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Vitamin Guide
The American Dietetic Association provides the following information
on vitamins.
Our bodies need at least 13 vitamins to function:
Vitamin A:
Functions: Vitamin A is a fat-soluble vitamin that helps you see
normally in the dark and promotes the growth and health of all body
cells and tissues. It also protects against infection by keeping healthy
the skin and tissues in the mouth, stomach, intestines and respiratory
and uro-genital tract.
Deficiency problems: Night blindness and other eye problems; dry,
scaly skin, problems with reproduction, poor growth.
Food sources: Liver, fish oil, eggs, milk fortified with vitamin A; red, yellow and orange fruits and vegetables, many dark-green, leafy
vegetables.
Excess amounts: Can lead to birth defects, headaches, vomiting, double vision, hair loss, bone abnormalities and liver damage.
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Vitamin D (calciferol):
Functions: Vitamin D is a fat-soluble vitamin that promotes the
absorption of calcium and phosphorus and helps deposit these
minerals in bones and teeth to make them strong.
Deficiency problems: Greater risk of osteoporosis and
osteomalacia (softening of the bones). Children can develop rickets
or defective bone growth.
Sources: Vitamin D is known as the "sunshine" vitamin, because
your body can produce it after sunlight or ultraviolet light hits the
skin. Food sources include cheese, eggs, some fish (such as
salmon and sardines), fortified milk, breakfast cereals and margarine.
Excess amounts: Can lead to kidney stones or kidney
damage, weak muscles and bones, excessive bleeding and other
problems. Excessive amounts usually come from supplements, not
food or overexposure to sunlight.
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Vitamin E (tocopherol):
Functions: Vitamin E is a fat-soluble vitamin what works as an
antioxidant and, as such, may have a possible role in protecting
against illnesses such as heart disease and some types of cancer.
Deficiency problems: Nervous system problems. Deficiencies are
very rare, as vitamin E is abundant in foods. Premature, very low
birthweight babies and people who do not absorb fat normally may
have deficiency problems.
Food sources: Vegetable oils and margarine, salad dressing and
other foods made from vegetable oils, nuts, seeds, wheat germ,
leafy-green vegetables.
Excess amounts: May interfere with vitamin K action and
enhance the effect of some anticoagulant drugs.
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Vitamin K:
Functions: Vitamin K is a fat-soluble vitamin that helps blood to clot
and stop bleeding.
Deficiency problems: Thin blood that does not adequately
coagulate.
Food sources: Intestinal bacteria produce some of the vitamin K
you need. The best food sources include green leafy vegetables
such as kale, parsley, spinach and broccoli. Smaller amounts are
found in milk and other dairy products, meat, eggs, cereal, fruits and
other vegetables.
Excess amounts: No symptoms have been observed from excessive intake of vitamin K.
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Vitamin C (ascorbic acid):
Functions: Vitamin C is a water-soluble vitamin that helps the body
absorb iron out of food made from plant sources. It helps produce
the connective tissue collagen, helps form and repair red blood cells,
bones and other tissues, helps keep capillary walls and blood
vessels firm, protects against bruising, helps maintain healthy gums
and heal cuts and wounds, helps protect from infection by keeping
the immune system healthy.
Deficiency problems: Scurvy, a disease that causes loose teeth,
Excessiveive bleeding, swollen gums and improper wound healing.
Scurvy is rare in the United States.
Food sources: Citrus fruits and many other fruits and vegetables,
including berries, melons, peppers, many dark-green leafy
vegetables, potatoes and tomatoes.
Excess amounts: Vitamin C intake may cause diarrhea and gastrointestinal
discomfort. Use of supplements can also interfere with tests for
blood sugar level.
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Thiamin (vitamin B1):
Functions: Thiamin is a water-soluble vitamin that helps all body
cells produce energy from carbohydrates.
Deficiency problems: Alcoholics are frequently low in thiamin and
suffer fatigue, weak muscles and nerve damage as a result.
Food sources: Whole-grain and enriched grain products, such as
bread, rice, pasta, tortillas, fortified breakfast cereals, pork, liver and
other organ meats.
