Vitamins are natural organic substances essential for the proper regulation of reproduction, growth, health, and energy production. Humans are unable to manufacture most of the necessary vitamins and these must be obtained from dietary sources, either as whole foods or supplements.
Beta Carotene, a naturally occurring orange pigment found in plants such as carrots, squash, and pumpkins, is a powerful fat-soluble antioxidant that heps neutralize free radicals, prevents cancer, and fights infectious diseases. Beta carotene, referred to as provitamin A, is transformed into vitamin A in the body. This unique feature means that beta carotene is non-toxic at doses ranging as high as 500,000 iu, whereas vitamin A retinol can produce toxic effects in relatively low doses.
Adequate intake of beta carotene has been shown to help prevent Xerophthalmia (night blindness). In addition to promoting good vision, beta carotene also protects the heart and cardiovascular system, boosts immune functions, speeds recovery from respiratory infections such as colds and flu, and promotes wound healing.
Researchers are now focused on beta carotene’s impressive ability to quench singlet oxygen free radicals, leading to a greater understanding of its role in slowing down the aging process, preventing the formation of tumors, and possibly reversing the course of certain forms of cancer. A recent study presented at an American Cancer Society seminar found that beta carotene was able to reduce by half the number of precancerous mouth lesions in over 53% of test subjects diagnosed with precancerous mouth lesions.
NEW RESEARCH: Beta carotene is a nutrient found in the most abundance in yellow and dark green fruit and vegetables-foods like apricots, squash, cantaloupe, broccoli, spinach, and sweet potatoes. Its ability to prevent heart attacks came as a surprise to Dr. Charles Hennekens of Boston’s Brigham and Women’s Hospital, who was really interested in studying beta carotene’s cancer-fighting capacity. In 1990, nearly halfway through a 10-year study, Hennekens looked specifically at the data from 333 of the 22,000 men in this Physicians’ bob电竞投注平台 Study. These men were selected because they all had evidence of coronary artery disease, including angina, (the chest pain that occurs when the arteries that serve the heart are obstructed) at the start of the study.
After 6 years, 27 of the 333 men had suffered heart attacks: 10 in the group taking 50 mg (83,350 IU) of beta carotene every other day, and 17 in the group taking the placebo, representing an almost 40% lower risk for the beta carotene group. Among the men taking both beta carotene and aspirin, there were no heart attacks at all. In fact, Hennekens reported, those men taking the 50-mg dose of beta carotene had about half the number of heart attacks, strokes, cardiac arrests, or operations to open or bypass clogged arteries.1
It seems to be beta carotene’s antioxidant capacity — specifically its ability to prevent the oxidation of cholesterol — that explains its protective role in heart disease. Recent evidence has shown that cholesterol is most dangerous after it has been oxidized or damaged, thus releasing free radicals into the bloodstream, where they can damage delicate arteries. These sites of damage attract the fatty deposits that eventually clog the arteries. Free radicals may also oxidize low-density lipoprotein (LDL) cholesterol (the “bad” cholesterol), which makes the macrophages transporting the LDL turn into foam cells that form atherosclerotic plaques.
Folic Acid is a water soluble nutrient belonging to the B-complex family. The name folic acid is derived from the latin word “folium”, so chosen since this essential nutrient was first extracted from green leafy vegetables, or foliage. Sometimes referred to as vitamin M, folic acid was originally extracted from spinach in 1941 and was found to be an effective treatment for macrocytic anemia.
Among its various important roles, folic acid is a vital coenzyme required for the proper synthesis of RNA and DNA, the nucleic acids that maintain our genetic codes and insure healthy cell division. Adequate levels of folic acid are essential for energy production and protein metabolism, for the formulation of red blood cells, and for the proper functioning of the intestinal tract.
