What is the treatment for rickets?

Treatment of Rickets

The primary treatment for rickets is vitamin D supplementation with a loading dose of 50,000 IU weekly for 8-12 weeks, followed by maintenance of 400-1000 IU daily, along with calcium supplementation of at least 1000 mg elemental calcium daily divided into 2-3 doses. 1

Diagnosis and Classification

Before initiating treatment, it's essential to determine the type of rickets:

Diagnostic Tests

• Serum calcium, phosphate, alkaline phosphatase (ALP), 25-hydroxyvitamin D, and parathyroid hormone (PTH)
• Urinary calcium and phosphate with calculation of TmP/GFR
• Radiographs of affected bones

Types of Rickets

1. Nutritional rickets: Low 25-hydroxyvitamin D, low/normal calcium, low phosphate, elevated ALP and PTH
2. X-linked hypophosphatemic rickets: Normal 25-hydroxyvitamin D, normal calcium, low phosphate, low TmP/GFR, elevated FGF23

Treatment Algorithm

For Nutritional Rickets (most common)

1. Vitamin D supplementation:

   • Loading dose: 50,000 IU weekly for 8-12 weeks 1
   • Maintenance: 400-1000 IU daily for infants and children 1

2. Calcium supplementation:

   • Minimum 1000 mg elemental calcium daily, divided into 2-3 doses 1
   • Adequate dietary calcium is necessary for response to vitamin D therapy

3. Special considerations:

   • Premature infants and exclusively breastfed infants with dark skin are at higher risk 2
   • Low-sodium diet to reduce calciuria 1

For X-linked Hypophosphatemic Rickets

1. Phosphate supplementation:

   • 20-60 mg/kg/day of elemental phosphorus divided into 4-6 doses 3
   • Do not exceed 80 mg/kg/day to prevent gastrointestinal discomfort 3

2. Active vitamin D:

   • Initial dose of calcitriol: 20-30 ng/kg body weight daily or
   • Alfacalcidol: 30-50 ng/kg body weight daily 3
   • For patients >12 months: can start empirically at 0.5 μg daily of calcitriol or 1 μg of alfacalcidol 3

3. Frequency of phosphate administration:

   • 4-6 times daily in young patients with high ALP levels 3
   • Can be lowered to 3-4 times daily when ALP normalizes 3

Monitoring

Short-term Monitoring

• Serum calcium, phosphate, ALP, and PTH every 2-4 weeks initially
• Clinical assessment of symptoms and bone deformities
• Urinary calcium excretion to prevent hypercalciuria

Long-term Monitoring

• Growth velocity and height
• Radiographs to assess healing
• Renal ultrasonography to monitor for nephrocalcinosis in patients on phosphate supplements 3

Important Considerations

• Therapeutic dose adjustment: Readjust as soon as there is clinical improvement 4
• Caution with high doses: In vitamin D resistant rickets, the range between therapeutic and toxic doses is narrow 4
• Monitoring calcium levels: When high therapeutic doses are used, follow with frequent blood calcium determinations 4
• Drug interactions: Mineral oil interferes with absorption of vitamin D; thiazide diuretics may cause hypercalcemia in patients on vitamin D therapy 4

Prevention

• Vitamin D supplementation for all infants: 400 IU daily, especially for exclusively breastfed infants 2
• For pregnant women: 1500-2000 IUs daily if unable to obtain adequate vitamin D from sunlight and diet 2
• For lactating women: approximately 6400 IUs daily to provide enough vitamin D in breast milk 2

Remember that early diagnosis and treatment are crucial to prevent severe deformities that may require surgical intervention. The goal is to resolve biochemical abnormalities and prevent complications that affect quality of life.