November 29, 2014 08:23 UTC

Science & Technology

Vitamins are Important to Good Health

Experts say there is little evidence that most vitamin supplements protect or improve health.

Mia Farrow gives a child a dose of vitamin A.
Mia Farrow gives a child a dose of vitamin A.

Multimedia

Play or download an MP3 of this story

This is SCIENCE IN THE NEWS, in VOA Special English. I’m Bob Doughty.

 
And I’m Faith Lapidus. This week, we tell about vitamins.
 
Many jobs must be done with two people. One person takes the lead. The other helps. It is this cooperation that brings success.
 
So it is with the human body. Much of our good health depends on the cooperation between substances. When they work together, chemical reactions take place smoothly. Body systems are kept in balance.
 
Some of the most important helpers in the job of good health are the substances we call vitamins.
 
The word “vitamin” dates back to Polish scientist Casimir Funk in 1912. He was studying a substance in the hull that covers rice. This substance was believed to cure a disorder called beriberi.
 
Funk believed the substance belonged to a group of chemicals known as amines. He added the Latin word "vita," meaning life. So he called the substance a “vitamine” -- an amine necessary for life.
 
Funk was not able to separate the anti-berberi substance from the rice hulls. It was later shown to be thiamine. Other studies found that not all vitamines were amines. So the name was shortened to vitamin. But Funk was correct in recognizing their importance.
 
Scientists have discovered thirteen kinds of vitamins. They are known as vitamins A, the B group, C, D, E and K. Scientists say vitamins help to carry out chemical changes within cells. If we do not get enough of the vitamins we need in our food, we are at risk of developing a number of diseases.
 
This brings us back to Casimir Funk. His studies of rice were part of a long search for foods that could cure disease.
 
One of the first people involved in that search was James Lind of Scotland. In the 1740s, Lind was a doctor for the British Navy. He was investigating a problem that had existed in the Navy for many years.
 
The problem was the disease scurvy. So many sailors had scurvy that the Navy’s fighting strength was very low. The sailors were weak from bleeding inside their bodies. Even the smallest wound would not heal. Doctor Lind thought the sailors were getting sick because they failed to eat some kinds of foods when they were at sea for many months.
 
Doctor Lind separated 12 sailors who had scurvy into two groups. He gave each group different foods to eat. One group got oranges and lemons. The other did not. The men who ate the fruit began to improve within seven days. The other men got weaker. Doctor Lind was correct. Eating citrus fruits prevents scurvy.
 
Other doctors looked for foods to cure the diseases rickets and pellagra. They did not yet understand that they were seeing the problem from the opposite direction. That is, it is better to eat vitamin-rich foods to prevent disease instead of eating them to cure a disease after it has developed.
 
Which foods should be eaten to keep us healthy? Let us look at some important vitamins for these answers.
 
Vitamin A helps prevent skin and other tissues from becoming dry. It is also needed to make a light-sensitive substance in the eyes. People who do not get enough vitamin A cannot see well in darkness. They may develop a condition that dries the eyes. This can result in infections and lead to blindness.
 
Vitamin A is found in fish liver oil. It also is in the yellow part of eggs. Sweet potatoes, carrots and other darkly colored fruits and vegetables contain substances that the body can change into vitamin A.
 
Vitamin B-one is also called thiamine. Thiamine changes starchy foods into energy. It also helps the heart and nervous system work smoothly. Without it, we would be weak and would not grow. We also might develop beriberi.
 
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.
 
Another B-vitamin is niacin. It helps cells use food energy. It also prevents pellagra -- a disease that causes weakness, reddish skin and stomach problems. Niacin is found in meat, fish and green vegetables.
 
Vitamin B-12 is needed so folic acid can do its work. Together, they help produce red blood cells. Vitamin B-12 is found naturally in foods like eggs, meat, fish and milk products. Folic acid has been shown to prevent physical problems in babies when taken by their mothers during pregnancy.
 