Of great import are recent studies connecting folic acid intake with the incidence of spinal closure problems in newborn babies. bob电竞投注平台 workers have long known that folic acid is required for the proper regulation and development of embryonic fetal nerve cells during the early stages of pregnancy. Now researchers have found an almost complete reduction in the incidence of spinal closure problems such as spina bifida in babies born to women with a daily folic acid intake of at least 400 micrograms.
Folic acid may also prove to be effective in the prevention and treatment of uterine cancer. A deficiency of folic acid causes cellular damage resembling the initial stages of uterine cervical dysplasia. Researchers discovered that women taking folic acid supplements have fewer precancerous cervical cells compared to women with low intake of folic acid. Evidence suggests that folic acid works by inhibiting the progression of abnormal cells into cancer cells and may even help return the damaged tissues to healthy condition.
Folic acid deficiency affects all cellular functions, but most importantly it reduces the body’s ability to repair damaged tissues and grow new cells. Tissues with the highest rate of cell replacement, such as red blood cells, are affected first, leading to anemia. Folic acid deficiency symptoms include a sore tongue, cracking at the corners of the mouth, gastro-intestinal distress, diarrhea, and poor nutrient absorption and malnutrition leading to stunted growth, weakness and apathy.
The current Recommended Daily Allowance for folic acid is 180 to 200 micrograms per day. This allowance is controversial as it is based more on politics than science. Studies have consistently shown that the average American gets less then half the previously recommended RDA of 400 micrograms per day for adults and 800 micrograms per day for pregnant women. Unable to make the great leap to suggest that people should take supplements to confer the protection offered by folic acid, government officials instead simply decided to lower the RDA.
Folic acid deficiency is a common vitamin deficiency that can develop within a few weeks to months of lowered dietary intake. Those with the greatest need for increased folic acid intake include people under mental and physical stress, including disease, alcoholics, and people taking oral contraceptives, aspirin, and anticonvulsants. Foods highest in folic acid include barley, beans, beef, bran, brewers yeast, brown rice, cheese, chicken, tuna, milk, salmon, wheat germ, whole grains, and green leafy vegetables.
Though not generally regarded as toxic, large doses of folic acid can cause allergic skin reactions, and should be avoided by people being treated for hormone related cancers. High doses of folic acid can also cause problems convulsions in people taking the drug phytoin for a convulsive disorder.
Biotin is a water-soluble vitamin and member of the B-complex family. Originally isolated in 1901, over the years numerous researchers attached different names to this nutrient, referring to it alternately as bios, vitamin H, protective factor X, and coenzyme R. Today the scientific name for this sulfur-bound vitamin is biotin.
Biotin is an essential nutrient that is required for cell growth and for the production of fatty acids. Biotin also plays a central role in carbohydrate and protein metabolism and is essential for the proper utilization of the other B-complex vitamins. Biotin contributes to healthy skin and hair, and may play a role in preventing hair loss.
A biotin deficiency of is rare, as biotin is easily synthesized in the intestines by bacteria, usually in amounts far greater than are normally require for good health. Those at highest risk for biotin deficiency are people with digestive problems that can interfere with normal intestinal absorption, and those taking antibiotics or sulfa drugs, which can inhibit the growth of the intestinal bacteria that produce biotin. Consuming raw eggs in large amounts over a prolonged period can contribute to biotin deficiency, as eggs whites contain a protein called avidin, that binds to biotin and interfere with its absorption. This is not a problem when consuming cooked eggs, which are a good dietary source of biotin.
Some symptoms of biotin deficiency are depression, lethargy, eczema, dermatitis, anorexia, nausea, vomiting, inflammation of the tongue, and muscle pain. Infants with seborrheic dermatitis, evidenced by dry and scaly face and scalp, may also be suffering from a biotin deficiency.
The adult Recommended Daily Allowance for biotin is 300 micrograms. Natural sources highest in biotin include liver, egg yolks, brewer’s yeast, salt-water fish, milk, soybeans, and rice. Biotin is also found in virtually all B-complex supplements in doses ranging from 25 micrograms to 300 micrograms. There are no known toxic levels or symptoms for biotin.
