Milk Allergy and Rickets Risk: Nutritional Management in Children

Milk allergy does not directly cause rickets, but dietary elimination of dairy without adequate substitution increases risk of vitamin D and calcium deficiency → impaired bone mineralization.

Pathophysiology

• Cow's milk protein allergy (CMPA) → elimination diet.
• Dairy = primary dietary source of calcium and vitamin D (fortified) in children.
• Inadequate replacement → hypocalcemia → secondary hyperparathyroidism → rickets (growth plate mineralization failure).

Clinical Features of Rickets

• Bowing of legs (genu varum/valgum), wrist/ankle widening, rachitic rosary (costochondral beading), frontal bossing, delayed closure of fontanelle.
• Hypocalcemic seizures, tetany, muscle weakness.
• Radiographs: cupping, fraying, widening of metaphyses.

Prevention and Management

• Dietitian involvement at CMPA diagnosis.
• Calcium: 700 mg (1–3 yr), 1000 mg (4–8 yr), 1300 mg (9–18 yr) — from fortified plant milks, tofu, canned fish with bones, leafy greens, supplements.
• Vitamin D: 600 IU/day (400–1000 IU); target 25(OH)D >30 ng/mL.
• Hypoallergenic formula: Extensively hydrolyzed or amino acid-based (infants).
• Monitoring: 25(OH)D, calcium, phosphorus, ALP, PTH q6–12mo.

Other Rickets Causes

• Malabsorption (celiac, IBD, cystic fibrosis).
• Renal tubular disorders (Fanconi, hypophosphatemic rickets).
• Genetic (VDR mutations, CYP27B1).