The best title for the passage is ______.

A．People taking 200 IU got bigger immune defenses than the ones who got only 60 IU.
B．Research has found Vitamin E delays the progression of Alzheimer's disease.
C．Most of us can get sufficient Vitamin E from diet.
D．It's important to remember when taking Vitamin E: more may not be better.

A．Extremely high dose of Vitamin E can cause danger.
B．With proper dose of Vitamin E old people could be safer from infectious disease.
C．Researchers have proved that Vitamin E has no side effects.
D．Individuals with serious conditions should consult their doctors.