Ergocalciferol and vitamin D3 compared for raising blood vitamin D levels
What it found
Most trials in people found vitamin D3 raised blood vitamin D levels more than ergocalciferol.
A few trials found no difference between the two forms.
What they found
Studies in people
Raising blood vitamin D
Most intervention trials in people showed vitamin D3 raised blood vitamin D levels more than ergocalciferol. Four trials found them equally effective. No trial found ergocalciferol worked better.
Large single doses
When researchers combined data from seven trials giving large single doses, vitamin D3 raised blood levels more than ergocalciferol. When they looked only at daily doses, the difference between the two was smaller and not clear.
Effect on each other
In several trials in people, taking ergocalciferol lowered existing vitamin D3 levels in the blood. Taking vitamin D3 did not lower ergocalciferol levels.
Adding to foods
Foods like breakfast cereals and non-dairy milks can have either form added. Fortified foods currently add very little to what UK adults take in each day. Bread baked with UV-treated yeast did not raise blood vitamin D levels in one trial in people.
Other findings
How they are made
Ergocalciferol is made when plant compounds are exposed to UVB light. Vitamin D3 is made in human and animal skin by sunlight, or commercially from sheep wool fat using UVB light.
Suitability for vegans
Ergocalciferol comes from plants and fungi. Vitamin D3 usually comes from animals, so it is not suitable for vegans.
What the authors conclude
- They say most trials show vitamin D3 raises blood vitamin D levels better than ergocalciferol, but study designs were often too small to be certain.
- They call for a large, strong trial to give clear answers about which form works best.
- They advise that cost, availability and vegan suitability must be considered when choosing which form to add to foods.
How it was done
Vitamin D deficiency is a global issue, and natural sources from food and sunlight are limited. The UK set new dietary targets, so clearer evidence was needed on whether adding ergocalciferol or vitamin D3 to foods works better.
The authors gathered results from multiple trials comparing ergocalciferol and vitamin D3 in people. They looked at how well each form raised total 25-hydroxyvitamin D levels in the blood. Trial sizes ranged from 19 to 107 participants, lasting from 14 days to 12 months.
What it can’t tell you
- Many of the trials had too few people to give firm answers.
- Scientists do not yet know if low blood vitamin D causes disease or is just a sign of it.
- Results from short trials cannot show what happens over many years.
Who paid
- Funding
- Funded by Biotechnology and Biological Sciences Research Council; Department of Health (from the PubMed record).
- Authors work at
- University of Surrey, UK
The paper
- Title
- Vitamin D deficiency as a public health issue: using vitamin D2 or vitamin D3 in future fortification strategies
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Wilson LR, Tripkovic L, Hart KH, Lanham-New SA (2017). Vitamin D deficiency as a public health issue: using vitamin D2 or vitamin D3 in future fortification strategies. The Proceedings of the Nutrition Society. doi:10.1017/S0029665117000349Free full textPubMed 28347378DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error