What is the recommended treatment for vitamin D deficiency?

Treatment of Vitamin D Deficiency

The recommended treatment for vitamin D deficiency is an initial repletion phase with 50,000 IU of ergocalciferol (vitamin D2) or cholecalciferol (vitamin D3) weekly for 8 weeks, followed by maintenance therapy of 1,000-2,000 IU daily or 50,000 IU monthly to maintain 25-hydroxyvitamin D levels above 30 ng/mL. 1

Diagnosis and Target Levels

• Vitamin D deficiency is defined as serum 25-hydroxyvitamin D level <20 ng/mL (50 nmol/L)
• Vitamin D insufficiency is defined as levels between 20-30 ng/mL (50-75 nmol/L)
• The target level for optimal health is >30 ng/mL (75 nmol/L) 2, 1

Treatment Protocol

Initial Repletion Phase

• For documented vitamin D deficiency:
  • Ergocalciferol (vitamin D2) or cholecalciferol (vitamin D3) 50,000 IU weekly for 8 weeks 1, 3
  • A cumulative dose of at least 600,000 IU administered over several weeks appears necessary to replenish vitamin D stores 4
  • Avoid single large doses of 300,000-500,000 IU as they have not shown benefit and may lead to toxicity 1

Maintenance Therapy

After the initial repletion phase:

• Cholecalciferol 1,000-2,000 IU daily OR
• Ergocalciferol 50,000 IU monthly 1, 3

Special Populations

Preventive Supplementation Without Baseline Testing

The following groups may receive 800 IU/day without baseline testing 2, 1:

• Dark-skinned or veiled individuals with limited sun exposure
• Elderly individuals (≥65 years)
• Institutionalized individuals

Age-Specific Recommendations

• Adults up to age 70: 600 IU daily
• Adults over 70 years: 800 IU daily 1
• Safe upper limit for most adults: 4,000 IU daily 1, 5

Chronic Kidney Disease Patients

• For GFR >30 mL/min/1.73m²: Follow general population recommendations (800-1,000 IU daily)
• For GFR <30 mL/min/1.73m²: Either supplementing or not supplementing at doses up to ~4,000 IU daily based on clinical judgment 1

Monitoring

• Measure serum calcium, phosphorus, and 25-hydroxyvitamin D levels after at least 3 months of supplementation 2, 1
• For patients with CKD: Monthly monitoring of calcium and phosphorus for the first 3 months, then every 3 months thereafter 1
• Discontinue vitamin D therapy if serum calcium exceeds 10.2 mg/dL or serum phosphorus exceeds 4.6 mg/dL 1

Clinical Manifestations of Deficiency

Common symptoms of vitamin D deficiency include:

• Symmetric low back pain
• Proximal muscle weakness
• Muscle aches
• Throbbing bone pain elicited with pressure over the sternum or tibia 3

Safety Considerations

• The expert panel agreed on an upper safety limit for 25(OH)D of 100 ng/mL 2
• Vitamin D toxicity typically occurs at levels above 150 ng/mL 1
• Signs of toxicity include hypercalcemia, hypercalciuria, and nephrocalcinosis 1
• High-risk conditions for vitamin D supplementation include pre-existing CKD (especially stages 4-5), concurrent use of calcium supplements, rapidly worsening kidney function, poor medication compliance, and concomitant use of citrate salts with aluminum-containing medications 1

Dietary Sources

While supplementation is often necessary, dietary sources of vitamin D include:

• Fatty fish
• Cod liver oil
• Dairy products
• Fortified beverages and foods 2

The evidence strongly supports that appropriate vitamin D supplementation improves musculoskeletal health and reduces the risk of fractures and falls, particularly in older adults 1, 3. While the USPSTF does not recommend population-wide screening for vitamin D deficiency 2, appropriate treatment should be initiated once deficiency is identified.