Okay, to understand what Vitamin D does, we need to understand the central concept. The function of Vitamin D is to maintain blood calcium. You probably think the function of Vitamin D is to maintain strong bones and teeth. But it does that by accident. Its real function is to maintain your blood calcium level. And the reason for that is if your blood calcium level falls below about 9 milligrams per 100 milliliters, then you're longing to be in a big trouble, and die rather quickly. And that's because blood calcium is important for muscle contraction and nerve transmission. And if you don't have enough of it, you can't contract muscles normally. There can't be normal nerve impulses. And this results in a disease called tetany, where you got these uncontrolled convulsions followed by rapid death. Calcium is also important for enzymic activities and blood clotting.
The function of Vitamin D is to maintain blood calcium in a very narrow range, which is vital for human because blood calcium is important for muscle contraction and nerve transmission. If a person does not have enough calcium, he cannot contract muscles normally and it will result in uncontrolled convulsions followed by rapid death. Additionally, it also comprises that calcium is also important for enzymic activities and blood clotting.
