored in the liver
*RDA for adults is 600mcg

24. *
*SOURCES
*Animal sources- fish, liver, oils, eggs,
creams, milk etc.
*Plant sources- green vegetables,
palm oil, pawpaw, mango, water
melon, carrots, plantain, tomatoes
etc.
*FUNCTIONS OF VIT.A
*It controls general state of epithelial
cells and reduce risk of infection

25. *
*Required for the regeneration of visual
purple in the retina of the eyes
*It supports growth especially skeletal
growth
*DEFICIENCY
*Night blindness
*Conjunctival xerosis
*Bitot’s spot
*Corneal xerosis
*keratomalacia

28. *
*VITAMIN D
*Also known as anirachitic vitamin
and chemically as calciferol
*SOURCES
*Food- fatty foods such as liver,
sardines, shark, salmon, butter, egg,
cheese, milk palm oil etc.
*Non-food source- sunlight
*RDA for adult is 2.5mcg= 100IU

29. *
*FUNCTIONS
*Promotes intestinal absorption of
calcium
*Stimulates normal mineralization
and enhances bone resorption
*Permits normal growth
*Increases tubular reabsorption of
phosphate

30. *
*VIT. D DEFICIENCY
*Crickets
*Osteomalacia

32. *
*VITAMIN E
*Known as tocopherol
*SOURCES
*Vegetable oils, cotton-seed, sun
flower seed, egg yolk, butter etc
*FUNCTIONS
*Prevents rancidity in oily foods
*It is thought to play a part in
utilization of CHO and protein and in
muscular activity

33. *
*VITAMIN K
*It occurs in two major forms
*Synthesized by intestinal bacteria
*It is stored in the liver
*RDA for adult is 0.03mg/kg
*SOURCES
*Fresh green vegetables, some fruits,
cow milk, human milk

34. *
*VITAMIN B1
*Also called thiamine
*Water soluble
*RDA is 0.5mg/1000kcal of energy
*SOURCES
*Whole grains cereals, wheat, yeast,
nuts, meat, fish, egg, fruit, milk etc.
*FUNCTIONS
*Helps metabolism of carbohydrate

35. *
*Required for normal functioning of
nervous system, GIT and pumping
action of the heart.
*It stimulates appetite
*Involved in control of fluid balance
in the body
*DEFICIENCY
*Beriberi
*Wernicke’s encephalopathy

37. *
*VITAMIN B2
*It is a yellowish substance
*RDA is 1-2mg for adult
*Excess is stored in the liver, kidney and
muscles
*Also called Riboflavin
*SOURCES
*Animal source- Dried yeast, liver
kidney, egg yolk, dried skimmed milk
etc.
*Plant source- dark green vegetables
such as spinach, ewedu, bitter leaf,
whole wheat product etc.

38. *
*FUNCTIONS
*Essential for metabolism of CHO
*It is a co-factor in a number of enzymes
*It helps to keep skin and eyes healthy
*Cellular oxidation
*DEFICIENCY
*Ariboflavinosis – it is characterized by
angular stomatitis, glottis of the
tongue, misty eyes, cheilosis

40. *
*VITAMIN B3
*Also called Niacin
*Tryptophan is its precursor
*It is metabolized into 2 methylated
derivatives namely N-methyl-
nicotinamide and N-methyl pyridones
*RDA in adult is 8.8mg

41. *
*SOURCES
*Animal sources- liver, poultry, fish,
lean meat, beef, heart and kidney
*Plant sources- whole grains, brown
bread, groundnut, beans, yeast
*FUNCTIONS
*It is essential for CHO metabolism
*DEFICIENCY
*Pellagra- it is characterized by 4Ds,
glottis, stomatitis

43. *
*VITAMIN B6
*Also called pyridoxine
*Exists in 3 forms( pyridoxine,
pyridoxal, pyridoxamine
*Not easily destroyed by heat
*RDA in adult is 1.5-2mg
*SOURCES
*Animal sources- liver meat, milk,
egg yolk, fish

44. *
*Plant sources- legumes, cereals, yeast,
unpolished rice, fresh vegetables and
bananas
*FUNCTIONS
*It plays part in the metabolism of CHO,
Protein and fats
*Has specific role in metabolism of
tryptophan
*DEFICIENCY
*It is rare but includes nervous
disturbances such as irritability,
insomnia, muscular weakness, fatigue
and convulsion

45. *
*FOLATE
*Also called folacin/folic acid
*It is absorbed from the proximal part of
the small intestine
*SOURCES
*Fresh green leafy vegetables, whole
grains, nuts, liver and kidney
*FUNCTIONS
*Important in the synthesis of nucleic
acids
*Essential for normal development of
blood cells

46. *
*DEFICIENCY
*Deficiency are commonly found in
pregnancy and lactation
*It results in megaloblastic anemia,
glottis, cheilosis, GIT disturbances
such as diarrhea, distension and
flatulence
*Severe deficiency may cause
infertility or sterility

47. *
*VITAMIN B12
*Also called cyanocobalamin
*Absorption requires intrinsic factor
from the stomach
*Relatively heat stable
*Stored in the liver
*SOURCES
*Liver, kidney, meat, fish, egg, milk
*Also synthesized by bacteria in the
colon

48. *
*FUNCTIONS
*It works with folate in the synthesis
of DNA
*Plays role in the synthesis of fatty
acids in myelin
*DEFICIENCY
*It is rare
*Megaloblastic anemia

49. *
*VITAMIN C
*Also called ascorbic acid
*It is the most sensitive to heat
*SOURCES
*Fresh fruits and vegetables, pulses
*Traces are found in fresh meat and
fish
*FUNCTIONS
*Important in tissue oxidation

50. *
*Needed for collagen
formation(matrix for blood vessels
and connective tissues, bone and
cartilages)
*Facilitates the absorption of iron
*DEFICIENCY
*Scurvy – swollen and bleeding gum,
subcutaneous bruising or bleeding
into skin or joints, delayed wound
healing, anemia and weakness

52. *
*MINERALS
*More than 50 are found in human body
*They are required for growth, repair
and regulation of vital body functions
*They are liberated during oxidation
*They can be divided into major
minerals (sodium, potassium and
magnesium), trace elements ( iron,
iodine, fluorine, zinc, copper, cobalt,
etc)

53. *
*CALCIUM
*It constitute 1.5-2% of the body
weight of an adult
*Equilibrium in calcium in the blood
and skeleton is maintained by the
interaction of Vit.D, parathyroid
hormone and calcitonin
*RDA in adult is 800mg-1g
*Requirement increases during
pregnancy and lactation

54. *
*30% of ingested calcium is used by
the body while 70% is excreted
*Phytic acids prevents its absorption
*SOURCES
*Best natural sources are milk and its
products, eggs and fish, land snail,
dark green vegetables, millet etc.
*FUNCTIONS
*Needed for the development of
bones and teeth

55. *
*Required for blood coagulation
*Aids the contraction of muscles
*Transformation of light to electrical
impulses in the retina
*Metabolism of enzymes and
hormones
*Keeps membranes of cells intact

56. *
*DEFICIENCY
*Rickets –softening and weakening of
bones and teeth, retardation of
growth.

57. *
*ASSIGNMENT
*IRON, IODINE AND FLUORINE.
*Water

58. “Accept responsibility
for your life. Know that
it is you who will get
you where you want to
go, no
one else.” – Les Brown
“Just know, when you
truly want success,
you’ll
never give up on it. No
matter how bad the
situation may get.”