What is the typical treatment dose for vitamin D (Vitamin D) deficiency?

Normal Dosing for Vitamin D Deficiency

For vitamin D deficiency (<20 ng/mL), the recommended treatment is oral ergocalciferol (vitamin D2) 50,000 IU once weekly for 8-12 weeks, followed by maintenance therapy of 800-2000 IU daily. 1, 2

Treatment Based on Deficiency Severity

• For vitamin D insufficiency (20-30 ng/mL), adding 1000 IU vitamin D daily to current intake and rechecking levels in 3 months is recommended 1
• For vitamin D deficiency (<20 ng/mL), start with a loading dose of 50,000 IU vitamin D2 once weekly for 8 weeks 2
• For severe deficiency (<10-12 ng/mL), 50,000 IU weekly for 12 weeks followed by monthly maintenance is recommended, especially with symptoms or high fracture risk 1, 2
• Each 1,000 IU of vitamin D supplementation typically increases serum 25(OH)D levels by approximately 10 ng/mL, though individual responses vary significantly 2

Maintenance Phase

• After completing the loading dose regimen, transition to a maintenance dose of 800-2000 IU daily 2
• Vitamin D3 (cholecalciferol) is preferred over vitamin D2 (ergocalciferol) for maintenance therapy, especially when using intermittent dosing regimens 2
• For convenience, a monthly dose of 50,000 IU can achieve the equivalent of approximately 1,600 IU daily 1
• For patients who prefer less frequent dosing, 50,000 IU monthly or 100,000 IU every 3 months are effective maintenance options 2

Special Populations

• For patients with malabsorption or obesity, higher maintenance doses may be required (2000-4000 IU daily) 2, 3
• For elderly patients (≥65 years), institutionalized individuals, and those with dark skin or limited sun exposure, supplementation with 800 IU/day can be initiated without baseline testing 2
• For patients with chronic kidney disease, vitamin D supplementation is particularly important as kidney disease increases deficiency risk 1, 2
• For obese patients or those with liver disease or malabsorption syndromes, higher doses of 7000 IU/day or 30,000 IU/week may be needed as maintenance therapy 3

Monitoring Response to Treatment

• Measure 25(OH)D levels after at least 3-6 months of supplementation to allow serum levels to reach plateau 1, 2
• Target 25(OH)D level should be at least 30 ng/mL (75 nmol/L) for optimal health benefits 2, 4
• The upper safety limit for 25(OH)D is considered to be 100 ng/mL (250 nmol/L) 2

Important Considerations

• Single very large doses (>300,000 IU) should be avoided as they may be inefficient or potentially harmful 1, 5
• Vitamin D supplementation benefits are primarily seen in those with documented deficiency, not in the general population with normal levels 1, 2
• Calcium intake should be assessed alongside vitamin D supplementation, with recommended daily intake of 1000-1500 mg 1, 2
• Vitamin D toxicity is rare but can occur with prolonged high doses (typically >10,000 IU daily) 1, 2
• Daily doses up to 4000 IU are generally considered safe for adults 1

Factors Affecting Vitamin D Response

• Significant factors affecting the change in serum concentrations of 25-hydroxyvitamin D include starting serum concentration, body mass index (BMI), age, and serum albumin concentration 6
• The recommended daily allowance for vitamin D is often inadequate for correcting low serum concentrations of 25-hydroxyvitamin D in many adult patients 6
• About 5000 IU vitamin D3/day is usually needed to correct deficiency in some patients, and the maintenance dose should be ≥2000 IU/day 6