Biology

Key Unit Competence
Discuss the roles of minerals and vitamins in diet

Learning objectives
At the end of this unit you be able to:
–– State the mineral requirements for bodily functions.
–– Identify the symptoms of mineral and vitamin deficiency.
–– Outline the need for consumption of minerals and vitamins in small amounts.
–– Organize a list of foods that are good sources of vitamins and mineral salts.
–– Recognize the signs and symptoms of scurvy, night blindness, goiter, and anaemia.
–– Differentiate between water soluble and lipid soluble vitamins.
–– Analyze one’s eating habits and suggest improvements
–– Appreciate the importance of a balanced diet in relation to health and economic prosperity.
–– Advocate for healthy feeding methods.

Introductory activity
1. From the different food stuffs in our community, make a list of food stuffs that are good sources of minerals and vitamins.
2. Using text books and other resources, make a list of e vitamins and mineral deficiency diseases

9.1 Mineral nutrients in humans
Activity 9.1
Use textbooks and internet to list mineral nutrients found in human diet Mineral nutrients are sometimes called mineral salts or just minerals. Mineral salts are essential nutrients that our body needs. They are called essential not because they are more important than other substances in our body but because our
bodiescannot produce them. They include the inorganic substances found in daily diet. They are dissolved in body fluids.

They are found in human body as ions (cations and anions). Organic food like proteins, carbohydrates and fats provide the body with carbon, hydrogen, oxygen, nitrogen, sulfur and phosphorus. Butthere are several more elements that the body needs and occur as salts in the food we eat. They constitute about 1% of an organism by weight. Even though they are required in a very small amount, they are nonetheless essential for body processes.

Some mineral nutrients are required by animals, plants, a few by both. Humans require a number of minerals for the good functions of their bodies. Those are: Calcium (Ca²⁺), phosphorus (H₂PO-₄), Nitrogen(NO-₃), Sulfur (SO²- ₄) Potassium (K⁺), Sodium (Na⁺), Iron (Fe²⁺ or Fe³⁺), Magnesium (Mg²⁺), Iodine (I-), Chloride (Cl^-), Manganese (Mn²⁺), Fluoride (F-), zinc (Zn²⁺), Cobalt (Co²⁺), Chromium (Cr²⁺ or Cr³⁺) and molybdenum (MoO^-₄)

Self-assessment 9.1
1. Outline ten mineral nutrients required in human diet.
2. Answer by true or false and justify your answer: “Minerals are called essential nutrients because they are more important than others”.

9.2 Classification of mineral nutrients
Activity 9.2
Iodized table salt is advised to prevent goiter. In 100g of table salt there is 99% of NaCl, and only 1% of iodine. Refer to the notes below to find the reason behind
this ratio.

The classification of minerals is based upon their requirement rather than on their relative importance. Mineral nutrients are needed in a precise small amount. The five major minerals needed in human body include calcium (Ca²⁺),phosphorus (H₂PO-₄), potassium (K⁺), sodium
(Na⁺) and magnesium (Mg²⁺). Mineral nutrients are grouped into two groups: the macronutrients
or major elements and the micronutrients or trace elements.
Macronutrient or major elements are minerals needed by humans in a relative large amount (greater than 200 mg/day). Their examples include nitrogen(NO₃-) , phosphorus (H₂PO^-₄), sulfur(SO²-₄) , calcium (Ca²⁺), sodium (Na⁺), chlorine (Cl^-), magnesium (Mg²⁺), and iron (Fe²⁺ or Fe³⁺).Micronutrients or trace elements are those which are needed in minute amount (a few parts per million). Examples
include manganese (Mn²⁺), iodine (I^-), zinc (Zn²⁺), molybdenum(MoO^- ₄)and fluorine (F-).

Self-assessment 9.2
1. Categorize mineral nutrients according to their amount in human body.
2. Distinguish the two categories of mineral nutrients needed by the human body.
3. From the minerals listed here, identify the five major minerals in the human body: Sulfur (S), Potassium (K), Sodium (Na), Iron (Fe), Magnesium (Mg), Iodine (I), Chloride (Cl), zinc (Zn), Cobalt (Co), chromium, Calcium (Ca), phosphorus (P), Nitrogen (N).

