The manufacturing procedure for sodium ascorbate involves dissolving ascorbic acid in solution with sodium bicarbonate (prepared from sea water). This process removes the bicarbonate from the sodium replacing it with ascorbic acid forming sodium ascorbate. This process produces a truly buffered vitamin C. Each teaspoon = 4,725 mg Vitamin C.
I cant find the larger study I read recently on this but basically sodium ascorbic is ascorbic acid and sodium bicarbonate!