Comparison Article
Vitamin D3 (Cholecalciferol)
vs Vitamin D2 (Ergocalciferol)
Vitamin D supplementation is crucial for bone health, immune function, and overall wellbeing. But the choice between D3 and D2 forms matters more than many realize. Our data analysis reveals significant differences in effectiveness and value.
Data & Scoring Methodology
Our scores are calculated based on three core pillars: Value (cost per active gram), Potency (concentration per serving), and Convenience (servings per size). This article analyzes specific products that share identical serving sizes to ensure a scientifically fair comparison. While higher scores generally indicate better efficiency, individual results depend on your specific health goals and ingredient sensitivities explained in the analysis below.
Quick Verdict
Vitamin D3 is the clear winner for most people due to its superior bioavailability and effectiveness. The only reason to choose D2 is for vegan/vegetarian dietary requirements, and even then, higher doses may be needed to achieve the same results.
Updated February 2026
Understanding the Options
Vitamin D3 (Cholecalciferol)
Vitamin D3 (cholecalciferol) is the form naturally produced in human skin when exposed to sunlight. It's derived from animal sources like lanolin (sheep wool) or fish oil. Research shows D3 is more effective at raising and maintaining blood vitamin D levels.
Vitamin D2 (Ergocalciferol)
Vitamin D2 (ergocalciferol) is derived from plant sources and fungi exposed to UV light. It was the first form used in supplements and is still common in fortified foods. D2 is the preferred choice for vegans and vegetarians.
Key Differences
The critical difference is bioavailability. D3 is approximately 87% more effective at raising vitamin D levels than D2. D3 also maintains blood levels longer. However, D2 is the only vegan-friendly option for those avoiding animal products.
Pros / Cons
Vitamin D3 (Cholecalciferol)
Pros
- 87% more effective than D2
- Better at raising blood levels
- Maintains levels longer
- More research support
- Closer to natural form
Cons
- Derived from animal sources
- Not suitable for strict vegans
- Slightly more expensive typically
Vitamin D2 (Ergocalciferol)
Pros
- Vegan-friendly
- Plant-derived
- Widely available
- Lower cost in some cases
Cons
- Less effective at raising D levels
- Shorter half-life in body
- May require higher doses
- Less research overall