Passage Summary: Vitamin C is usually recommended for health because it protects the body, but doctors are telling certain cancer patients to stay away from it.

Reasoning: Vitamin C is an antioxidant that protects cells from damage, yet doctors advise some cancer patients to avoid it even when they are suffering from health-damaging side effects.

Analysis: To resolve this paradox, we need a piece of information that explains why the 'protective' nature of Vitamin C would be undesirable for a cancer patient. If Vitamin C protects all cells from damage, it might also protect cancer cells from the treatments designed to destroy them, such as chemotherapy or radiation. Look for an answer that suggests Vitamin C's beneficial properties for healthy cells actually end up shielding the tumor from medical intervention.