Vitamin D Dosage Calculator
Calculate your personalized vitamin D supplementation needs based on your current blood levels.
Medical Disclaimer: This calculator provides educational estimates only and is not medical advice. Always consult your healthcare provider before starting or changing any supplement regimen. Individual needs vary based on genetics, diet, sun exposure, and health conditions.
Enter Your Information
Enter your information to calculate your personalized vitamin D dosage recommendation.
Understanding Vitamin D Levels
Optimal Blood Levels
How This Calculator Works
This calculator uses the research-based estimation that approximately 100 IU of vitamin D3 supplementation raises blood levels by 1 ng/mL.
The calculation is adjusted for body weight, as heavier individuals may require slightly higher doses to achieve the same blood level increases.
Research basis: Heaney RP, et al. "Human serum 25-hydroxycholecalciferol response to extended oral dosing with cholecalciferol." J Steroid Biochem Mol Biol. 2003.
Important Safety Information
- • The tolerable upper intake level (UL) is 4,000 IU/day for adults (per NIH)
- • Doses above 4,000 IU should be monitored by a healthcare provider
- • Toxicity is rare but can occur with prolonged intake above 10,000 IU/day
- • Vitamin D3 (cholecalciferol) is more effective than D2 (ergocalciferol)
- • Take with a meal containing fat for optimal absorption
- • Certain medications and health conditions affect vitamin D metabolism