Vitamin B-12 is found in green leafy vegetables and other foods, like legumes and citrus fruits. In some countries, it is added to products like bread.
 
In 2003, Japanese researchers identified a substance they think is a member of the B-vitamin group. It is called pyrroloquinoline quinone, or PQQ.
 
The researchers found that PQQ is important in the reproductive and defense systems of mice. They said the substance is similarly important for people. PQQ is found in fermented soybeans and also in parsley, green tea, green peppers and kiwi fruit. Other researchers have disputed the Japanese findings. They say more information is needed to confirm them.
 
Vitamin C is needed for strong bones and teeth, and for healthy blood passages. It also helps wounds heal quickly. The body stores little vitamin C. So we must get it every day in foods such as citrus fruits, tomatoes and uncooked cabbage.
 
Vitamin D increases levels of the element calcium in the blood. Calcium is needed for nerve and muscle cells to work normally. It also is needed to build strong bones.
 
Vitamin D prevents the children’s bone disease rickets. Ultraviolet light from the sun changes a substance in the skin into vitamin D. Fish liver oil also contains vitamin D. In some countries, milk producers add vitamin D to milk so children will get enough.
 
Vitamin K is needed for healthy blood. It thickens the blood around a cut to stop bleeding. Bacteria in the intestines normally produce vitamin K. It can also be found in pork products, liver and in vegetables like cabbage, kale and spinach.
 
Experts agree that everyone needs vitamins so that their bodies can operate normally. In general, a complete diet should provide all the vitamins a body needs in their natural form. In addition, many foods and food products now have extra vitamins and minerals added.
 
Some people fear they do not get enough vitamins from the foods they eat. So they take products with large amounts of vitamins. They think these products, called vitamin supplements, will improve their health and protect against disease. Many adults now take vitamin supplements every day.
 
In 2006, medical experts gathered near Washington, D.C. to discuss studies about vitamin supplements. The experts reported finding little evidence that most supplements do anything to improve health. But they noted that some do help to prevent disease.
 
The experts said women who wish to become mothers should take folic acid to prevent problems in their babies. And, they said vitamin D supplements and calcium can protect the bones of older women.
 
The medical experts agreed with doctors who say that people who know they lack a vitamin should take vitamin supplements. Some older adults, for example, may not have enough vitamin B-twelve. That is because, as people get older, the body loses its ability to take it from foods.
 
The experts also noted that taking too much of some vitamins can be harmful. They said people should be sure to discuss what vitamins they take with their doctors.
 
Several studies have not been able to show that taking vitamin supplements in addition to a balanced diet helps to prevent disease. One study found that older Americans do not get enough Vitamin C and required minerals. The study involved more than six thousand individuals. More than half of them took vitamin supplements.
 
Vitamins are important to our health. A lack of required vitamins can lead to health problems.
 
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. Experts say this is why it is important to eat a mixture of foods every day, to get enough of the vitamins our bodies need.
 
This SCIENCE IN THE NEWS program was written by Brianna Blake. I’m Faith Lapidus.
 
And I’m Bob Doughty. Join us again next week for more news about science in Special English on the Voice of America.



 
This forum has been closed.
Comment Sorting
Comments
     
by: DADDI MOUSSA IDER Abdalla from: Frence
04/26/2013 5:52 PM
As it is written in the text, it is very important to have a mixture of food, in order to get the maximum of vitamins.
We learn from this text, each food what it contains of vitamins A, B, C, D, E and K.
Think you VOA Special English for these scientific texts which improve our English.


by: Elmer from: Chimbote, Peru
04/25/2013 3:00 PM
I always listen to My friend Clare every morning that She wants to drink tea green now, I see the reason, The vitaiments are very important to our life, I think everyone need to care their health, thank yoy for making this artcilce, apart that it teaches me to learn English, it permit to improve my health,, thank you


by: BIJU.P.Y. from: SOUTH INDIA
04/24/2013 6:50 AM
Excellent, very useful information. But the story has been told many times so that I have almost by hearted it. But a reminder is always a good idea to remember something- so important. Thank you.

