November 23, 2014 12:05 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

  • Brazil Religion in Latin America

    Audio Latin America Catholics Converting to Protestants

    Almost 40 percent of the world’s Catholic population, or about 425 million people, lives in Latin America. But a recent study from the Pew Research Center says people in Latin America have increasingly lost faith in the Catholic Church. Membership has decreased as much as 20 percent. More

  • This undated handout image provided by Science and the University of Tokyo shows infectious particles of the avian H7N9 virus emerging from a cell.

    Audio What's the Matter?

    From the very big to the very small, everything in our universe is made up of matter. Matter is one of those very hardworking words that you need to master ... no matter what. We will get you to the hear of the matter with this Words and Their Stories. More

  • Cambodia's Prime Minister Hun Sen (L) stretches to shake hands with China's President Xi Jinping before a meeting at the Great Hall of the People in Beijing, November 7, 2014. REUTERS/Jason Lee/POOL

    Audio Cambodian Opposition Criticize Dependence on Chinese Aid

    China’s government recently promised more than $500 million in aid to Cambodia. Cambodian officials say they need about $1 billion in foreign aid each year to operate the government. Opposition members are worried about the country becoming too dependent on aid money from China. More

  • Obama Immigration

    Video Republicans Promise to Fight Obama on Immigration

    Republican Party lawmakers are promising to fight President Barack Obama’s executive order on immigration. The order protects millions of people who have been living in the United States illegally. The president’s announcement immediately angered Republicans in the U.S. Congress. More

  • A worker at state-owned Pertamina, the country's main retailer of subsidised fuel, fills a vehicle at a petrol station in Jakarta November 17, 2014. Indonesia's president raised the price of subsidised gasoline and diesel by more than 30 percent on Monday

    Audio Indonesians Protest Rising Fuel Prices

    Indonesian President Joko Widodo announced the government would cut the financial support on fuel. The move led to a 30 percent increase in fuel overnight. These rising prices have led some public transportation groups to go on strike. The government has had to prepare other forms of transportation. More

Featured Stories

  • 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

  • A line from Abraham Lincoln's Gettysburg Address is displayed at the Lincoln Memorial in Washington, DC.

    Audio Lincoln's Words at Gettysburg Still Have Meaning

    On November 19, 1863, President Abraham Lincoln said no one would remember his speech at a battlefield cemetery in Gettysburg, Pennsylvania. But Lincoln’s Gettysburg Address remains one of the most important speeches in U.S. history. More

  • PLASTIC DREAMS

    Audio Surgery Safaris: Looking for the Perfect Body

    Many people these days are going as far as South Africa to get their version of perfection. People from across Africa and the world come for so-called “surgery safaris.” There are no animals to see on these safaris. The visitors instead look for smaller stomachs, firmer bottoms or perhaps new eye. More

  • Video South Korea Attempting to Reuse More E-Waste

    South Korea is dealing with increasing amounts of waste from electronic devices. These useless or unwanted parts are often called “e-waste.” . The city of Seoul throws out about 10 tons of e-waste each year. Some local governments in South Korea are creating special "e-waste" recycling programs. More

  • FILE - Brittany Maynard, shown with her Great Dane puppy, Charlie, took a lethal dose of medication prescribed by a doctor in Oregon on Saturday. Maynard was battling brain cancer.

    Video Should You Have the Right to Die?

    The recent case of a 29 year old woman with brain cancer has again raised questions about the right to die. Americans are divided on whether doctors should be able to give deathly sick patients drugs to end their lives. Only four U.S states permit doctor, or physician, assisted suicide. More

Practice Your Writing

Confessions of an English Learner BlogConfessions of an English Learner Blog

Tell us About Our Programs