What is the cause of Osteomalacia in adults?

Bihar CHO - 2021

Medical Surgical Nursing

Easy

Appeared in: Bihar CHO - 2021

Explanation

Osteomalacia is the softening of bones in adults due to defective mineralization.
The most common cause is a severe deficiency of Vitamin D.
Vitamin D is essential for the intestinal absorption of calcium and phosphorus, which are the primary minerals required for bone hardening.
Without adequate Vitamin D, the newly formed bone matrix (osteoid) fails to mineralize, leading to weak, painful bones that are prone to fractures.

Option A: Vitamin A deficiency primarily affects vision, leading to conditions like night blindness (nyctalopia) and dry eyes (xerophthalmia). It is not associated with bone mineralization.
Option B: Deficiency of B-complex vitamins causes a wide range of conditions, such as beriberi (B1), pellagra (B3), and pernicious anemia (B12), but it does not directly cause defective bone mineralization.
Option C: Vitamin C (ascorbic acid) deficiency leads to scurvy, a disease of impaired collagen synthesis. This results in fragile capillaries, bleeding gums, and poor wound healing, but not the primary mineralization defect seen in osteomalacia.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Cause of Osteomalacia as background academic context rather than a clinical decision trigger.
Nurses play a crucial role in identifying at-risk populations for Vitamin D deficiency, including the elderly, homebound individuals, those with malabsorption syndromes (e.g., celiac disease), and people with limited sun exposure.
Patient education is a key nursing intervention. This includes advising on safe sun exposure, dietary sources of Vitamin D (fatty fish, fortified milk), and the importance of adhering to prescribed supplements.
What if? If the patient has chronic kidney disease, they cannot convert Vitamin D to its active form (calcitriol). In this scenario, standard Vitamin D supplements are ineffective, and the patient requires treatment with active Vitamin D (calcitriol) to prevent renal osteodystrophy, a severe form of bone disease.

How to Approach the Question

First, identify the key term in the question: 'Osteomalacia'.
Recall the definition of osteomalacia, which is the softening of bones in adults.
Connect the condition to its underlying pathophysiology, which is defective bone mineralization.
Consider the role of different vitamins in the body. Recall that Vitamin D is essential for calcium and phosphorus absorption, the key minerals for bone health.
Evaluate the options provided. Eliminate vitamins A, B, and C by recalling the specific deficiency diseases they cause (e.g., night blindness, beriberi, scurvy).
Conclude that Vitamin D deficiency is the only option directly linked to impaired bone mineralization, and therefore is the cause of osteomalacia.

Concept Tested & Keywords

Qxj63HNHWMVo0tr2BgxOlZ

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 Medicine Davidson Principles Practice 24e p. 1069-1071