Yes. Like I said. More efficacious. That doesn't make D2 "useless at best". Both D2 and D3 have metabolites that bind to the (human) Vitamin D receptor[1]. BTW

Yes. Like I said. More efficacious. That doesn't make D2 "useless at best". Both D2 and D3 have metabolites that bind to the (human) Vitamin D receptor[1]. BTW both need to go through liver/kidney[2], D3 by itself is similarly "useless" otherwise. [1] https://en.wikipedia.org/wiki/Ergocalciferol#Mechanism https://en.wikipedia.org/wiki/Ergocalciferol#Mechanism [2] https://en.wikipedia.org/wiki/Cholecalciferol#Mechanism_of_action https://en.wikipedia.org/wiki/Cholecalciferol#Mechanism_of_a...