What nutrient deficiency causes goiter?

RRB Nsg. Superintendent 21 July 2019 (shift 1st)

Applied Nutrition & Dietetics

Easy

Appeared in: RRB Nsg. Superintendent 21 July 2019 (shift 1st)

Explanation

Iodine is an essential mineral required by the thyroid gland for the synthesis of thyroid hormones (T3 and T4).
A deficiency in dietary iodine leads to decreased production of these hormones.
In response to low thyroid hormone levels, the pituitary gland increases the secretion of Thyroid-Stimulating Hormone (TSH).
Prolonged stimulation by TSH causes the thyroid gland to enlarge in an attempt to trap more iodine, resulting in a goiter.

Option B: Protein deficiency does not cause goiter. Its primary manifestation is kwashiorkor, characterized by edema, muscle wasting, and growth failure.
Option C: Calcium deficiency is linked to bone and neuromuscular disorders, not thyroid enlargement. It leads to conditions like osteoporosis, rickets, and tetany.
Option D: Carbohydrate deficiency primarily leads to an energy deficit and ketosis, as the body starts breaking down fats for fuel. It does not affect the thyroid gland in a way that causes goiter.

Visual 1: Diagram: A flowchart illustrating the hormonal feedback loop (Hypothalamus-Pituitary-Thyroid axis) and showing how a lack of iodine interrupts the process, leading to increased TSH and goiter.
Visual 2: Image: A clinical photograph showing a person with a visible goiter to help students recognize the physical manifestation.
Visual 3: Infographic: A map of the world highlighting regions where iodine deficiency is endemic ('goiter belt').

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Nutrient deficiencies and their associated diseases as background academic context rather than a clinical decision trigger.
A key public health measure in India and worldwide is the iodization of salt, which has dramatically reduced the prevalence of goiter.
Nurses play a vital role in educating patients and communities about the importance of using iodized salt to prevent Iodine Deficiency Disorders (IDD).
When assessing a patient with a neck swelling, a nurse should inquire about dietary habits, place of origin (endemic area), and symptoms of hypothyroidism or hyperthyroidism.

How to Approach the Question

Identify the key term in the question, which is 'goiter'.
This is a factual recall question. Access your knowledge of nutrition and endocrine disorders.
Recall the primary function of the thyroid gland and the essential nutrient it needs to produce hormones.
Evaluate each option: Iodine is directly used by the thyroid. Protein, calcium, and carbohydrates have different primary roles and deficiency diseases.
Select the nutrient that is directly linked to thyroid hormone synthesis and whose deficiency logically leads to the compensatory enlargement of the gland.

Concept Tested & Keywords

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