Vitamin A is a vital fat-soluble nutrient and antioxidant that can prevent night blindness, maintain healthy skin, and confer protection against cancer and other diseases. Vitamin A is commonly found in two forms; as preformed vitamin A, also referred to as retinol, and as provitamin A, or beta carotene.
Vitamin A deficiency can lead to Xerophthalmia or night blindness, a deficiency disease that most commonly affects children in third-world countries. Early signs of Vitamin A deficiency are gradual loss of night vision, roughened skin and defective formation of bones and teeth. If left untreated Xerophthalmia can result in complete blindness.
In addition to promoting good vision, other recognized major benefits of vitamin A include its ability to protect the heart and cardiovascular system, boost the immune system, speed recovery from respiratory infections, promote wound healing, slow down the aging process, and prevent and possibly reverse the course of certain forms of cancer. Vitamin A also plays an important role in maintain healthy skin. Most current popular acne and psoriasis treatments on the market, such as Retinol and Accutane, are based on vitamin A or its derivatives.
Retinol is derived from animal sources, primarily fish liver oils, and is easily destroyed by exposure to heat, light, and oxygen. When examining your vitamin formula to determine Vitamin A levels expect to see vitamin A referred to in its palmitate or acetate forms, which are preferred by manufacturers.
The Recommended Daily Intake of vitamin A is 5,000 International Units or 1,000 Retinol Units. As a supplement, vitamin-A is available in capsules ranging from 5,000 to 10,000 iu or International Units. Excessive intake of vitamin A can lead to dangerous toxic symptoms, including hair loss, nausea, scaly skin, bone pain, fatigue, blurred vision, and liver enlargement. For this reason many prefer to take Beta Carotene, also referred to as provitamin A, which offers all the proven benefits of vitamin A with none of the adverse side effects.
Vitamin B-1, also called thiamine, is a nutrient critical for maintaining a healthy central nervous system. Addequate thiamine levels can dramatically affect mental functions by helping us maintain a positive mental attitude and by enhancing our learning abilities. Conversely, inadequate levels of B1 can lead to eye weakness, mental confusion, and loss of physical coordination.
Vitamin B1 is required for the production of hydrochloric acid, for forming blood cells, and for maintianing healthy circulation. It also plays a key role in converting carbohydrates into energy, and in maintaining good muscle tone of the digestive system and the heart.
Like all the B-vitamins, B-1 is a water soluble nutrient that cannot be stored in the body, but must be replenished on a daily basis. B-1 is also synergistic, meaning that it is most effective when taken in a balanced complex of the other B vitamins.
A chronic deficiency of thiamin will lead to a beriberi, a devastating and potentially deadly disease of the central nervous system. Due to improved diets and widespread use of inexpensive supplements, beriberi is extremely rare in the developed nations, with one important exception. Beriberi symptoms are frequently found in chronic alcoholics due to the destructive effect alcohol has on B1. Thiamine levels can also be affected by ingestion of antibiotics, sulfa drugs, caffeine, antacids, and oral contraceptives. A diet high in carbohydrates can also increase ones need for B1.
Food sources high in thiamin include dried beans, eggs, brewers yeast, whole grains, brown rice, and seafood. In supplemental form, B-1 is generally found in a combination with vitamins B-2, B-3, B-6, pantothenic acid, and folic acid. There are no known toxic effects from vitamin B-1, and any excess is simply excreted from the body. The Recommended Daily Amount for B-1 is 1.5 milligrams, though more typical daily intake ranges from 50 to 500 milligrams per day.
Vitamin B-2, also known as Riboflavin, is an easily absorbed, water-soluble micronutrient with a key role in maintaining human health. Like the other B vitamins, riboflavin supports energy production by aiding in the metabolization of fats, carbohydrates and proteins. Vitamin B-2 is also required for red blood cell formation and respiration, antibody production, and for regulating human growth and reproduction. Riboflavin is known to alleviate eye fatigue, prevent and treat cataracts, increase energy levels, and aid in boosting immune system functions. It also plays a key role in maintaining healthy hair, skin and nails, and in combination with vitamin B-6, forms part of an effective treatment for carpal tunnel syndrome.
