Vitamins are important to our health. But different vitamins are found in different foods -- grains, vegetables and fruits, fish and meat, eggs and milk products. And even foods that contain the same vitamins may have them in different amounts. Nutrition experts say this is why it is important, where possible, to eat a mixture of foods every day, to try to get enough of the vitamins our bodies need.
And this is Phoebe Zimmermann. Join us again next week for more news about science in Special English on the Voice of America.
The sailors were weak from continuous bleeding inside their bodies. Their teeth fell out. Even the smallest wound would not heal. Doctor Lind thought the sailors were getting sick because they were unable to eat some kinds of foods when they were at sea for many months.
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Vitamin C is necessary for strong bones and teeth, and for healthy blood vessels. It also helps wounds heal quickly. The body stores very little vitamin C. So we must get it every day in foods such as citrus fruits, tomatoes and uncooked cabbage.
Thiamine is found not just in whole grains like brown rice, but also in other foods. These include beans and peas, nuts, and meat and fish.
One of the first people involved in that search was James Lind of Scotland. In the seventeen-forties, Lind was a doctor for the British Navy. He was trying to solve a problem the Navy had been suffering for hundreds of years. The problem was the disease scurvy. So many British sailors had scurvy that the Navy's fighting strength was very low.
The word "vitamin" dates back to Polish scientist Casimir Funk in nineteen-twelve. He was studying a substance in the hull that covers rice. This substance was believed to cure the nervous system disorder beriberi.
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Other doctors searched for foods that would cure rickets and pellagra. They did not yet understand that they were seeing the problem backwards. That is, it is better to eat vitamin-rich foods to prevent disease instead of eating them to cure disease after it has developed.
The first vitamin discovery in the twenty-first century was made by Japanese researchers in April of two-thousand-three.
Just how do vitamins keep us healthy? Which foods are the best source for different ones? Let us look at some important vitamins for these answers.
But some people take pills each day that contain larger amounts of vitamins. They think the extra vitamins will improve their health and protect against disease. Some doctors agree. But many do not. For one thing, they point out that too much of some vitamins can be harmful to healthy people.
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For example, too much vitamin A can lead to the bone weakening condition osteoporosis. Too much vitamin B-six can damage the nervous system, causing a loss of feeling in the arms and legs. Too much vitamin E can increase the chances of developing a heart attack or stroke.
Doctor Lind was correct. Eating citrus fruits prevents scurvy.
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Funk was not able to separate the anti-berberi substance from the rice hulls; it turned out to be thiamine. And later research showed that not all vitamines were amines after all. So the name was shortened to vitamin. But Funk was correct in recognizing the importance.
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