Fun fact! Most Vitamin D prescriptions are D2...
I kid you not.
"Vitamin D2 (ergocalciferol) is the form most often prescribed because it was historically FDA-approved as a drug.
Vitamin D3 (cholecalciferol) is more commonly sold over the counter, often in capsules, tablets, or liquids." - From Chat.
Fun Fact: Since the late 1990s it was well established in the scientific literature that vitamin D3 is far superior to D2.
Yet still the FDA persists...D3 is not approved as a standard โdrugโ equivalent to D2.