A deficiency of vitamin B-2 may be indicated by the appearance of cracks and sores at the corners of the mouth, a swollen and sore tongue, reddening of the lips, and the appearance of scaly, oily, inflamed skin. Use of oral contraceptives can dramatically increase the need for riboflavin, as does strenuous exercise. Pregnant women need to pay particular attention to assure they have adequate levels of B2 which are critical for the proper growth and development of the baby.
Foods high in vitamin B2 include beans, cheese, eggs, fish, meat, milk, poultry, spinach, and yogurt. In supplement form, B-2 is usually found in a complex combined with vitamins B-1, B-3, B-6, pantothenic acid, and folic acid.
Recommended Daily Intake for B2 is 1.2 mg. to 1.7 mg. per day. For pregnant women, the RDA is 1.6 mg per day, and 1.8 mg. per day for the first 6 months of nursing. RDA’s aside, the common doses available on the market range from 100 to 300 mg per day. There are no known toxic effects for B-2, but large doses can lead to tingling in the extremities and an increased sensitivity to sunlight.
Vitamin B-3, also called Niacin, Niacinamide, or Nicotinic Acid, is an essential nutrient required by all humans for the proper metabolism of carbohydrates, fats, and proteins, as well as for the production of hydrochloric acid for digestion. B3 also supports proper blood circulation, healthy skin, and aids in the functioning of the central nervous system. Because of its role in supporting the higher functions of the brain and cognition, vitamin B3 also plays an important role in the treatment of schizophrenia and other mental illnesses. Lastly, adequate levels of B-3 are vital for the proper synthesis of insulin, and the sex hormones such as estrogen, testosterone, and progesterone.
A deficiency in vitamin B-3 can result in pellagra, a disorder characterized by malfunctioning of the nervous system, gastrointestinal upset, diarrhea, dementia, depression, and severe dermatitis and skin leasions. Recently Niacin has been embraced by the medical community for its ability to safely lower elevated blood cholesterol and triglyceride serum levels without harmful side-effects. Due to the large amounts of niacin used, it is best to undertake such a proram only in close partnership with your physician.
High doses of niacin may result in a niacin flush, a natural allergic reaction that is harmless, but can be uncomfortable if inexpected. A niacin flush will generally result in a burning, tingling, and itching sensation, accompanied by a reddening flush, that spreads across the skin of the face, arms and chest. This effect is harmless and will pass within 20 minutes to an hour. Drinking a glass of water will also speed relief if too much niacin has been consumed.
High amounts should be used with caution by those who are pregnant and megadoses of pure niacin may aggravate health problems, such as stomach ulcers, gout, glaucoma, diabetes mellitus, and liver disease. Again, check with your physician before taking doses of niacin greater than 1,000 mg. per day. Natural food sources for Vitamin B3 include beef, broccoli, carrots, cheese, corn flour, eggs, fish, milk, potatoes and tomatoes.
Vitamin B-5 (Pantothenic Acid) is a B vitamin named after the Greek word pantos, meaning “everywhere” because it is found in both plant and animal food sources. Pantothenic acid is a water-soluble B vitamin that cannot be stored in the body but must be replaced daily, either from diet or from supplements.
Pantothenic acids’ most important function is as an essential component in the production of coenzyme A, a vital catalyst that is required for the conversion of carbohydrates, fats, and protein into energy. Pantothenic acid is also referred to as an antistress vitamin due to its vital role in the formation of various adrenal hormones, steroids, and cortisone, as well as contributing to the production of important brain neuro-transmitters such as acetylcholine. In addition to helping to fight depression Pantothenic acid also supports the normal functioning of the gastrointestinal tract and is required for the production of cholesterol, bile, vitamin D, red blood cells, and antibodies.
