SupplementScience

Types of Vitamin D3: Forms & Bioavailability

DJP
Reviewed by , MD, Board Certified Internal Medicine

This content is for informational purposes only and does not constitute medical advice. Consult your healthcare provider before starting any supplement. Full disclaimer

Forms Comparison

FormBioavailabilityBest For
Vitamin D3 (Cholecalciferol)HighGeneral supplementation — 87% more effective at raising serum levels than D2
Vitamin D2 (Ergocalciferol)ModerateVegan option — plant-derived but less potent per IU
Vitamin D3 + K2 (MK-7)HighBone health, cardiovascular protection — K2 directs calcium to bones
Liquid Vitamin D3HighFlexible dosing, those who dislike pills — easy absorption with fats
Microencapsulated D3HighSustained release, improved stability in supplements

Vitamin D3 (Cholecalciferol)

Bioavailability: High. Best for: General supplementation — 87% more effective at raising serum levels than D2.

Vitamin D2 (Ergocalciferol)

Bioavailability: Moderate. Best for: Vegan option — plant-derived but less potent per IU.

Vitamin D3 + K2 (MK-7)

Bioavailability: High. Best for: Bone health, cardiovascular protection — K2 directs calcium to bones.

Liquid Vitamin D3

Bioavailability: High. Best for: Flexible dosing, those who dislike pills — easy absorption with fats.

Microencapsulated D3

Bioavailability: High. Best for: Sustained release, improved stability in supplements.

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References

  1. (). Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data. BMJ. DOI
  2. (). Vitamin D Supplements and Prevention of Cancer and Cardiovascular Disease. New England Journal of Medicine. DOI
  3. (). Vitamin D deficiency and depression in adults: systematic review and meta-analysis. British Journal of Psychiatry. DOI
  4. (). Comparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status: a systematic review and meta-analysis. American Journal of Clinical Nutrition. DOI