Vitamin D supplements are available in two primary forms: Vitamin D3 (cholecalciferol) and Vitamin D2 (ergocalciferol). While both forms are commonly used in dietary supplements, they differ in their source materials, manufacturing processes, and product applications.
This guide provides a general overview of Vitamin D3 and Vitamin D2, helping consumers better understand the terminology commonly found on supplement labels.
If you've shopped for a vitamin D supplement, you've likely noticed two forms on labels: Vitamin D3 (cholecalciferol) and Vitamin D2 (ergocalciferol).
What is Vitamin D3?
Traditional Vitamin D3 is often sourced from lanolin (sheep's wool). Vegan Vitamin D3 sourced from lichen is now widely available and offers an alternative option for consumers seeking plant-based supplement products.
When comparing vitamin D supplements, consumers may wish to review ingredient sourcing, certifications, and product specifications to find an option that aligns with their preferences.
What is Vitamin D2?
Vitamin D2, also known as ergocalciferol, is another form of vitamin D used in dietary supplements and fortified foods. It is commonly derived from yeast or other plant-based sources and is often selected for vegetarian or vegan supplement formulations.
Like Vitamin D3, Vitamin D2 is available in multiple supplement formats and can be found in both retail and professional product lines.
D3 vs D2: What the Research Shows
Comparing Vitamin D3 and Vitamin D2
When reviewing vitamin D supplements, consumers may notice differences in:
- Source materials
- Supplement formats
- Capsule, tablet, softgel, or liquid delivery systems
- Vegan versus non-vegan formulations
- Ingredient sourcing
- Delivery formats
- Serving formats
- Manufacturer certifications
- Manufacturing standards
- Third-party testing programs
Because supplement formulations vary by manufacturer, reviewing product labels, ingredient information, and quality certifications can help consumers compare available options.
What About Vegan Vitamin D3?
Traditional D3 is derived from lanolin (sheep's wool), making it unsuitable for vegans. However, vegan D3 sourced from lichen (Cladonia rangiferina) is now widely available and provides the same cholecalciferol form as animal-derived D3 — making it the best choice for plant-based individuals.
Popular Vitamin D Products Available
Life Extension
Pure Encapsulations
Metagenics
NOW Foods
Douglas Laboratories
Consumers can compare delivery formats, serving sizes, ingredient preferences, and brand certifications when selecting a vitamin D supplement.
The Bottom Line
Vitamin D3 and Vitamin D2 are two commonly available forms of vitamin D used in dietary supplements. Understanding the differences between their sources, formulations, and product formats can help consumers better understand supplement labels and product information.
When reviewing vitamin D products, consumers may wish to compare ingredient transparency, manufacturing standards, third-party testing, and preferred delivery formats.