Vitamin Pills: Popping Too Many?
"Most people think it's fine to take as much as they want," says
Rosenbloom. "I know people who take 10,000 mg a day." However, the
upper tolerable limit is 2,000 mg a day. "People at risk for kidney
stones can increase that risk; people also can get diarrhea. Some people have complained of food
poisoning, but it turned out they had taken too much vitamin C. People just
aren't aware how potent these vitamin supplements are."
"This can be tricky because we need some, and as we get older we need
more," Rosenbloom tells WebMD. "But the risk is that we get too much,
which can actually cause calcium to leach out of your bones." Vitamin D is
found in some calcium supplements; some orange juice products are fortified
with vitamin D. If you're somebody who can't drink dairy, getting
vitamin-fortified orange juice makes sense. "But if you do drink dairy, and
then you take a supplement, it's that layering that I get concerned about,"
This is a water-soluble vitamin, which means you just pee out
the excess, says Rosenbloom. The upper tolerable limit is 100 mg day, and in
pill form it's easy to get that much. "In high doses, people have problems
with temporary nerve damage -- they lose feeling in their hands and feet,"
she tells WebMD.
Fifteen years ago, women were told to take megadoses to help
with depression and PMS,
but that's been debunked, she says.
People focus on E to prevent Alzheimer's, heart
disease, macular degeneration, cancer, "the list goes
on," says Blumberg. The upper tolerable level is 1,000 milligrams (1,500
IU); the RDA is 30 IU. "There is no way to get an overdose from diet or
fortified foods. In an Alzheimer's study, people took 2,000 IU for four years
and didn't have any adverse effects. In another study, people took 800 IU for
six years, with no adverse effects, he says.