There is no specific deficiency disease associated with inadequate intake of pantothenic acid, though under severe dietary conditions a lack of B5 can lead to a variety of symptoms including hypoglycemia, skin disorders, fatigue, depression, digestive problems, lack of coordination and muscle cramps. The current RDA for pantothenic acid is 10 mg.
Pantothenic acid is found in a wide variety of foods including beans, beef, liver, salt-water fish, chicken, cheese, eggs, whole grain breads and cereals, avocados, cauliflower, green peas, beans , nuts, dates, and potatoes. Most common B-complex formulas contain from 10 to 100 mg. of B5, though daily doses up to 1000 mg are not uncommon, especially for treatment of arthritis and allergies.
Vitamin B-6, also called Pyridoxine, refers to a family of closely related water soluble substances that include pyridoxine, pyridoxal and pyridoxamine. Vitamin B6 is a water soluble nutrient that cannot be stored in the body, but must be obtained daily from either dietary sources or supplements.
Vitamin B6 is an important nutrient that supports more vital bodily functions than any other vitamin. This is due to its role as a coenzyme involved in the metabolism of carbohydrates, fats, and proteins. Vitamin B6 is also responsible for the manufacture of hormones, red blood cells, neurotransmitters, enzymes and prostaglandins. Vitamin B6 is required for the production of serotonin, a brain neurotransmitter that controls our moods, appetite, sleep patterns, and sensitivity to pain. A deficiency of vitamin B6 can quickly lead to insomnia and a profound malfunctioning of the central nervous system.
Among its many benefits, vitamin B6 is recognized for helping to maintain healthy immune system functions, for protecting the heart from cholesterol deposits, and for preventing kidney stone formation. B6 is also effective in the treatment of carpal tunnel syndrome, premenstrual syndrome, night leg cramps, allergies, asthma and arthritis.
Common symptoms of vitamin B6 deficiency can include depression, vomiting, anemia, kidney stones, dermatitis, lethargy and increased susceptibility to diseases due to a weakened immune system. Infants suffering from vitamin B6 deficiency can be anxious and irritable, and in extreme cases may develop convulsions.
Supplemental B6 is a commonly used as a treatment for nausea, morning sickness and depression. Pregnant women have an increased need for supplemental vitamin B6, as do patients suffering from heart disease or those undergoing radiation treatment. Persons on high protein diets require extra vitamin B6, as do those taking antidepressants, amphetamines, oral contraceptives, and estrogen.
Natural foods highest in vitamin B6 include brewers yeast, carrots, chicken, eggs, fish, avocados, bananas, brown rice, and whole grains. The RDA for vitamin B6 is 2 mg per day. Most B-complex formulas contain between 10 to 75 mg. of vitamin B6.
Vitamin B6 is one of the few vitamins that can be toxic. Doses up to 500 mg per day are uncommon but safe, but doses above 2 grams per day can lead to irreversible neurological damage unless under the treatment of a physician. Vitamin B6 supplements should not be taken by Parkinson’s disease patients being treated with L-dopa as vitamin B6 can diminish the effects of L-dopa in the brain.
Vitamin B-12, also referred to as cobalamin and cyanocobalamin, is a water-soluble compound of the B vitamin family with an unique difference — unlike other B-vitamins that must be replaced daily, vitamin B12 can be stored for long periods in the liver and kidneys.
Vitamin B12 is a particularly important coenzyme that is required for the proper synthesis of DNA which controls the healthy formation of new cells throughout the body. B12 also supports the action of vitamin C, and is necessary for the proper digestion and absorption of foods, for protein synthesis, and for the normal metabolism of carbohydrates and fats. Additionally, vitamin B12 prevents nerve damage by contributing to the formation of the myelin sheath that insulates nerve cells. B12 also maintains fertility, and helps promotes normal growth and development in children.
