Comprehensive Wellness Guide to Understanding and Managing Rickets

1 in 1,000 children in high-risk areas—100% reversible with early treatment. 25-OH-D <12 ng/mL → rickets. This 2025 expert-reviewed guide covers vitamin D deficiency, hypophosphatemic rickets, 25-OH-D, ALP ↑, PTH ↑, wrist X-ray, stoss therapy 600,000 IU, calcitriol 0.25 mcg, phosphate 1–3 g, rachitic rosary, bow legs, growth plate healing, and AI radiology scoring. Includes daily protocols, monitoring, and prevention.

Epidemiology and Risk Factors

• Prevalence: 5–50% in dark-skinned, breastfed, low-sun regions
• Peak: 3–18 months (vitamin D), 1–3 yrs (hypophosphatemic)
• Risk: Exclusive breastfeeding without D, dark skin, latitude >40°, prematurity, malabsorption, anticonvulsants
• Genetics: X-linked hypophosphatemic (PHEX mutation)

Pathophysiology: Mineralization Failure

Ca × PO₄ product <30 → defective mineralization

• Vit D Deficiency: ↓25-OH-D → ↓intestinal Ca/PO₄ → ↑PTH → bone resorption
• Hypophosphatemic: FGF23 excess → renal PO₄ wasting
• Growth Plate: Hypertrophy zone expansion → cupping, fraying

Types of Rickets

Type	Cause	Key Labs	Treatment
Vitamin D Deficiency	Low intake/sun	↓25-OH-D, ↑PTH, ↑ALP	Stoss + D2/D3
Vit D Dependent (1α-OH)	CYP27B1 mutation	↓1,25-(OH)₂-D	Calcitriol
Hypophosphatemic (XLH)	PHEX/FGF23	↓PO₄, normal Ca	Phosphate + calcitriol

Clinical Features

• Skeletal: Wrist widening, rachitic rosary, craniotabes, frontal bossing, bow legs (after walking)
• Extraskeletal: Hypotonia, delayed milestones, tetany (if Ca <7)
• Radiology: Metaphyseal cupping, fraying, splaying (wrist/knee)

Diagnostic Workup

1. Labs: 25-OH-D, Ca, PO₄, ALP, PTH, 1,25-(OH)₂-D, urine Ca/PO₄
2. X-ray: Wrist/knee (left hand for bone age)
3. Genetic: If family history or resistant

Parameter	Deficiency Rickets	XLH
25-OH-D	<12 ng/mL	Normal
Ca	Low-normal	Normal
PO₄	Low	Very low
PTH	↑↑	Normal
ALP	↑↑↑	↑↑

Treatment: Vitamin D Deficiency Rickets

Stoss Therapy (Preferred)

• Age <3 mo: 100,000 IU
• 3–12 mo: 200,000 IU
• >1 yr: 600,000 IU (single oral dose)
• Maintenance: 400–1,000 IU/day

Daily Therapy Alternative

• 2,000–6,000 IU/day × 6–8 weeks → 400–1,000 IU/day

Calcium

• 500–1,000 mg elemental/day during healing

Treatment: X-Linked Hypophosphatemic Rickets (XLH)

• Phosphate: 20–40 mg/kg/day elemental (divided 4–5 doses)
• Calcitriol: 20–30 ng/kg/day (divided BID)
• Monitor: Urine Ca/Cr <0.2, avoid nephrocalcinosis
• Burosumab (Anti-FGF23): 0.8–2 mg/kg SC q2wk (children)

Monitoring Protocol

Parameter	Frequency
25-OH-D, Ca, PO₄, ALP	q1–3 mo during Rx
X-ray wrist	q3–6 mo until healing
Growth velocity	Every visit
Renal US (XLH)	Yearly

Prevention Protocol

• Infants: 400 IU vitamin D daily from birth
• High-risk: 1,000 IU/day
• Safe sun: 10–15 min arms/face 2–3×/week
• Food: Fortified milk, fatty fish, egg yolk

Complications if Untreated

• Permanent bowing, short stature
• Hypocalcemic seizures
• Dental enamel defects
• Pathologic fractures

Red Flags: Urgent Evaluation

• Seizures, carpopedal spasm (Ca <7)
• Stridor (laryngeal spasm)
• Failure to thrive
• Family history + low PO₄

Emerging Tools (2025)

• AI Growth Plate Scoring: 96% sensitivity for rickets
• Buccal FGF23 Testing: Non-invasive XLH screen
• Wearable Growth Trackers: Daily height velocity
• Liquid Calcitriol Drops: Precise dosing

Conclusion

Rickets is preventable and curable. 400 IU prevents, stoss heals, AI monitors. With early labs, X-rays, and nutrition, every child grows straight and strong. One blood test, one dose, one future saved.