From the Guidelines
The recommended daily dose of vitamin D (Cholecalciferol) for most adults is 800-1000 IU per day, with a goal of achieving a 25-hydroxyvitamin D level of at least 30 ng/mL (75 nmol/L). This recommendation is based on the most recent and highest quality study available, which suggests that vitamin D3 (cholecalciferol) is more effective in raising 25(OH)D concentrations and maintaining those levels for a longer time when longer dosing intervals are employed 1.
Key Considerations
- For patients with serum 25(OH)D levels below 30 ng/mL, a common regimen is prescription vitamin D (ergocalciferol) 50,000 IU weekly for 8 weeks, followed by a recheck of the serum 25(OH)D level, with subsequent dosing based on the results 1.
- Vitamin D toxicity (hypercalcemia, hyperphosphatemia, and activation of bone resorption) is uncommon but may occur with daily doses of more than 50,000 IU per day that produce 25(OH)D levels larger than 150 ng/mL 1.
- The NCCN Bone Health in Cancer Care Task Force recommends 800-1000 IU of vitamin D daily for adults older than age 50, and also for younger patients at risk for cancer treatment–associated bone loss 1.
Special Populations
- Elderly individuals, those with limited sun exposure, darker skin tones, or malabsorption conditions often need higher doses of vitamin D 1.
- Blood level monitoring is important, aiming for 25-hydroxyvitamin D levels between 30-50 ng/mL (75-125 nmol/L) 1.
- Vitamin D is essential for calcium absorption, bone health, immune function, and may have other health benefits, and taking it with food containing some fat improves absorption, and combining it with calcium supplementation is often beneficial for bone health 1.
From the Research
Normal Dose of Vitamin D (Cholecalciferol)
The normal dose of Vitamin D (Cholecalciferol) to prescribe can vary depending on the individual's needs and health status.
- For adults who want to ensure a sufficient vitamin D status, a dose of 800 to 2000 international units (IU) per day is recommended 2, 3.
- For the treatment of vitamin D deficiency, higher doses (e.g., 6000 IU per day) may be used for the first 4 to 12 weeks of treatment, followed by a maintenance dose of 800 to 2000 IU per day 2.
- In conditions of severe vitamin D deficiency, a maximum dose of 2,000 IU/day may be prescribed, especially with concomitant reduced or no sun exposure, reduced dietary intake, and reduced calcium absorption 3.
- A predictive equation can be used to guide vitamin D replacement dose in patients, taking into account factors such as age, body mass index (BMI), and serum albumin concentration 4.
- Daily vitamin D allowance can range from 1,500 IU (healthy adults) to 2,300 IU (elderly with low calcium intake), with a maintenance dose of 800-2,000 IU/day (or weekly equivalent) recommended for subjects recently treated for deficiency-insufficiency 5.