L Ascorbic Acid Crystals is Real Vitamin C and is pure Acid, and along with Baking Soda as a buffer.
Calcium Ascorbate is used in the injectable form, but is hard to digest, and not as much Ascorbic Acid is absorbed in the system.
It's called powder as that is what it looks like, but it's Crystals, and the pure Acid only come's in a crystal form.