Source
Vitamin D3 (Cholecalciferol)Lanolin (sheep wool), Lichen (vegan)
Vitamin D2 (Ergocalciferol)UV-irradiated yeast and mushrooms
Side-by-side analysis
Vitamin D3 vs Vitamin D2
Vitamin D3 (cholecalciferol) and Vitamin D2 (ergocalciferol) are the two primary forms of Vitamin D. However, their biological source and absorption longevity differ substantially.
Detailed Comparison
| Feature | Vitamin D3 (Cholecalciferol) | Vitamin D2 (Ergocalciferol) |
|---|---|---|
| Source | Lanolin (sheep wool), Lichen (vegan) | UV-irradiated yeast and mushrooms |
| Serum Retention | Long-lasting (weeks) | Short-lived (days) |
| Biological Potency | Superior (High affinity to binding proteins) | Inferior |
| Preferred By MDs | Yes (Preferred in clinical guidelines) | Rarely (Only prescribed in legacy high-dose D2 packets) |
Serum Retention
Vitamin D3 (Cholecalciferol)Long-lasting (weeks)
Vitamin D2 (Ergocalciferol)Short-lived (days)
Biological Potency
Vitamin D3 (Cholecalciferol)Superior (High affinity to binding proteins)
Vitamin D2 (Ergocalciferol)Inferior
Preferred By MDs
Vitamin D3 (Cholecalciferol)Yes (Preferred in clinical guidelines)
Vitamin D2 (Ergocalciferol)Rarely (Only prescribed in legacy high-dose D2 packets)
Key Benefits
Vitamin D3
- +Vitamin D3 binds tightly to vitamin D receptors and transport proteins in human blood.
- +Vitamin D2 is cleared by the liver and kidneys much faster, requiring more frequent dosing.
Our Recommendation
Always choose Vitamin D3. It is the natural hormone form synthesized by the body and is clinically proven to keep systemic vitamin D levels elevated much longer than D2.