9.3 Sources, functions and deficiency symptoms of mineral nutrients in humans
Activity 9.3
Use your textbook to answer the following questions:
Hereunder is a variety of food stuffs: Banana, cassava, wholegrain, oranges, pumpkin, potato, beans, water melon, green leafy vegetables, poultry, eggs, liver, and milk. Choose the food stuffs which are good sources of minerals. Human body requires mineral nutrients to survive and to carry out daily functions
and processes. Minerals keep humans healthy and have key roles in several body functions. Humans receive minerals by eating plants that absorb minerals from the soil and by eating meat and other products from animals, which graze on plants. The deficiency of mineral nutrients results into body functional disorders and diseases. Most are found in the blood and cytoplasm of cells, where they assist basic functions. For example, calcium and potassium regulate nerve and muscle activity

Self-assessment 9.3
1. Match the mineral nutrients with its function
a. Iodine                              1. make bones hard
b. Fluorine                           2. maintains the immune system stronger
c. Phosphorus                     3. component of hemoglobin
d. Iron                                  4. prevents tooth decay
e. Copper                            5. used in synthesis of thyroid hormone (thyroxin)
2. In a tabular form, identify the major dietary sources, the functions in human bodies and the deficiency diseases of the following minerals: Ca, I, P, zinc, and Cu
3. Choose the best answer.
i. They are the minerals we need a lot in every day diet. How are they called?
a. Macronutrents
b. Micronutrients
c. Giant minerals
d. Monster minerals
ii. This mineral helps to build up strong teeth and bones. How is it called?
a. Calcium
b. Iron
c. Zink
d. potassium
iii. What are foods that are natural good source of iron?
a. Roast Beef
b. Macaroni and cheese
c. Baked beans
d. Water melon
iv. Select 2 that are natural good sources of calcium?
a. Milk and cheese
b. Whole-wheat bread
c. Iceburg lettuce
d. Scanned salmon
v. The mineral that helps in oxygen transport to lungs is?
a. calcium
b. iron
c. zinc
d. potassium
vi. Which foods are good sources of zinc?
a. Milk and cheese
b. Lamb and pork
c. Macaroni and cheese
d. Peanuts and lentils
vii. Bananas are great source of this mineral, which helps our muscles and nervous
system to maintain your right water levels. What is it called?
a. Calcium
b. Iron
c. Zinc
d. Potassium
viii. Which mineral is important and needed by our body to fight off infection?
a. Calcium
b. Iron
c. Zinc
d. Potassium
ix. Which of the following mineral are needed in large amount every day?
a. Zinc
b. Iron
c. Calcium
d. selenium
x. Which is the type of mineral that keep your nervous system health?
a. Calcium
b. Iron
c. Zinc
d. Potassium
4. From the diseases listed below, what are those caused by the deficiency of minerals?
Goiter, malaria, diabetes, rickets, beriberi, scaly skin, night blindness, anemia, impaired immunity, diarrhea

9.4 Vitamins and the classification of vitamins
Activity 9.4
Two students with different complains went to consult a medical doctor. Student A says to the doctor that whenever he/she bleeds whenever she /he brushes teeth. Student B doesn’t see well objects around him/her, The results from the doctor showed that they all have lack some vitamins.
1) What kind of vitamins that each student needs to take?
2) Use your student textbook to explain your answer
Like minerals, vitamins are also essential for the human body. They are required for metabolism, protection health and growth. Vitamins also assist in formation of hormones, blood cells and genetic material. Vitamins are directly absorbed from the small intestine into the blood stream. Water –soluble vitamins are absorbed in the ileum while fat-soluble vitamins are absorbed in jejunum. Features shared by all vitamins:

–– They are not digested or broken down for energy
–– They are not synthesized into the body structures
–– Most are rapidly destroyed by heat.
–– They are essential for good human health and needed in a very small amount
–– They are required for chemical reactions in cells, working in association with enzymes.

There are thirteen vitamins required by human body. They are classified by their solubility, whether they dissolve in water or in fats. Water-soluble vitamins including vitamins C and B complex, and fat-soluble vitamins including vitamins A, D, E and K (Table 9.2). Excess water- soluble vitamins are simply excreted in urine, while fatsoluble vitamins are stored in body fatty tissues to be used later if there is deficient
in diet. Excess intakes of these vitamins are stored in fatty tissues of the body, where they can build up to toxic levels, especially if they are taken improperly in supplements.

Table 9.2 Water-soluble and fat-soluble vitamins

Self-assessment 9.4
1. How many vitamins does the human body needs to function properly?
2. Describe the classification of vitamins.

9.5 Sources, functions and symptoms of vitamin deficiency
Activity 9.5
Here is a number of foodstuffs rich in vitamins.

From the list of provided food stuffs (Banana, cassava, wholegrain, oranges, pumpkin, potato, beans, water melon, green leafy vegetables, and milk). Can you give some foods that are good sources of vitamins?
Some vitamins, including some vitamin B complex and Vitamin K are produced by bacteria that normally live in the intestines, where they help to digest food. Vitamin D is synthesized in the skin when it is exposed to UV radiation in sunlight.

