Wayne Boatwright wrote:
>
> Generally, excesses of fat soluble vitamins can be toxic. Escesses of
> water soluble vitamins are flushed out through the urine.

As Om mentioned, you can't get vitamin A poisoning
from beta-carotene. The excess is stored in fatty
tissues, and high levels can give you an orange
color. A friend of mine has a sister who has that,
because she tons of carrots.

The free-radical theory of cancer predicts that
antioxidants like beta-carotene will be useful
for cancer prevention because they quench the
free radicals before they can damage DNA. However,
once the cancer is started, antioxidants are not
likely to be helpful because free radicals are
not needed for the growth and spread of the cancer.

If she's on chemotherapy or radiation, she should
not be eating any root vegetables because of her
lowered immunity. A friend of mine is currently
on both, and she has a long list of foods to avoid.