Question

Goitre is caused by the deficiency of

• A. Iron
• B. Calcium
• C. Potassium
• D. Iodine

Answer 1

Answer:

D. Iodine

Iodine Deficiency and Goitre

Understanding Goitre:

• Goitre refers to the enlargement of the thyroid gland, a butterfly-shaped gland located at the base of the neck.
• This enlargement occurs when the thyroid gland grows larger than its normal size.

The Role of Iodine:

• Iodine is an essential mineral that the body cannot produce on its own; it must be obtained from the diet.
• The thyroid gland requires iodine to produce thyroid hormones, primarily thyroxine (T4) and triiodothyronine (T3).
• These hormones play a crucial role in regulating metabolism, growth, and development.

Mechanism of Goitre Development due to Iodine Deficiency:

• When there is a lack of iodine in the diet, the thyroid gland cannot produce sufficient amounts of thyroid hormones.
• In response to low hormone levels, the pituitary gland releases Thyroid Stimulating Hormone (TSH).
• TSH stimulates the thyroid gland to grow larger in an attempt to capture more iodine from the bloodstream and produce more hormones.
• This continuous stimulation leads to the hypertrophy (enlargement) and hyperplasia (increase in number of cells) of thyroid follicular cells, resulting in a visible goitre.

Sources of Iodine:

• The most common and effective source of iodine is iodized salt.
• Other dietary sources include seafood (fish, shellfish), dairy products, and eggs.
• Iodine content in plant-based foods varies depending on the iodine concentration in the soil where they are grown.

Geographical Prevalence:

• Iodine deficiency disorders (IDD) are more common in regions where the soil and water have low iodine content, such as mountainous areas and inland regions far from the sea.
• Public health initiatives, like mandatory iodization of salt, have significantly reduced the incidence of goitre in many parts of the world.

Other Related Deficiency Diseases:

• Severe iodine deficiency during pregnancy can lead to cretinism in infants, characterized by severe mental retardation and stunted physical growth.
• Iodine deficiency can also cause hypothyroidism, a condition where the thyroid gland doesn't produce enough hormones, leading to symptoms like fatigue, weight gain, and depression.