Vitamin C Powder, Natural

I use natural vitamin C powder (also sold as ascorbic acid) in some of my dishes to help the ingredients keep their natural colour and to help stop oxidisation. Vitamin C is made either naturally (from fruits under cold distillation) or synthetically (by machines). I prefer to use the natural one for my preparations. The only pitfall in using natural vitamin C is that when it is heated, it breaks down and any health benefits are lost.