Being cajoled by your parents to eat your vegetables is a common childhood memory, and most people know that getting an adequate intake of vitamins is required for good health. What your parents didn't tell you, though, was that eating too much of some vitamins could make your skin peel off, your fingers go tingly or your skin turn yellow.
In 1999, a little girl who loved drinking a particular orange-flavored drink began to turn yellow. Her parents brought her to the hospital, where a doctor was surprised to find that the child didn't have a serious disease but instead had ingested too much beta carotene from her favorite drink. Beta carotene turns into vitamin A in the body. The girl was diagnosed with a condition called carotenemia. As you might guess from the name, carotenemia can also occur if you eat lots of carrots, and it can occur if you eat certain other yellow or red vegetables too. People with carotenemia turn back to their usual color once they change their diet.
Polar Bear Liver
Beta carotene comes from plants, but vitamin A itself can also be obtained from eating meat, especially liver. Some of the most interesting cases of vitamin A overdose involve explorers in the Arctic eating polar bear liver. Some explorers ate small amounts of liver without any problems, according to a 1942 article in "Biochemical Journal," but others were not so lucky. First came stupor and headache, and then their skin actually peeled off. The indigenous people of the Arctic already knew not to eat polar bear liver, but unfortunately it took longer for the visiting explorers to figure this out the hard way.
Scurvy used to be a disease affecting sailors on long voyages who became deficient in vitamin C: Their teeth became loose, their breath became stinky and they bled easily. Although Native Americans knew of a cure for the condition in the 16th century, using pine needle tea, it took until the late 18th century for the British Royal Navy to implement another effective cure, juice from citrus fruits, to protect their sailors. Specifically, the British sailors drank lime juice, earning them the nickname Limeys, which is still in use today.
One strange result of a vitamin deficiency is an odd numbness or tingling in your fingers or toes. This is due to a deficiency of B12, which helps keep the nerves healthy. Some people eat diets that do not contain meat, fish or eggs and so are at risk of vitamin B12 deficiency. The tingly sensation can be reversed with B12 supplementation. In severe deficiency, though, some people actually "forget" where their limbs are because the normal sensation of position is damaged. This makes affected people wobbly when walking.