A patient recently insisted on Vitamin D2 instead of D3. She told me that she always uses plant sources because they are “more natural”. Indeed Vitamin D2 (Ergocalciferol) is more natural if you are a cabbage or other plant. But all humans naturally make and use Vitamin D3 (Cholecalciferol). Why not D2? Did God make a mistake designing humans to make and use D3?
Activated Vitamin D3 is a hormone used by our bodies in well over a hundred different functions including absorption of calcium from food, nerve functioning, and our immune system. Vitamin D2 is similar enough to D3 that we can also use it. However, we need much higher doses, and the waste products of D2 build up in our bodies.
Humans naturally make their own Vit D3 when they are exposed to the mid-day sun. In the tropics this works all year round. In Iowa it only works April through September. When humans moved north of the tropics we had to supplement our Vitamin D by eating animals that store a lot of D3 in their bodies. Salmon, seal blubber, and cod livers are high in D3. This was how humans managed for hundreds of generations.
A few decades ago we discovered how to chemically extract Vitamin D2 from plants and D3 from animals. One decade ago we learned how to trick bacteria into making authentic D3 for us even more cheaply. The only thing more natural would be to move to the tropics and deal with lots of skin cancer in our 40s and 50s.
Take Control Naturally with D3, the stuff that your body makes and was designed to use.
Jay Ginther, MD