Treatment for Severe Vitamin D Deficiency (12 ng/mL)
For a vitamin D level of 12 ng/mL, I recommend an initial loading dose of 50,000 IU of vitamin D weekly for 8 weeks, followed by a maintenance dose of 1,000-2,000 IU daily to achieve and maintain optimal levels. 1
Initial Loading Phase
A vitamin D level of 12 ng/mL indicates severe vitamin D deficiency, which requires aggressive correction. This level falls below the critical threshold of 20 ng/mL and is associated with increased risk of osteomalacia and nutritional rickets 1.
The recommended loading regimen:
- 50,000 IU of vitamin D (preferably D3/cholecalciferol) once weekly for 8 weeks 1
- This approach rapidly corrects the deficiency and has been shown to be safe and effective
Maintenance Phase
After the 8-week loading phase:
- Start maintenance therapy with 1,000-2,000 IU of vitamin D3 daily 1, 2
- Higher maintenance doses (up to 4,000-5,000 IU daily) may be required for certain populations:
Monitoring
- Recheck vitamin D level 3-6 months after starting the maintenance regimen 1
- Target level should be at least 30 ng/mL for optimal health outcomes 1
- Further dose adjustments may be necessary based on follow-up levels
Important Considerations
- Vitamin D3 (cholecalciferol) is preferred over vitamin D2 (ergocalciferol) when available, as it maintains serum levels for longer periods 1
- The rule of thumb is that each 1,000 IU of vitamin D supplementation increases serum levels by approximately 10 ng/mL, though individual responses vary 1, 4
- Vitamin D toxicity is rare and generally only occurs with daily intakes exceeding 10,000 IU for prolonged periods or when 25(OH)D levels exceed 100 ng/mL 1
Cautions
- Avoid single ultra-high loading doses (such as 500,000 IU at once), as these may be associated with adverse outcomes 1
- Patients with certain conditions (kidney disease, sarcoidosis) may require specialized dosing and more careful monitoring
- Calcium supplementation may be necessary depending on dietary intake, but should be individualized
This treatment approach balances the need for rapid correction of severe deficiency with long-term maintenance to optimize bone health and reduce risks associated with vitamin D deficiency.