Vitamin D2 vs D3
This one has a clear winner
Vitamin D3 wins. It's 87% more effective at raising blood levels than D2. Choose D3 unless you're vegan and can't find vegan D3 (which now exists from lichen).
Head-to-Head Comparison
Same as D3
Key Fact: Plant-derived (fungi/yeast). Prescription D is usually D2 because it was patented first.
Rare at normal doses
Key Fact: The form your body makes from sunlight. 87% more effective at raising blood levels than D2.
Which One For Your Goal?
| Your Goal | Winner |
|---|---|
| Raising blood levels | D3 |
| Maintaining levels | D3 |
| Bone health | D3 |
| Immune function | D3 |
| Vegan option | D2 or Lichen D3 |
| Cost | Tie |
Myth vs Reality
Myth: "My doctor prescribed D2, so it must be better." Reality: Prescription D2 exists because of patent history, not efficacy. If your doctor prescribes D2, ask about switching to D3. Most will agree once you bring it up.
Why Vitamin D3 (Cholecalciferol) Wins
D3 wins decisively. It's 87% more effective at raising and maintaining vitamin D blood levels. D2 exists because it's cheaper to produce and was patented first. There's no good reason to choose D2 unless you're strictly vegan.
Common Questions
2000-5000 IU daily for most adults, especially if you don't get sun. Get blood work to dial in your dose.
The Bottom Line
Take D3. It's not even close. If you're vegan, look for vegan D3 from lichen (several brands now make it). D2 is an inferior product kept alive by pharmaceutical inertia.
More Showdowns
About this information: Our recommendations draw from peer-reviewed clinical trials, systematic reviews, and the same medical databases your doctor uses. These statements have not been evaluated by the FDA. Supplements are not intended to diagnose, treat, cure, or prevent any disease.
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