A 9-year-old child from a slum community presents with bilateral bowing of legs. X-rays show widened growth plates, cupped metaphyses, and cortical thinning. Serum calcium and phosphorus are both low, ALP is very high, PTH is elevated, and 25-OH vitamin D is undetectable. In addition to Vitamin D supplementation, which OTHER micronutrient is essential to co-administer to prevent hypocalcemic tetany and promote bone mineralisation?
- A Calcium ✓
- B Zinc
- C Magnesium
- D Phosphorus
Explanation
In nutritional rickets with hypocalcemia and severely low vitamin D, repletion with vitamin D alone drives rapid bone mineralisation, which can precipitate hypocalcemic tetany (hungry bone syndrome) if calcium intake is inadequate. Concurrent calcium supplementation (500–1000 mg elemental calcium/day for 3 months) is essential alongside vitamin D therapy. Dietary calcium deficiency is also an independent cause of rickets (calcium-deficiency rickets) especially in sub-Saharan Africa. Zinc deficiency can cause growth failure but does not cause rickets. Magnesium is relevant if severe hypomagnesemia impairs PTH secretion.
Reference: Ghai Essential Pediatrics, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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