Learn with The News

  • Ferguson Protest

    Video After Protests, Ferguson Looks for Answers

    On Monday, protesters burned buildings and police cars and destroyed businesses in the Midwestern U.S. city of Ferguson, Missouri. Their actions followed the announcement that a grand jury had decided not to send a white police officer to trial for shooting and killing an unarmed black teen. More

  • Video US Evangelicals Debate Homosexuality in the Bible

    An increasing number of mainline Christian groups are also accepting same-sex unions. But most evangelical Christians say the Bible condemns sexual relations among people of the same sex. Now, a well-known student of evangelicalism is saying that the traditional reading of the Bible is wrong. More

  • An oil derrick is seen at a fracking site for extracting oil outside of Williston, North Dakota March 11, 2013.  North Dakota's booming oil business has quickly ran up against a serious shortage of housing for the thousands of workers who have poured into

    Audio Falling Oil Prices Affect Nations Differently

    Oil prices have dropped 30 percent since June. Increased American oil production is one reason for the drop in world oil prices. Nigeria has announced measures the government would take to increase income. But, in India the lower oil prices have helped ease inflation. More

  • Audio North Korea Warns of Punishment for US, Allies

    North Korea said it would punish countries that supported a UN resolution condemning North Korea's human rights record. The recent U.N. committee vote called on the Security Council to send North Korea to the International Criminal Court for suspected violations, including torture and murder. More

  • A Libyan military soldier fires his weapon during clashes with Islamic extremist militias in Benghazi, Libya, Thursday, Oct. 30, 2014. Government troops entered central Benghazi Wednesday after nearly 10 days of fighting Islamic extremist militias, a mili

    Audio Unrest, Abuse Prevent Solution in Libya

    Amnesty International is condemning all sides in Libya for human rights abuses and violations of international law. The rights group is calling on militia commanders to end the abuses. But that call is unlikely to have much of an effect on the commanders, who have never been punished. More

Featured Stories

  • Hunger Games: Mockingjay

    Video 'Hunger Games' Expected to Top Holiday Ticket Sales

    'Mockingjay - Part 1' is the third in the four part movie series. It earned about $123 million in its opening weekend. Not bad, but millions less than tickets sales in the release weekend of the first two 'Hunger Games' films. What explains the drop in audience interest? More

  • Battle of Cold Harbor

    Audio Strong Defense at Cold Harbor Gives Lee His Last Major Victory

    After Northern forces defeated Southern troops at Gettysburg, Pennsylvania and Vicksburg, Mississippi, General Ulysses Grant decided to hit the Confederates with the full force of the Union armies. The fight did not go as he expected. But General Grant was resolved to defeat the Confederates. More

  • Alzheimer brain

    Audio East Meets West to Treat Alzheimer's Patients

    But researchers in California say a new way of treating Alzheimer’s disease is showing promise for reversing some of that memory loss. The new treatment combines western medicine with eastern philosophy – ideas rooted in Asian religions. More

  • Mr. Van Rijsselberghe worked on the project with scientists from the Free University of Amsterdam.

    Video Dutch Experiment Grows Vegetables in Sea Water

    Due to rising sea level, farmers are increasingly unable to use fields close to the sea. A farmer in the Netherlands is growing small, but healthy and tasty crops in a mixture of fresh and salt water. Farmers in Pakistan may soon be growing Dutch potatoes in areas affected by rising sea waters. More

  • Jonathan Evans Performs with Bonerama

    Video With Bonerama, Three Trombones Lead the Big Parade

    The New Orleans-based group brings together funk, rock, blues and jazz, creating a gumbo for the ears. Bonerama has horns like many bands. But, unlike most groups, the trombone players lead this band. Reporter Jonathan Evans performed with the band and wrote about it for American Mosaic. More

Practice Your Writing

Confessions of an English Learner BlogConfessions of an English Learner Blog

Tell us About Our Programs