- 1 What is Deficiency Diseases and What are the types of Deficiency Diseases?
- 1.1 Protein Deficiency Disease
- 1.2 Protein And Carbohydrate Deficiency Disease
- 1.3 Vitamin Deficiency Diseases
- 1.4 1. Deficiency of Vitamin A
- 1.5 2. Deficiency of Vitamin B1
- 1.6 3. Deficiency of Vitamin C
- 1.7 4. Deficiency of Vitamin D
- 1.8 Mineral Deficiency Diseases
- 1.9 1. Deficiency of Calcium
- 1.10 2. Deficiency of Iodine
- 1.11 3. Deficiency of Iron
Environmental science incorporates Biology Topics to understand environmental issues.
What is Deficiency Diseases and What are the types of Deficiency Diseases?
We have just learnt that the essential food nutrients required for our body are carbohydrates, fats, proteins, vitamins and minerals. If any one of these nutrients is in less quantity than required or missing altogether from our diet over a long period of time, then it can cause a disease (or disorder) in our body. Since this disease arises from the deficiency of nutrients (or lack of nutrients) in our food (or diet), it is called a deficiency disease. We can now say that : A disease which arises due to the lack of nutrients (like carbohydrates, fats, proteins, vitamins or minerals) in our diet over a long period of time, is called a deficiency disease. A deficiency disease is not caused in a day or two. It occurs when one (or more) nutrients are not present in our food over a long period of time, say for months together. We will now discuss the various types of deficiency diseases in somewhat detail.
Protein Deficiency Disease
The deficiency of proteins in the diet of small children causes a disease known as kwashiorkar. Kwashiorkar disease occurs in children of 1 to 5 years of age. Kwashiorkar develops when a mother stops feeding her child with breast milk due to the birth of another baby too soon. And after weaning (removing) from the protein-rich breast milk, the child from a poor family is given a diet consisting mainly of carbohydrates, having low protein content. Thus, kwashiorkar is a protein-deficiency disease. A child suffering from kwashiorkar is shown in Figure.
The main symptoms of protein deficiency in children (or the main symptoms of kwashiorkar disease in children) are the following :
- The hair of child changes colour and becomes red.
- The skin of child cracks and becomes scaly (or rough).
- The stomach of child becomes swollen and bulges out. Swelling of face and feet also takes place.
- The child has stunted growth (slow growth).
- The child has reduced resistance to infection.
- The child becomes weak, and irritable (chidchida).
Protein And Carbohydrate Deficiency Disease
The deficiency of proteins as well as carbohydrates in the causes a disease known as marasmus. Marasmus disease occurs in infants (or babies) of up to 1 year of age. Marasmus develops when infants below the age of one year are abruptly weaned away from breast milk and are subsequently given a less nutritive food which is deficient in proteins as well as carbohydrates. Such a food is inadequate for the normal growth and development of the child.
A child suffering from marasmus is shown in Figure.
The main symptoms of protein-carbohydrate deficiency in children (or the main symptoms of marasmus disease in children) are given below.
- The child becomes very lean and thin.
- The child is reduced to just skin and bones. The bones of the child show through the skin.
- The ribs of child look very prominent.
- The child cannot even move due to lack of energy.
- The growth of child stops completely.
- The child’s weight becomes very low for his age.
Vitamin Deficiency Diseases
Deficiency (or lack) of various vitamins in the human diet gives rise to a number of diseases or disorders. Some of the vitamin deficiency diseases are : Night blindness, Beri-beri, Scurvy and Rickets. We will now discuss the diseases caused by the deficiency of four vitamins : vitamin A, vitamin Bl7, vitamin C and vitamin D.
1. Deficiency of Vitamin A
The deficiency of vitamin A weakens our vision (or eyesight) in dim light. Due to this a person having deficiency of vitamin A cannot see properly in dim light (or at night). The inability of a person to see properly in dim light (especially at night), is called night blindness. Thus, the deficiency of vitamin A in the diet causes a disease known as night blindness. Severe deficiency of vitamin A over a long period of time can lead to total blindness.
