What is the treatment for vitamin D deficiency?

Treatment of Vitamin D Deficiency

The recommended treatment for vitamin D deficiency is supplementation with ergocalciferol (vitamin D2) or cholecalciferol (vitamin D3), with dosing based on the severity of deficiency: 800-1,000 IU daily for mild insufficiency (15-20 ng/mL), 50,000 IU weekly for 4-8 weeks for moderate deficiency (5-15 ng/mL), and individualized treatment under close monitoring for severe deficiency (<5 ng/mL). 1

Diagnosis and Classification

Before initiating treatment, vitamin D status should be assessed by measuring serum 25-hydroxyvitamin D [25(OH)D] levels:

• Severe deficiency: <5 ng/mL (<12.5 nmol/L)
• Mild-moderate deficiency: 5-15 ng/mL (12.5-37.5 nmol/L)
• Insufficiency: 16-30 ng/mL (40-75 nmol/L)
• Target range: 30-80 ng/mL (75-200 nmol/L) 1

Treatment Algorithm

For General Population:

1. Mild insufficiency (15-20 ng/mL):

   • 800-1,000 IU vitamin D3 daily 1, 2

2. Moderate deficiency (5-15 ng/mL):

   • 50,000 IU vitamin D2 or D3 weekly for 4-8 weeks 1, 2
   • Then transition to maintenance dose of 800-1,000 IU daily 2

3. Severe deficiency (<5 ng/mL):

   • Requires individualized treatment under close monitoring 1
   • May require higher doses and longer treatment duration
   • Cumulative dose of at least 600,000 IU administered over several weeks 3

Special Populations:

• Elderly (≥65 years): Minimum 800 IU daily 1
• Dark-skinned or veiled individuals: 800 IU daily 1
• Institutionalized individuals: 800 IU daily 1
• Obesity: 2-3 times higher doses (up to 7,000 IU daily) 1
• Malabsorption syndromes: Minimum 2,000 IU daily or weekly regimens 1
• Chronic kidney disease: Specialized approaches with annual monitoring 1

Monitoring and Safety

• Recheck 25(OH)D levels 3-4 months after initiating therapy 1
• Monitor serum calcium and phosphorus during supplementation
• Vitamin D toxicity is rare but can occur with doses >10,000 IU daily for extended periods 1
• Signs of toxicity include hypercalcemia, kidney stones, and soft tissue calcification 4
• Avoid single large doses of 300,000-500,000 IU as they may increase fall and fracture risk 3

Important Considerations

• Cholecalciferol (vitamin D3) appears to have higher bioefficacy than ergocalciferol (vitamin D2) 1
• Adequate calcium intake (1000-1500 mg daily) is necessary alongside vitamin D for optimal bone health 1
• Mineral oil interferes with vitamin D absorption 4
• Thiazide diuretics may cause hypercalcemia in patients taking vitamin D supplements 4

Pitfalls to Avoid

1. Overlooking severe deficiency: Severe vitamin D deficiency (<5 ng/mL) dramatically increases risk of mortality, infections, and other diseases 5

2. Excessive supplementation: High doses (>4000 IU/day) have been associated with increased falls and fractures 6

3. Inadequate monitoring: Failure to follow up with 25(OH)D measurements may lead to under or over-treatment

4. Ignoring comorbidities: Patients with kidney disease, malabsorption, or on certain medications require specialized approaches 1

5. Neglecting calcium: Vitamin D supplementation should be accompanied by adequate calcium intake for optimal bone health 1

The most recent evidence suggests that a daily dose of 2000 IU (50 μg) of vitamin D3 may be sufficient to raise and maintain serum 25(OH)D concentrations above 50 nmol/L in >99% of adults and above 75 nmol/L in >90% of adults, with no significant safety concerns 7. However, treatment should still be tailored based on the severity of deficiency as outlined above.