Vitamin D Supplementation for Deficiency in Adults and Children

Treatment Based on Deficiency Severity in Adults

For vitamin D deficiency, the recommended dosing is 50,000 IU of cholecalciferol weekly for 8-12 weeks followed by maintenance therapy of 800-2,000 IU daily depending on severity and patient characteristics. 1, 2
For severe deficiency (<10-12 ng/mL), treatment with 50,000 IU cholecalciferol weekly for 12 weeks, followed by monthly maintenance is recommended. 1, 2
For vitamin D insufficiency (20-30 ng/mL), treatment with 4,000 IU cholecalciferol daily for 12 weeks or 50,000 IU every other week for 12 weeks is recommended. 3

After achieving target levels (≥30 ng/mL), maintenance therapy with 800-2,000 IU daily or 50,000 IU monthly is recommended. 1, 3
For elderly patients (≥65 years), a minimum of 800 IU daily is recommended even without baseline measurement. 2

For children with severe vitamin D deficiency (<5 ng/mL), treatment with 8,000 IU daily for 4 weeks, then 4,000 IU daily for 2 months is recommended. 4, 5
For children with mild deficiency (5-15 ng/mL), treatment with 4,000 IU daily for 12 weeks is recommended. 4, 5
For children with vitamin D insufficiency (16-30 ng/mL), treatment with 2,000 IU daily is recommended. 4, 5
For infants <12 months, smaller doses are recommended with an upper limit of 1,000 IU/day. 4
After repletion in children, maintenance with 200-1,000 IU daily is recommended. 4

Cholecalciferol (vitamin D3) is preferred over ergocalciferol (vitamin D2) due to higher bioefficacy. 1, 3
For convenience, monthly dosing of 50,000 IU achieves the equivalent of approximately 1,600 IU daily. 1
Adequate calcium intake (1,000-1,500 mg daily) alongside vitamin D supplementation is recommended. 1, 3

Vitamin D levels should be rechecked after 3-6 months of supplementation to ensure adequate response. 1, 3
Target serum 25(OH)D level should be at least 30 ng/mL for optimal bone health and anti-fracture efficacy. 1, 3
Development of hypercalcemia would be evidence of excessive dosing. 4

For patients with chronic kidney disease, vitamin D supplementation is particularly important as kidney disease is a major risk factor for deficiency. 1, 3
For patients requiring enteral nutrition, at least 1,000 IU per day should be provided in 1,500 kcal. 1
For patients requiring parenteral nutrition, at least 200 IU per day should be provided. 1

Daily doses up to 4,000 IU are generally considered safe for adults. 3
Vitamin D toxicity is rare but can occur with prolonged high doses (typically >10,000 IU daily). 1, 3
Single very large doses (>300,000 IU) should be avoided as they may be inefficient or potentially harmful. 1
Calcitriol, alfacalcidol, or other synthetic active vitamin D analogs should not be used to treat 25(OH)D deficiency. 4

Not ensuring adequate calcium intake alongside vitamin D supplementation. 2
Using single annual high doses which may lead to adverse outcomes. 2
Not accounting for individual variability in response to supplementation due to genetic factors, body composition, and environmental influences. 1, 3