From the Guidelines
The recommended vitamin D supplementation for most adults is 600-800 IU (15-20 mcg) daily, with higher doses of 1,000-2,000 IU daily often suggested for those with deficiency or at high risk. This recommendation is based on the most recent and highest quality study available, which suggests that daily dietary vitamin D intake of 600 IU in adults aged 18 to 70 years and 800 IU in adults older than 70 years should be sufficient to meet the needs of 97.5% of the adult population 1.
Key Considerations
- For severe deficiency (levels <20 ng/mL), healthcare providers may prescribe 50,000 IU of vitamin D2 or D3 weekly for 8-12 weeks, followed by maintenance therapy of 1,500-2,000 IU daily.
- Common supplement forms include cholecalciferol (vitamin D3) and ergocalciferol (vitamin D2), with D3 generally considered more effective at raising blood levels 1.
- Vitamin D is best absorbed when taken with meals containing fat.
- Supplementation is particularly important for individuals with limited sun exposure, darker skin tones, older adults, those with malabsorption conditions, and people living in northern latitudes.
- Vitamin D is crucial for calcium absorption, bone health, immune function, and may have roles in mood regulation and cardiovascular health.
- Blood level monitoring is recommended to ensure optimal dosing and avoid toxicity, with a target range of 30-50 ng/mL for most adults.
Additional Guidance
- The use of the terms “daily” and “per day” in these recommendations may give the false impression that a day without sunshine requires a dose of supplement 1.
- 25(OH)D3 has a half-life of 2 weeks to 3 months, and is stored primarily in adipose tissue and, to a lesser extent, in the liver.
- Summer sun exposure may provide enough for the winter, and major institutions have used dosing schedules as infrequent as once every 1–4 months 1.
From the FDA Drug Label
DIRECTIONS: Take 0ne (1) capsule each week, or as directed by your physician. Take with food. The recommended vitamin D PO supplementation is one capsule (50,000 IU) per week, or as directed by a physician 2.
- Key points:
- Take with food
- Store in a cool, dry place, protected from light
- Follow physician directions for individualized dosage instructions.
From the Research
Recommended Vitamin D PO Supplementation
The recommended vitamin D PO supplementation varies based on several factors, including age, health status, and geographic location.
- A daily dose of 2000 IU (50 µg) of vitamin D3 is suggested for adults in the general population to prevent and treat vitamin D deficiency 3.
- This dose may improve some health outcomes and is sufficient to raise and maintain serum 25(OH)D concentrations above 50 nmol/L (20 ng/mL) and above 75 nmol/L (30 ng/mL) in >99% and >90% of the general adult population, respectively 3.
- A study comparing different doses of vitamin D3 supplementation found that 2000 IU/day maintained vitamin D levels within the recommended range, even after a 30-day break, in healthy young adults 4.
- However, 4000 IU/day was more effective for maintaining levels above 100 nmol/l, supporting broader health benefits 4.
- Cholecalciferol (D3) is considered superior to ergocalciferol (D2) in treating nutritional vitamin D deficiency in chronic kidney disease (CKD) 5, 6.
- Long-term supplementation with vitamin D3 in doses ranging from 5000 to 50,000 IUs/day appears to be safe, with no cases of vitamin D3-induced hypercalcemia or adverse events attributable to vitamin D3 supplementation reported 7.
Key Considerations
- Regular monitoring of 25(OH)D, calcium, and phosphorus levels is essential when supplementing with vitamin D 4.
- The optimal method of 25-hydroxyvitamin D (25(OH)D) repletion in CKD patients is unknown, and maintenance therapy may be necessary to sustain levels 6.
- Factors such as baseline 25(OH)D level, sex, and age may influence the response to cholecalciferol supplementation 5.