A deficiency of vitamin B-12 can result in a potentially fatal form of anemia called pernicious anemia. Since vitamin B12 can be easily stored in the body, and is only required in tiny amounts, symptoms of severe deficiency usually take five years or more to appear. When symptoms do surface, usually in mid-life, it is likely that deficiency was due to digestive disorders or malabsorption rather than to poor diet. The exception to this would be strict vegetarians who do not consume any foods of animal origin, since B12 only comes from animal sources.
Due to its role in healthy cell formation, a deficiency of B12 disrupts the formation of red blood cells, leading to reduced numbers of poorly formed red cells, leading to a anemia. Symptoms of anemia include fatigue, loss of appetite, diarrhea and moodiness. B12 deficiency can lead to improper formation of nerve cells, resulting in irreversible neurological damage, with symptoms ranging from disorientation, delusions, eye disorders, dizziness, confusion and memory loss.
The RDA for vitamin B12 is 2 micrograms for adults, 2.2 micrograms for pregnant women, and 2.6 micrograms for nursing mothers. Vitamin B12 is not found in vegetables, but can be found in pork, blue cheese, clams, eggs, herring, kidney, liver, seafood, and milk.
Vitamin B12 is available in supplement. Due to poor absorption in the stomach, B12 isusually taken as a sublingual or in injection form. Supplements range in strength from 50 micrograms to 2 milligrams. There are virtually no known toxic symptoms for megadoses of vitamin B12, and any excess is simply excreted from the body.
While often referred to as Vitamin B15, pangamic acid is not generally recognized as a vitamin, since there is neither an established essential need nor a well defined deficiency model for this natural water soluble compound. Originally introduced into the American nutritional market based upon research conducted by Soviet sports scientists, little if any research has been conducted in the U.S. Consequently, pangamic acid has come under scrutiny due to the controversial claims made for its effectiveness in the treatment for a wide range of diseases such as cancer, alcoholism, heart disease, drug addiction, diabetes, glandular and central nervous system disorders.
What research does exist suggests that pangamic acid acts as an antioxidant that acts synergistically when taken with vitamins A and E. This purported antioxidant property may help explain why pangamic acid is so highly touted for its ability to confer protection against urban air pollutants, extend cell life, stimulate increased immune system response, lower blood cholesterol levels, protect the liver from the ravages of alcohol, cure fatigue, ward off hangovers, and assist in the regulation of hormones.
Natural sources for pangamic acid include brewers yeast, whole brown rice, sesame seeds and pumpkin seeds. Supplemental pangamic acid obtained from apricot pits is commercially available, though FDA analysis of many commercial products claiming to contain vitamin B15 indicate that many contained no pangamic acid at all.
Common use is 50 to 150 milligrams per day. There are no known toxic effects from pangamic acid, though some users report experiencing nausea initially. This can be avoided by taking with food, preferably the largest meal of the day.
Vitamin B17, also called amygdalin, and more commonly laetrile, is one of the most controversial vitamins of the last few decades. Laetrile was originally developed in 1952 by biochemist Ernst Krebs. Krebs originally isolated laetrile from apricot pits, and with his son, began to promote it as a cancer preventative and a wonder cure, Extensive testing of laetrile by the National Cancer Institute found laetrile to be of no value as a cancer treatment, and it was further rejected by the Food and Drug Administration on the grounds it might be poisonous due to its cyanide content. This led to bitter charges by Krebs that the medical establishment and the FDA conspired in a campaign to keep his miracle compound out of the public domain.
Later reclassified by Krebs as vitamin B-17, chemically, laetrile is a compound of two sugar molecules called an amygdalin. Though it is referred to as vitamin B17, laetrile falls short of meeting established standards for consideration as a vitamin, as there there is no established metabolic need for laetrile, and there are no known deficiency symptoms when laetrile is absent from the diet.
Laetrile is a naturally occurring compound that can be found in small amounts in the seeds and pits of apricots, apples, cherries, peaches, plums, and nectarines. Laetrile contains approximately 6% cyanide, which is an extremely toxic substance. Taking excessive amounts of laetrile is dangerous, and used improperly, can be lethal.
