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  1. Introduction to Science | Week 1
    4 Topics
    1 Quiz
  2. Family Health | Week 2
    6 Topics
    1 Quiz
  3. Family Health (Sanitation) | Week 3
    4 Topics
    1 Quiz
  4. Family Health (Nutrition) | Week 4
    8 Topics
    1 Quiz
  5. Drug and Substance Abuse | Week 5
    3 Topics
    1 Quiz
  6. Environmental Pollution: Air Pollution | Week 6
    3 Topics
  7. Soil pollution | Week 7
    2 Topics
  8. Water Pollution | Week 8
    4 Topics
    1 Quiz

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Based on the nutrients in food, food substances are classified into:

1. Protein.
2. Carbohydrates.
3. Fats and oil (lipids)
4. Vitamins.
5. Minerals.
6. Water.

Generally, all foods are categorized into:

1. Energy-giving food: Carbohydrates and Fats and Oil.

2. Bodybuilding food: Protein

3. Health preserving food: Vitamins and Minerals

Below is a list of different classifications of nutrients, their sources, functions and composition.

ProteinMeat, milk, fish, poultry, beans, eggs, cheese
Supports growth and maintains healthy body cells Carbon, hydrogen, oxygen, nitrogen, sulphur and phosphorus
Carbohydrates Cereal, potatoes yam, bread, maize, sugar
Provides main source of energy for the energyCarbon, hydrogen, oxygen
Fats and oilVegetable oil, butter, palm-oil, margarine Fats and OilsProvides energy for the body, it also keeps the body warmCarbon, hydrogen, oxygen
VitaminsLiver, carrots, oranges, grapes, milk, cheese, fruits
Protects the body against diseases, promotes chemical reaction in the body Varying in components e.g vitamin A, Vitamin E
Minerals Liver, meat, poultry, fish
Regulates the body’s metabolismPotassium, iron, calcium
Most food we eat contain water e.g fruits
Helps with body process such as digestion, makes up 60% of the human adult bodyHydrogen, oxygen

Vitamins: Promote chemical reactions in the body

The various types of vitamins, sources, functions, and effects of deficiency are seen below.  

of Deficiency 
1A (Retinol)Liver, eggs, milk,
fish, liver oil,
For healthy skin
and normal vision. 
Dry skin, night blindness.
2B complexYeast, palm wine,
beans, eggs,
For normal growth,
for normal working
of the heart and
nervous system.
Reduced growth, beriberi.
3C (Ascorbic acid)Citrus fruits e.g
oranges, tomatoes, guava, pawpaw,
green vegetables.
Maintenance of
connective tissue
bones, help to resist infections.
Slow healing of wounds, scurvy.
4D(Calciferol) Milk, egg yolk,
liver, fish liver oil.
Facilitates absorption of calcium and phosphorous
in the intestine, for
hardening of bones.
Rickets (poor bone and teeth formation)
5E (Tocopherol)Leafy vegetables, oils, e.g. palm oil, eggs.Required for the
proper function of
many organs in the body.
It is also an antioxidant. 
6.KGreen vegetables.Synthesis of blood
clotting factors.
Slow clotting of blood
leading to severe bleeding. 

Minerals regulate the metabolism of the body. Their sources, types and deficiency symptoms are written below:

Minerals SourcesFunctionsDeficiency symptoms 
1SodiumSalt, meat,
egg, milk.
for normal cell
kidney failure 
2Chlorine Salt.Maintains correct
osmotic pressure
of body fluids.
Muscle cramps
3PotassiumAll natural foods.Permeability, for
normal cell membrane.  
Loss of bone minerals, muscle paralysis 
4CalciumDiary products e.g.
milk, cheese, eggs, vegetables.
Bone formation, blood
clotting and
softening of bones.
5.Phosphorous Dairy products,
meat, beans,
Bone formation and
general metabolism 

6.MagnesiumLeafy vegetables,
nuts, seafood.
A major component
of bones.
Teeth muscle,
muscle contraction 
7IronLiver, egg, meat,
green vegetable. 
Formation of
haemoglobin in
red blood cells.
iodized table salts.
The body needs iodine to
make thyroid hormones.
These hormones control
the body’s metabolism and many other
important functions.
9.Fluorine Milk.Hardening of bones and teeth.Dental caries 

An excessive loss of water from the body is called dehydration measured with a calorimeter.

Factors that Determine Nutrients needs of an Individual:

1. Age.
2. Weight.
3. Sex.
4. The amount of physical exercise.

Specific health conditions such as pregnancy, breastfeeding, illness, or drug use, make unusual demands on the body and increases its need for nutrients.


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