Can You Overdose on Vitamins?
Too much of a good thing can have unexpected consequences. Just ask people who have gulped
gallons of carrot juice, which is rich in beta carotene, only to find that the palms of
their hands and the soles of their feet turned a dull yellowy orange.
The carrot-juice syndrome is generally thought to be harmless and reversible, but
overdosing on some other vitamins and minerals can have serious side effects.
Vitamin A
Gorging on this vitamin compound in doses of more than 25,000 IUs (five times the RDA) can
lead to liver damage, hair loss, blurred vision and headaches.
Bitamin B-6
Ingesting more than 400 mg a day (200 times the RDA) can cause numbness in the mouth and
hands and difficulty in walking.
Vitamin C
It was once believed to cause kidney stones, but experts now say there is no solid
evidence of dangerous side effects from vitamin C. High doses can produce stomachaches and
diarrhea.
Vitamin D
In daily doses of 50,000 IUs (125 times the U.S. RDA), the sunshine vitamin can cause the
buildup of calcium deposits that can interfere with the functioning of muscles, including
heart tissue. While sunbathing will never create an overdose, taking too many supplements
can.
Niacin
Doctors prescribe doses of 2,000 mg (100 times the RDA) to help lower cholesterol. But
patients who take that much should be monitored for possible symptoms of jaundice and
liver damage.
Iron
Those who want to bolster their red blood cell count, especially elderly people and
menstruating women, have been taking iron supplements for years. Daily doses higher than
100 mg (six times the RDA) could interfere with absorption of zinc, a mineral that speeds
wound healing and helps regulate the immune system.
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