Cholecalciferol versus vitamin D2 for raising vitamin D levels
What it found
In adults, cholecalciferol (vitamin D3) raised total vitamin D levels in the blood more than vitamin D2, especially in people with a healthy weight.
Both forms raised their own specific vitamin D form by similar amounts.
What they found
Studies in people
Total vitamin D levels
Across 20 comparisons, vitamin D3 raised total vitamin D levels in the blood more than vitamin D2. In 12 daily-dosed comparisons measured by a specific lab method, the vitamin D2 group ended up 10.39 nmol/L lower, which was about 40% less of a rise.
Own vitamin D forms
When researchers looked at the specific form each vitamin turns into in the body, vitamin D2 and vitamin D3 had a similar positive effect on their own forms. This was based on 9 comparisons using daily doses.
Body weight effect
Body mass index was the strongest factor affecting the difference between the two vitamins. In people with a BMI over 25, the difference between vitamin D2 and vitamin D3 disappeared, while in people with a BMI under 25, vitamin D3 clearly raised levels more.
Baseline vitamin D
In studies where most people started with vitamin D levels below 50 nmol/L, the difference between the two vitamins became non-significant. This may be because people with lower starting levels respond differently.
Dosing schedule
Daily dosing showed a smaller difference between the two vitamins than weekly dosing. However, only 3 weekly dosing studies were included, and 2 of them had a high risk of bias.
What the authors conclude
“Vitamin D3 leads to a greater increase of 25(OH)D than vitamin D2, even if limited to daily dose studies, but vitamin D2 and vitamin D3 had similar positive impacts on their corresponding 25(OH)D hydroxylated forms.”
Also in their conclusions
- They conclude that vitamin D3 leads to a greater increase in blood vitamin D than vitamin D2, even when limited to daily dose studies.
- They say that body mass index and starting vitamin D levels should be considered when comparing daily vitamin D2 and vitamin D3 supplements.
- They call for further investigation to determine whether the possible interference of BMI is partly independent from starting vitamin D levels.
How it was done
Earlier reviews found that vitamin D3 may raise blood vitamin D more than vitamin D2, but the results varied a lot between studies. The authors wanted to see whether this difference holds when only daily or weekly doses are compared, and what factors like body weight might explain the variation.
They searched for randomized controlled trials that compared vitamin D2 with vitamin D3 in healthy adults, using daily or once/twice weekly dosing. They found 17 studies with 20 comparisons, with follow-up lasting 4 to 48 weeks.
What it can’t tell you
- This review combines results from different studies, so it cannot prove that one vitamin directly causes a specific outcome in any one person.
- The authors could not access individual data from each study, so they could not analyze results person by person.
- Some studies did not report body mass index or starting vitamin D levels, so those findings are based on fewer comparisons.
Who paid
- Authors work at
- Amsterdam UMC location Vrije Universiteit Amsterdam, The Netherlands; Vrije Universiteit Amsterdam, The Netherlands; University of Surrey, United Kingdom
The paper
- Title
- 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
- Type
- Systematic review and meta-analysisThe authors follow a set, published method to find every relevant study, then combine the numbers from them into one result.
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- van den Heuvel EG, Lips P, Schoonmade LJ, Lanham-New SA, van Schoor NM (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:10.1016/j.advnut.2023.09.016Free full textPubMed 37865222DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error