What is the recommended treatment for vitamin D deficiency?

Treatment of Vitamin D Deficiency

The recommended treatment for vitamin D deficiency is initial correction with 50,000 IU of vitamin D weekly for 8 weeks, followed by maintenance therapy of 800-2000 IU daily once target levels are achieved. 1

Diagnosis and Classification

• Vitamin D deficiency is defined as serum 25-hydroxyvitamin D (25(OH)D) levels <20 ng/mL (50 nmol/L)
• Vitamin D insufficiency is defined as 25(OH)D levels of 20-30 ng/mL (50-75 nmol/L)
• Optimal target range is 30-40 ng/mL (75-100 nmol/L) 1

Treatment Protocol

Initial Correction Phase

• For documented vitamin D deficiency:
  • Administer 50,000 IU of ergocalciferol (vitamin D2) weekly for 8 weeks 1, 2
  • Alternative approach: Calculate loading dose using formula: Dose (IU) = 40 × (75 - current serum 25(OH)D in nmol/L) × body weight in kg 3

Maintenance Phase

• After correction of deficiency:
  • 800-2000 IU of cholecalciferol (vitamin D3) daily 1, 2
  • Alternative: 50,000 IU monthly 1

Population-Specific Dosing

Population	Recommended Daily Dose
Adults up to age 70	600-2000 IU/day
Adults over 70 years	800-2000 IU/day
Dark-skinned or veiled individuals	800 IU/day
Institutionalized individuals	800 IU/day
Patients with chronic kidney disease	Specialized approaches [1]

Monitoring and Safety

• Measure 25(OH)D levels after 3 months of supplementation to assess efficacy and adjust dosing 1
• Annual testing for patients with risk factors 1
• Safety upper limit for vitamin D levels is 100 ng/mL (250 nmol/L) 1
• Toxicity typically occurs at levels above 150 ng/mL 1

Important Safety Considerations

• Discontinue vitamin D therapy if serum corrected total calcium exceeds 10.2 mg/dL 1
• Monitor urinary calcium to detect hypercalciuria 1
• Avoid single large doses of 300,000-500,000 IU 4
• Individualize dosage and exercise caution to prevent serious toxic effects, especially in vitamin D resistant rickets where the therapeutic window is narrow 5

Dietary and Lifestyle Recommendations

• Maintain normal calcium intake (1,000-1,200 mg daily) primarily from food sources 1
• Take calcium supplements with meals to reduce oxalate absorption 1
• Limit sodium intake to reduce urinary calcium excretion 1
• Maintain high fluid intake (at least 2.5 liters of urine daily) 1
• Consider sensible sun exposure as a natural source of vitamin D 4

Risk Factors for Vitamin D Deficiency

• Malabsorption conditions (inflammatory bowel disease, celiac disease)
• Limited sun exposure
• Dietary insufficiency
• Chronic kidney disease (especially GFR <30 mL/min/1.73m²)
• Liver disease
• Nephrotic syndrome 1

Clinical Manifestations

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 2

Drug Interactions and Precautions

• Mineral oil interferes with vitamin D absorption
• Thiazide diuretics may cause hypercalcemia in hypoparathyroid patients on vitamin D therapy
• Use with caution in pregnancy (safety not established for doses >400 IU daily)
• Monitor serum calcium in nursing infants when mothers receive large doses 5