Vitamin D2 (ergocalciferol) and Vitamin D3 (cholecalciferol) are both forms of vitamin D but differ in their sources and effectiveness.

Vitamin D2

Derived from plant sources like fungi or yeast that is exposed to UV light (Sun). It is commonly used in fortified foods and supplements. However, it is less effective at raising blood levels of vitamin D compared to D3.

Vitamin D3

Produced in human skin when exposed to sunlight and also found in animal-based foods like fatty fish, egg yolks, and liver. It is more bioavailable and effective at increasing and maintaining vitamin D levels in the body.

Key Difference

D3 is superior for sustaining long-term vitamin D levels, while D2 is often preferred by vegans due to its plant-based origin but may require higher doses to achieve similar effects.

Vitamin D: Comparing D2, D3 Guide to Supplements, Food Sources & Health Outcomes

Vitamin D2

Vitamin D3

Vitamin D1