Excess amounts: Excessive intake of thiamin is expelled in the urine.
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Riboflavin (vitamin B2):
Functions: Riboflavin is a water-soluble vitamin which helps all body
cells produce energy and change tryptophan (an amino acid) into
niacin (another B vitamin).
Deficiency problems: Severely malnourished people may suffer eye
disorders (such as cataracts), dry and flaky skin, and a sore red
tongue.
Food sources: Milk and other dairy products, enriched bread,
cereal and other grain products; eggs, meat, green leafy vegetables,
nuts, liver, kidney and heart.
Excess amounts: No problems have been linked to excessive riboflavin intake.
FYI: Ultraviolet light destroys riboflavin.
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Niacin
Functions: Niacin is a water-soluble vitamin that helps the body use
sugars and fatty acids, and helps all body cells produce energy. It
also helps enzymes function in the body.
Deficiency problems: Symptoms include diarrhea, mental
disorientation and skin problems.
Food sources: Some niacin is produced in the body. Foods high
in protein, such as poultry, fish, beef, peanut butter and legumes, are
also usually good sources.
Excess amounts: Excessive intake of nicotinic acid (a form of niacin), which usually only occurs with supplements, may cause flushed skin, liver damage, stomach ulcers and high blood sugar.
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Vitamin B6 (pyridoxine):
Functions: Vitamin B6 is a water-soluble vitamin which helps the
body make proteins, which are then used to make body cells. It also
helps convert tryptophan (an amino acid) into niacin and serotonin
(a brain chemical). Vitamin B6 also helps produce other body
chemicals such as insulin, hemoglobin and antibodies to fight
infection.
Deficiency problems: Depression, nausea, mental convulsions in
infants and greasy, flaky skin.
Food sources: Chicken, fish, pork, liver, kidney, whole grains, nuts
and legumes.
Excess amounts: Can cause nerve damage.
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Folate (folacin or folic acid):
Functions: Folate is a water-soluble vitamin which plays an
essential role in producing DNA and RNA to make new body cells. It
also works with vitamin B12 to form hemoglobin in red blood cells.
Deficiency problems: Impaired cell division and growth, a type of
anemia, and, during the first trimester of pregnancy, increased risk of
delivering a baby with neural tube defects including spina bifida.
Food sources: Leafy vegetables, orange juice and some fruits,
legumes, liver, yeast breads, wheat germ and some fortified cereals.
Excess amounts: May interfere with medications and cause
convulsions in people with epilepsy. It can also mask vitamin B12
deficiencies, leading to permanent nerve damage if not treated with
vitamin B12.
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Vitamin B12 (cobalamin):
Functions: Vitamin B12 is a water-soluble vitamin which works with
folate to make red blood cells. It also serves in body cells as a
vital part of many body chemicals and helps the body use fatty acids
and some amino acids.
Deficiency problems: Anemia, fatigue, nerve damage, a smooth
tongue, very sensitive skin. B12 deficiencies may be hidden when
extra folate is taken to treat or prevent anemia. Strict vegetarians
who eat no animal products and their infants are the most likely to
develop vitamin B12 deficiencies. People who do not absorb
vitamin B12 may also be deficient.
Food sources: Animal products and some fortified foods.
Excess amounts: No problems are associated with excessive intake of vitamin B12.
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Biotin
Functions: Biotin is a water-soluble vitamin which helps all body
cells produce energy. It also helps metabolize protein, fat and
carbohydrates in food.
Deficiency problems: Heart abnormalities, appetite loss, fatigue,
depression and dry skin.
Food sources: Eggs, liver, yeast breads and cereals.
Excess amounts: No problems have been linked to excessive intake of biotin.
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Pantothenic Acid:
Functions: Pantothenic acid is a water-soluble vitamin which helps
all body cells produce energy. It also helps metabolize protein, fat
and carbohydrate in food.
Deficiency problems: Rare in healthy people who eat a balanced
diet.
Food sources: Meat, poultry, fish, whole-grain cereals and legumes
are among the best sources. Milk, vegetables and fruits also contain
varying amounts.
Excess amounts: May cause occasional diarrhea and water retention.
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