Originally Posted By: crackemI don't know about animals, but most human studies show that Ester-C shows no benefit over regular old ascorbic acid (vit. C) other than reduced gastric sensitivity.
There are other forms such as the calcium ascorbate and sodium ascorbate, which just attaches a mineral onto the vit C. and it has some decrease in GI sensitivity over regular vit. C as well.
unlike other vit's such as vit E, there is no difference really between synthetic or natural vit C. with things like Vit, E, you want natural vit. E
Here's your answer: http://bajaokla.com/dachback/ester_c.htm