
Iodised salt can prevent iodine deficiency
ZIMSEC O Level Combined Science Notes: Deficiency Diseases
- A person might suffer from a deficiency disease if their diet lacks certain essential minerals and vitamins
- Two essential minerals and vitamins are:
- Iodine and
- Vitamins
Iodine

Goitre is a sign of iodine deficiency. Image credit betacharibletrust.org
- Is a naturally occurring mineral element
- However some people do not get it in enough quantities naturally
- Iodine is required by the thyroid gland found in the neck
- As part of the body’s metabolism in order to make a substance known as thyroxine which regulates growth and development
Symptoms of iodine deficiency
- In children there might be stunted physical and mental growth
- Adults might develop a goitre
- A goitre is a swelling of the thyroid gland.
- In children mental development might slow down their physical and mental development
- Resulting in children referred to as cretins
Overcoming iodine deficiency
- This can be overcome by using iodised salt
Vitamin A
- Is found in foods like fresh vegetables and liver
Symptoms of Vitamin A deficiency
- Poor development of the trachea lining
- This results in opportunistic infections of the trachea and bronchi
- Poor night vision/Night blindness
Overcoming the deficiency
- Eating food rich in vitamin A
- Such foods include dairy produce (cheese, milk, ice cream etc), carrots, cabbage and tomatoes
NB All these deficiency symptoms and others can be avoided by eating a balanced diet.
To access more topics go to the Combined Science Notes page.
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