In adults, osteomalacia and in children, rickets are caused by the deficiency of which vitamin?

MP CHO -2019 (Shift-1)

Applied Nutrition & Dietetics

Easy

Appeared in: MP CHO -2019 (Shift-1)

Explanation

Vitamin D is essential for the absorption of calcium and phosphorus from the intestines, which are the primary building blocks of bone.
A deficiency in Vitamin D leads to decreased absorption of these minerals, resulting in hypocalcemia and hypophosphatemia.
To compensate, the body increases parathyroid hormone (PTH) levels, which can maintain calcium levels by resorbing it from bones, but the underlying lack of minerals prevents proper bone formation.
In children, this results in rickets, where growing bones become soft, weak, and deformed.
In adults, whose bones have stopped growing, it causes osteomalacia, characterized by the softening of bones, leading to pain and an increased risk of fractures.

Option A: Vitamin C deficiency causes scurvy, a disease affecting collagen synthesis. This leads to issues with connective tissues, resulting in symptoms like bleeding gums, poor wound healing, and joint pain, not the primary bone mineralization defects seen in rickets and osteomalacia.
Option C: Vitamin A deficiency primarily affects vision, the immune system, and epithelial cell integrity. Its deficiency leads to conditions like night blindness (nyctalopia) and xerophthalmia (dry eyes), not bone-softening diseases.
Option D: Vitamin E is a fat-soluble antioxidant. Its deficiency is rare in humans but can lead to neurological problems (e.g., spinocerebellar ataxia, peripheral neuropathy) and hemolytic anemia. It is not directly involved in bone mineralization.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Vitamin Deficiency and Bone Health as background academic context rather than a clinical decision trigger.
Nurses play a crucial role in patient education regarding the prevention of Vitamin D deficiency. This includes advising on adequate, safe sun exposure and dietary sources like fatty fish, fortified milk, and egg yolks.
Screening for deficiency is vital in high-risk populations, such as the elderly, individuals with malabsorption syndromes (e.g., Crohn's disease), and those with limited sun exposure (e.g., institutionalized individuals, people who wear extensive clothing).
Nurses administer Vitamin D supplements as prescribed and monitor for therapeutic effects (e.g., reduced bone pain) and signs of toxicity (hypercalcemia), which can include nausea, vomiting, and confusion.

How to Approach the Question

First, identify the key terms in the question: 'osteomalacia' in 'adults' and 'rickets' in 'children'.
Recognize that both are well-known bone disorders.
Recall the fundamental physiology of bone health, specifically the roles of calcium, phosphorus, and the primary vitamin that regulates their absorption.
Systematically evaluate each option's primary function and deficiency disease: Vitamin C (scurvy/collagen), Vitamin D (bone mineralization), Vitamin A (vision/epithelial), and Vitamin E (antioxidant/neurological).
Conclude that Vitamin D is the only vitamin directly responsible for regulating calcium and phosphate for bone mineralization, making its deficiency the cause of both rickets and osteomalacia.

Concept Tested & Keywords

Q6UKl5wVNKCkBWnpUcMepc

E6 Textbook of Biochemistry for medical StudentsDM Vasudevan Part 2 — Subpart A (pp 1-239 of 478) p. 126-128

E6 Pathology- ROBBINS & COTRAN PATHOLOGIC BASIS OF DISEASE 10TH Ed p. 446-448

E6 Parks TextBook of Preventive & Social Medicine part 2 — Subpart A (pp 1-232 of 464) p. 152-154