We hear a lot about vitamins, but many people aren't aware of the specific roles they play in keeping us healthy. Vitamins are complex organic substances that are essential for a healthy metabolism. Vitamins are found in minute quantities in food. Some, like vitamin D, can be produced by the human body. Vitamin deficiencies can cause serious health problems. (Scurvy is a famous example caused by a lack of Vitamin C. It used to plague sailors at seas, especially before people properly understood nutrition.)
There are two Major categories of vitamins. Fat soluble vitamins include vitamin A, vitamin D, vitamin E, and vitamin K. Water soluble vitamins include vitamin C and the group of molecules known as the vitamin B complex. Both fat soluble and water soluble vitamins are important for healthy living.
Here are some interesting details about the more well known vitamins.
Vitamin A
Vitamin A, a fat-soluble vitamin, plays an important role in eyesight, especially with regards to night vision. Vitamin A is also involved in the formation and maintenance of healthy skin, hair, and mucous membranes. In addition, it is necessary for proper bone growth, tooth development, reproduction and for the development of epithelial cells.
Vitamin A can be found in eggs, milk, carrots, spinach, sweet potatoes, fish oil, liver, butter, broccoli, apricots, nectarines, cantaloupe, and orange or yellow vegetables and fruits.
A vitamin A deficiency can cause night blindness and dry skin.
Vitamin B
Vitamin B is a complex of several different vitamins including B1, B2, B6, B12, niacin, folic acid, biotin and pantothenic acid. These are very important for metabolic activity and in the health of red blood cells. They also help your body make protein and energy.
The sources of vitamin B are leafy green vegetables, seafood, beans, peas, citrus fruits, whole grains, poultry, meats, eggs and dairy products. Some bacteria in our large intestine prepare some type of B-vitamins.
A vitamin B deficiency can cause Beri Beri, cracked lips, weak muscles, and malformation of red blood cells.
Vitamin C
Vitamin C, or ascorbic acid, is a water soluble antioxidant that is used in the production of collagen, a protein that gives structure to bones, cartilage, muscle, and blood vessels. It helps keep body tissues, such as gums and muscles, in good shape and assists in the healing of wounds. It also helps to protect vitamins A, E and fatty acids from oxidation.
Vitamin C is found in citrus fruits, cantaloupe, strawberries, tomatoes, broccoli, cabbage and other fresh fruits and vegetables.
A vitamin C deficiency affects the health of skin. It can cause poor wound healing and lead to scurvy which causes bleeding in gums, easy bruising, bumps of coiled hair on the arms and legs, pain in the joints, muscle wasting, and other problems.
Vitamin D
Vitamin D is a fat soluble vitamin that regulates the formation of bone and the absorption of calcium and phosphorus from the intestine. It helps to control the movement of calcium between bone and blood, and vice versa.
Vitamin D can be found in fish liver oil, egg yolks, milk and other dairy products fortified with vitamin D. It is also produced in our body in the presence of ultra violet light, such as from sunlight.
A vitamin D deficiency can cause weak bones and bowed legs (in children). Its excess can cause loss of appetite, weight loss, nausea, headache, depression and deposits of calcium in the kidneys.
Vitamin E
Vitamin E, one of the fat soluble vitamins, is essential for the inhibition of oxidation in body tissues, the formation of red blood cells and prevents the breakdown of body tissue. It helps to protect the lungs from pollution.
Vitamin E can be found in whole grains, wheat germ, leafy green vegetables, sardines, egg yolks, nuts, bread, cereals and seeds.
A vitamin D deficiency can cause cancer, diabetes, heart disease and Alzheimer's disease.
This is just a brief introduction. For further information, you might enjoy visiting The Reference Guide for Vitamins.