CatchR,
The recommended vitamin C is not for increasing the effectiveness of the chelating agent.
Most thalassemia patients are deficient in vitamin C - and this vitamin has some very important purposes in bodily functions. Vitamin C is strong antioxidant - and thals need antioxidant protection. There are countless other vital functions that this vitamin serves.
The team at Oakland and other thalasemia centers recommend that along with vitamin e, zinc, vitamin d and others - that thals take a small dose of vitamin C. 205mg daily has been recommended for my 40kg son.
I think that there is some confusion around this subject - as vitamin c was once recommended to be taken with desferal - and aided the process - when patients switched to oral chelators it was assumed that vitamin C is no longer required. Taking large doses of vitamin C, can dispel iron from the liver - but this is not a concern when taking small doses of vitamin C at a time. The body does not store vitamin C so it is important to continue to take vitamin C either through supplementation or vitamin C rich foods.
I hope this helps
Sharmin