Vitamins and their derivative are coenzymes; note that a coenzyme is an organic molecule that combines temporaly with enzymes making them more efficient. For example, Niacin or vitamin B3 is an essential component of coenzymes NAD and NADP involved in lipid metabolism. It inhibits production of cholesterol and catabolism of triglyceride. Thiamin or vitaminB1 is a coenzyme for many different enzymes that break complex molecules such as carbohydrates to produce ATP.

Thiamin deficiency results into Beriberi anemia and stunted growth in children. Vitamin K is an essential coenzyme for synthesis of several blood clotting factors. Several vitamins, including vitamins C and E, act as antioxidants. An antioxidant is a compound that neutralizes chemicals called free radicals. Free radicals are produced naturally during cellular activities and may cause some types of cancer. Neutralizing free radicals makes them harmless.

The table: 9.3. The major dietary sources, functions and possible symptoms of vitamin deficiency

Many vitamin supplements are available in the market. However, it is always advisable to obtain them from their natural sources by eating food rich in vitamins daily. Possible symptoms of vitamins deficiency are shown by the following pictures:

End of unit assessment 9
1. Choose a mineral which is an electrolyte and is found in almost every food. It helps to lower blood pressure.
a. Zinc
b. Potassium
c. Calcium
d. Iron

2. choose a mineral which helps to make our blood vessels, tendons, and nerves strong.
a. Iron
b. Magnesium
c. Chromium
d. Copper

3. The following vitamins are part of Niacin and Thiamin minerals
a. Vitamins
b. Vitamins
c. Vitamins
d. Vitamins

4. Vitamin C is required for the production and maintenance of:
a. Collagen
b. Hormone
c. Ascorbic Acid
d. Red Blood Cells

5. Vitamin C deficiency is called:
a. Scurvy
b. Cold
c. Cancer
d. Rickets

6. Which of the following is a function of Vitamin A in the body?
a. Vision, bone and body growth
b. Immune defenses, maintenance of body linings and skin
c. Normal cell development and reproduction
d. All of the above

7. Common food sources of Vitamin A are:
a. Milk, eggs, butter, cheese, cream, and liver
b. White sugar, honey, and sugar cane
c. Broccoli, apricots, Cantaloupe, Carrots, Sweet potato, Spinach
d. Both a and c

8. Which of the following is a function of Vitamin B-12?
a. Influences the cells that build bone tissue
b. Is essential to the formation of bone
c. Helps to maintain acid-base balance
d. Maintains the sheaths that surround and protect nerve fibers

9. Vitamin B-12 deficiency caused by lack of intrinsic factor is called:
a. Pernicious anemia
b. Poor circulation of the red blood cells
c. Beriberi
d. None of the above

10. What groups of people need additional Vitamin K?
a. Premature newborns
b. People who do not have enough bile to absorb fat
c. Both A and B
d. None of the above answers

11. A common function of Thiamin, Riboflavin and Niacin is that:
a. They all are used in synthesis of blood clotting proteins
b. They all work as a part of a coenzyme used in energy metabolism
c. They all help to strengthen blood vessel walls
d. They are used to stabilize cell membranes
12. The vitamin Folate works together with ______________ to produce new red blood cells.
a. Vitamin D
b. Vitamin A
c. Vitamin B-12
d. None of the above

13. Which of the following is a function of Vitamin B-12?
a. Red blood cell formation
b. Myelin sheath that protects nerve biers
c. Vision
d. Both A and B

14. Vitamin C helps in maintenance and repair of collagen which:
a. Forms the base for all connective tissue in the body
b. Aids in digestive processes
c. Promotes good eyesight
d. Prevents PMS symptoms

15. Which of the following is not a function of Vitamin D?
a. Acts like a hormone
b. Stimulates maturation of cells
c. Maintains calcium cells
d. Builds tissue

16. Some food sources of Vitamin D are:
a. Fruits and vegetables
b. Salmon and egg yolks
c. Butter and fortified milk
d. Both B and C.

17. Humans obtain vitamins from natural sources such as vegetables, fruits,
meat, fish and dairy products. What are the two vitamins that are not provided
by fruits and vegetables?

18. What would you advise someone starting to have symptoms of?
a. Scurvy
b. Rickets
c. Teeth decay
d. Heart failure
e. Pernicious anemia