Q.Goitre — an enlargement of the thyroid gland — is caused by the dietary deficiency of:

Goitre, which is an enlargement of the thyroid gland, occurs when the body does not receive enough iodine through the diet. Iodine is an essential micronutrient required for the synthesis of thyroid hormones, primarily thyroxine. These hormones regulate metabolism, growth, and development.

When there is an insufficient supply of iodine, the thyroid gland cannot produce adequate amounts of thyroid hormones. To compensate for this deficiency and try to capture more iodine from the bloodstream, the thyroid gland enlarges, leading to the characteristic swelling known as goitre.

Let's look at why the other options are incorrect:

• (a) Iron: Iron deficiency is a common cause of anemia, a condition where the blood lacks healthy red blood cells. It does not cause goitre. …

The thyroid gland, located in the neck, plays a vital role in regulating metabolism, growth, and development by producing thyroid hormones, primarily thyroxine. For the synthesis of these crucial hormones, the thyroid gland requires a sufficient supply of iodine, a trace mineral obtained through diet.

When there is an insufficient intake of iodine, the thyroid gland cannot produce enough thyroid hormones. In an attempt to compensate for this deficiency and absorb more iodine from the bloodstream, the thyroid gland begins to enlarge. This enlargement of the thyroid gland is known as goitre.

Let's examine the given options:

• (a) Iron: Iron is an essential mineral primarily involved in the formation of hemoglobin, which carries oxygen in the blood. Its deficiency leads to iron-deficiency anemia, characterized by fatigue, weakness, and pallor. Iron deficiency does not cause goitre.

• (b) Calcium: Calcium is crucial for strong bones and teeth, muscle contraction, nerve function, and blood clotting. Its deficiency can lead to conditions like osteoporosis (weak bones) and rickets in children. Calcium deficiency does not cause goitre. …