Healthy Eating: Valuable Vitamins
In This Article:
Vitamin B12 works closely with folic acid to form red blood cells. It also helps maintain the nervous system and is essential for the normal functioning of all body cells. Vitamin B12 is necessary in assisting the body to use fat and some amino acids.
A deficiency of vitamin B12 can result in anemia, fatigue, nerve damage, smooth tongue, and very sensitive skin. It is important to know that a deficiency of this vitamin can be hidden, and even progress, if extra folic acid is taken to treat or prevent anemia.
ALERT! Since B12 is found mostly in animal products, strict vegetarians and infants are at risk of developing a B12 deficiency. Including fortified foods and/or dietary supplements daily can help prevent this.
The classic deficiency symptom of vitamin B12 is anemia. This vitamin cannot be absorbed without the help of a substance called the intrinsic factor. Because this intrinsic factor is made in the lining of the stomach, the elderly and people with gastrointestinal disorders may not absorb the vitamin B12 their body needs. There are also people who, for either medical or genetic reasons, are missing this intrinsic factor. This problem can usually be treated with B12 injections. When anemia is caused by a lack of the intrinsic factor, it is called pernicious anemia. When the anemia is caused by poor dietary intake, it is called macrocytic anemia. Because of the body's ability to store vitamin B12, and because of the small amount needed daily, a deficiency can take years to develop. There are no known toxic effects of taking large doses of vitamin B12, but neither is there any scientific evidence that extra vitamin B12 helps boost energy. Vitamin B12 has no established UL.
Foods rich in vitamin B12 include meat, fish, poultry, eggs, milk and other dairy foods, and fortified foods.
Folic Acid (Folacin or Folate)
Folic acid's main role is to maintain the cell's genetic code—DNA, the master plan for cell reproduction. It also works with vitamin B12 to form hemoglobin in red blood cells.
In recent years, folic acid has gained much attention for its role in reducing the risk for neural tube birth defects, such as spina bifida, in newborn babies. The embryo's neural tube is what becomes the spinal cord. It is vital that pregnant women or women of childbearing years consume enough folic acid through food and supplements, especially during the first trimester. Other deficiencies of folic acid include anemia, impaired growth, and abnormal digestive function. Taking too much folic acid through supplements can mask a vitamin B12 deficiency and could interfere with other medications. In the synthetic form—the form used to fortify foods and in supplements—folic acid has a UL of 1,000 mcg per day for adults over eighteen.
Fact: Most enriched-grain products now have to be fortified with folic acid, according to a new FDA regulation. This is to help ensure that women get enough folic acid to help prevent neural tube birth defects during pregnancy.
Foods rich in folic acid include some fruits, such as oranges, as well as leafy vegetables, legumes, liver, wheat germ, some fortified cereals, avocados, and enriched-grain products.
Biotin participates in the metabolism of the macronutrients for energy and helps your body produce energy in the cells. For people who eat a healthy, well-balanced diet, deficiency is not a problem. In the rare cases when deficiency does occur, symptoms include heart abnormalities, loss of appetite, fatigue, depression, and dry skin. Biotin has no known toxic effects and no established UL.
This vitamin is found in a wide variety of foods, such as eggs, liver, yeast breads, cereals, wheat germ, and oatmeal.
Like biotin, pantothenic acid also participates in the metabolism of the macronutrients for energy and helps your body produce energy in the cells. In addition, pantothenic acid functions in the production of some hormones and neurotransmitters in the brain.
Deficiency is rare in those who eat a healthy, well-balanced diet. When deficiency does occur, symptoms include nausea, fatigue, and difficulty sleeping. The only possible effects of consuming too much pantothenic acid are occasional diarrhea and water retention. Pantothenic acid has no established UL.
Foods rich in pantothenic acid include meat, poultry, fish, whole-grain cereals, legumes, yogurt, sweet potatoes, milk, and eggs.
Vitamin C (Ascorbic Acid)
Vitamin C is often associated with warding off the common cold. There is no conclusive data that large doses of vitamin C prevent colds; they may reduce the severity or duration of symptoms, but there is no definitive evidence. Scientific evidence does not suggest taking large doses of vitamin C on a regular basis to boost immunity or to decrease risks for the common cold.
But vitamin C does have some very important functions. Vitamin C produces collagen, a connective tissue that holds muscles, bones, and other tissues together. It also helps form and repair red blood cells, bones, and other tissue; helps protect you from bruising by keeping capillary walls and blood vessels firm; helps keep your gums healthy; helps heal cuts and wounds; and helps keep your immune system strong and healthy. Vitamin C helps your body absorb iron from plant sources, which is not as easily absorbed as iron from animal foods. Vitamin C is one of the very powerful antioxidants. As an antioxidant, vitamin C attacks free radicals in the body's fluids.
Essential: Cigarette smokers need at least twice as much vitamin C as nonsmokers, that is, at least 100 milligrams per day.
Since vitamin C is so widely available in our foods, deficiency is rare. Possible deficiency symptoms include poor wound healing, higher susceptibility to infections, bleeding gums, hemorrhaging, and, in severe cases, scurvy. Scurvy is a disease characterized by bleeding and swollen gums, joint pain, muscle wasting, and bruising.
Because vitamin C is a water-soluble vitamin, your body excretes the excess that may be consumed. Very large doses, though, could cause kidney stones, nausea, and diarrhea. The effects of taking large amounts over extended periods of time are not yet known. Vitamin C has a UL set at 2,000 mg per day for adults over eighteen.
Most fruits and vegetables are great sources of vitamin C. These include all citrus fruits, berries, melons, peppers, dark green leafy vegetables, potatoes (especially the skin), and tomatoes.
More on: Nutritional Resources for Families
Copyright © 2002 by Kimberly A. Tessmer. Excerpted from The Everything Nutrition Book: Boost Energy, Prevent Illness, and Live Longer with permission of its publisher, Adams Media Corporation.
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