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Types of Vitamin D3: Forms & Bioavailability

Evidence:Strong
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This content is for informational purposes only and does not constitute medical advice. Statements about dietary supplements have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease. Individual results may vary — 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.

Find the best Vitamin D3 for your needs
Ranked by form, bioavailability, and value
Full Vitamin D3 Guide

References

  1. Meta-analysisMartineau AR, Jolliffe DA, Hooper RL, et al. (2017). Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data. BMJ. DOI PubMed
  2. RCTManson JE, Cook NR, Lee IM, et al. (2019). Vitamin D Supplements and Prevention of Cancer and Cardiovascular Disease. New England Journal of Medicine. DOI PubMed
  3. Anglin RE, Samaan Z, Walter SD, McDonald SD (2013). Vitamin D deficiency and depression in adults: systematic review and meta-analysis. British Journal of Psychiatry. DOI PubMed
  4. Meta-analysisTripkovic L, Lambert H, Hart K, et al. (2012). 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 PubMed
  5. van den Heuvel EG, Lips P, Schoonmade LJ, Lanham-New SA, et al. (2024). Comparison of the Effect of Daily Vitamin D2 and Vitamin D3 Supplementation on Serum 25-Hydroxyvitamin D Concentration (Total 25(OH)D, 25(OH)D2, and 25(OH)D3) and Importance of Body Mass Index: A Systematic Review and Meta-Analysis.. Advances in nutrition (Bethesda, Md.). DOI PubMed
  6. Sobczak M, Pawliczak R (2024). Effect of Vitamin D3 Supplementation on Severe COVID-19: A Meta-Analysis of Randomized Clinical Trials.. Nutrients. DOI PubMed
  7. Tao X, Yang W, Zhang Q, Wang Y, et al. (2024). Effects of intermittent overload doses of oral vitamin D3 on serum 25(OH)D concentrations and the incidence rates of fractures, falls, and mortality in elderly individuals: A systematic review and meta-analysis.. Biomolecules & biomedicine. DOI PubMed
Show 5 more references
  1. Owczarek B, Ziomkiewicz A, Łukowska-Chojnacka E (2024). Has a High Dose of Vitamin D3 Impacted Health Conditions in Older Adults?-A Systematic Review and Meta-Analysis Focusing on Dose 100,000 IU.. Nutrients. DOI PubMed
  2. Meta-analysisManoj P, Derwin R, George S (2023). What is the impact of daily oral supplementation of vitamin D3 (cholecalciferol) plus calcium on the incidence of hip fracture in older people? A systematic review and meta-analysis.. International journal of older people nursing. DOI PubMed
  3. Meta-analysisKazemian E, Pourali A, Sedaghat F, Karimi M, et al. (2023). Effect of supplemental vitamin D3 on bone mineral density: a systematic review and meta-analysis.. Nutrition reviews. DOI PubMed
  4. Bislev LS, Wamberg L, Rolighed L, Grove-Laugesen D, et al. (2022). Effect of Daily Vitamin D3 Supplementation on Muscle Health: An Individual Participant Meta-analysis.. The Journal of clinical endocrinology and metabolism. DOI PubMed
  5. Sanabria A, Rojas A, Arevalo J (2019). Meta-analysis of routine calcium/vitamin D3 supplementation versus serum calcium level-based strategy to prevent postoperative hypocalcaemia after thyroidectomy.. The British journal of surgery. DOI PubMed