Vitamins
The word “vitamin” goes back to the Polish scientist Casimir Funk in 1912. He was studying a substance in the layer that covers rice. This substance was believed to cure a disease 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.
Scientists have discovered fourteen 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 in cells. If we do not get enough of the vitamins we need in our food, we may develop a number of diseases.
This brings us back to Casmir 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 investigated 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 lost some of its strength. 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 twelve 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.
Types of Vitamins
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. Their eys may get dry. 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 well. Without it, we would be weak and would not grow. We also might develop beriberi. Apart from rice thiamine is found in beans , peas, nuts, 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 helps produce red blood cells. It is found naturally in foods such as eggs, meat, fish and milk products. It also helps babies of pregnant mothers before they are born . Vitamin B-12 is found in green leafy vegetables and other foods and citrus fruits. In some countries, it is added to products like bread.
Vitamin C is needed for strong bones and teeth, and for healthy blood. It also helps wounds heal quickly. Because our body stores little vitamin C we must get it every day in foods such as citrus fruits, tomatoes and cabbage.
Vitamin D helps make calcium in the blood. Calcium is needed for nerve and muscle cells to work normally. It also is needed to build strong bones. 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, and spinach.
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 or vitamin supplements will improve their health and protect them from disease.
Experts note that taking too much of some vitamins can be harmful. People should be sure to discuss what vitamins they take with their doctors. This is because some vitamins can cause harmful effects when mixed with medicines.
Online Exercises
Downloadable PDF Text- and Worksheets
Words
- amount =how much of something
- bean =green or yellow seeds that come from a climbing plant and are used as food
- beriberi = a disease of the nerves that you get if you don't get enough vitamins
- bleeding = when you lose blood form your body
- cabbage = a large round vegetable with thick green and purple leaves
- cause =lead to
- contain = have
- cure = to make an illness go away
- develop = grow
- discover = to find for the first time
- disease = illness
- fail = here: not to do something
- harmful = dangerous
- heal = to grow back together
- improve = to get better
- intestine = the long tube in your body through which food passes after it goes through your stomach
- investigate = to try to find out how something works or the cause of something
- involve = here: to be a part of something
- leafy = looks like a leaf
- lemon = a fruit with a hard yellow skin ; it is sour
- light-sensitive =it reacts to very small changes of light
- necessary = very important and needed
- nervous system =all of your nerves in the body, brain and back with which your body feels pain; your movements are controlled here
- note = say
- pea = round green seed that can be cooked and eaten as a vegetable
- pork = meat from a pig
- prevent = to stop something from happening
- scientist =a person who is trained in science
- scurvy = a disease that you get by not eating food that gas vitamin C
- spinach = a vegetable with large dark green leaves
- starchy =food that has carbohydrates in it or a substance which gives you energy
- store = to keep something in a place and get it when you need it
- substance =material
- thicken = to make thicker
- tissue = parts of the body that exist between or join organs and other body parts
- vitamin supplement = something that you take that has the same effects as if you ate food with real vitamins
- wound =an injury to your body