2. Deficiency of Vitamin B1
The deficiency of vitamin B1 in food causes a disease known as beri-beri. The symptoms of vitamin B1 deficiency (or symptoms of beri-beri disease) are as follows : The muscles of the person become very weak and he has very little energy to do work. The person may suffer heart failure or become paralysed and then die.
3. Deficiency of Vitamin C
The deficiency of vitamin C causes a disease known as scurvy. The symptoms of vitamin C deficiency (or symptoms of scurvy disease) are: bleeding from the gums, loosening of teeth, and wounds do not heal easily (see Figure).
4. Deficiency of Vitamin D
The deficiency of vitamin D in the diet of small children causes a disease known as rickets. A child suffering from rickets has bow legs (bent legs) and a pigeon-type chest (see Figure). Actually, vitamin D helps in absorbing calcium mineral in the body which makes the bones (and teeth) strong. When there is deficiency of vitamin D, then the bones of the child remain ‘soft’ due to inadequate absorption of calcium from food. These soft bones bend easily under the child’s own body weight. In addition to the weak bones (or soft bones), the deficiency of vitamin D also leads to poor teeth formation. As we will study after a while, rickets is also caused by the deficiency of calcium in the diet.
Mineral Deficiency Diseases
Deficiency (or lack) of various minerals in the human diet also gives rise to a number of diseases or disorders. Some of the mineral deficiency diseases are : Rickets, Cretinism, Goitre and Anaemia. We will now discuss the diseases caused by the deficiency of three minerals : calcium, iodine and iron, one by one.
1. Deficiency of Calcium
When a child is born, its bones are soft. For the bones to become hard, calcium compounds must be supplied. If a child does not get sufficient amount of calcium, its bones remain soft and bend under the weight of its own body. This is called rickets. Thus, the deficiency of calcium in the diet of children causes a disease called rickets. The main symptoms of rickets are : bow legs (bent legs), and pigeon-type chest. The deficiency of calcium also leads to poor growth of teeth in children. Please note that rickets is a children’s disease which is caused by the deficiency of vitamin D as well as by the deficiency of calcium in the diet. Deficiency of calcium in adults causes brittle bones and teeth (which can break easily).
2. Deficiency of Iodine
The deficiency of iodine mineral in the diet can cause two diseases : cretinism and goitre. The deficiency of iodine in the diet of children causes a disease known as cretinism (cretinism means feeble-mindedness). The main symptoms of iodine deficiency in children (or cretinism disease) are : retarded physical growth and mental disability.
The deficiency of iodine in the diet of an adult person causes a disease called goitre. Goitre is the abnormal enlargement of thyroid gland situated in our neck. This enlargement of the thyroid gland is caused by the deficiency of iodine. The main symptom of iodine deficiency (or goitre disease) is that the neck of the person appears to be swollen (see Figure).
The goitre disease is more common in hilly areas because the ‘drinking water’ and ‘food’ grown in such areas are poor in iodine. The goitre disease does not occur in coastal areas (sea-side areas) because coastal people eat a lot of sea food (like sea fish) which contains good amount of iodine. The most common source of iodine mineral in our homes is the ‘iodised salt’ used in cooking food.
3. Deficiency of Iron
Iron mineral is necessary for making haemoglobin present in our red blood cells. Deficiency of iron results in the blood containing too little haemoglobin. The function of haemoglobin is to carry oxygen in our body. Due to deficiency of haemoglobin (caused by lack of iron), the blood of a person is not able to carry sufficient oxygen to all the body cells to meet their requirement of oxidation of food and production of energy. This leads to anaemia. Anaemia is a disease in which the level of haemoglobin in the blood is less than normal, reducing the oxygen-carrying capacity of blood. Thus, the deficiency of iron in the diet leads to a disease called anaemia. The main symptoms of iron deficiency (or anaemia disease) are : The person looks pale, feels very weak, tires easily, and loses weight. His nails also turn white.
A balanced diet is made by taking a number of different foods which together supply all the essential nutrients like carbohydrates, fats, proteins, vitamins, and minerals to our body in the required amounts. So, if all of us eat a balanced diet, then there will be no shortage of any nutrient in our body and we will not suffer from any deficiency disease. Thus, all the deficiency diseases can be prevented by eating a balanced diet.