While there is ongoing research, to date, there has been no effective proof that laetrile helps prevent or cure cancer. The main medical criticism commonly directed at laetrile is that people with potentially curable cancer may choose to take laetrile while avoiding conventional treatments, waiting until it is too late to gain benefit from effective therapy.
Vitamin C, also called ascorbic acid, is powerful water-soluble antioxidant that is vital for the growth and maintenance of all body tissues. Though easily absorbed by the intestines, vitamin C cannot be stored in the body, and is excreted in the urine within two to four hours of ingestion. Humans, along with apes and guinea pigs, are the only species on the planet incapable of synthesizing vitamin C, and must therefore have access to sufficient amounts from adequate dietary sources or supplements in order to maintain optimal health.
One of vitamin C’s most vital roles is in the production of collagen, an important cellular component of connective tissues, muscles, tendons, bones, teeth and skin. Collagen is also required for the repair of blood vessels, bruises, and broken bones.
This easily destroyed nutrient also protects us from the ravages of free radicals, dangerous unpaired oxygen fragments that are produced in huge numbers as a normal byproduct of human metabolic processes. Left unchecked, free radicals can roam the body, destroying cell membranes on contact and damaging DNA strands, leading to degenerative diseases and contributing to accelerated aging. The antioxidant activity of vitamin C can also protect us from the damaging effects of air pollution and radiation, and aid in preventing cancers. Vitamin C also inhibits the conversion of nitrites, chemicals found in foods and processed meats, into nitrosamines, dangerous cancer causing compounds that can lead to cancers of the stomach, bladder, and colon.
Vitamin C helps regulate blood pressure, contributes to reduced cholesterol levels, and aids in the removal of cholesterol deposits from arteriel walls, thus preventing atherosclerosis. Vitamin C also aids in the metabolization of folic acid, regulates the uptake of iron, and is required for the conversion of the amino acids L-tyrosine and L-phenylalanine into noradrenaline. The conversion of tryptophan into seratonin, the neurohormone responsible for sleep, pain control and well being, also requires adequate supplies of vitamin C.
A deficiency of ascorbic acid can impair the production of collagen and lead to joint pain, anemia, nervousness, retarded growth, reduced immune response, and increased susceptibility to infections. The most extreme form of vitamin C deficiency is called scurvy, a condition evidenced by swelling of the joints, bleeding gums, and the bursting, or hemorrhaging, of tiny blood vessels just below the surface of skin. If untreated scurvy is fatal. Before the discovery of lemons and limes as convenient sources of ascorbic acid, seafarers setting out on long ocean voyages could expect to lose up to two-thirds of a ships crew to scurvy. In acknowledgement of the the historical import of this well known and dreaded deficiency disease, in latin, the word ascorbic means “without scurvy”.
A recent important epidemiologic study showed that men who took vitamin C supplements lived, on average, 6 years longer than men who relied on normal dietary sources of vitamin C. This increase in life span seems to be due to a sharp reduction in heart disease. It has been estimated that if the epidemiology study is correct and everyone took just several hundred milligrams of vitamin C a day, it would save 100,000 lives and $100 billion a year in health care costs in the U.S. The recommended daily intake for vitamin c is 60 milligrams, but most health care professionals recognize that this tiny amount is barely enough to prevent the onset of scurvy, let alone confer any of the many well documented benefits of this amazing nutrient. Based on countless medical studies the therapeutic intake of ascorbic acid can be said to safely range from 500 to 4000 milligrams per day. Since this water-soluble vitamin is completely excreted from the body within 2 to 4 hours, and since the idea is to maintain stable serum levels for best results, the desired total daily dose should be divided into three separate doses and be taken throughout the day.
Foods highest in vitamin C include citrus fruits, potatoes, peppers, green leafy vegetables, tomatoes, and berries. Vitamin C is also available as a supplement in a wide range of forms such as pills, tablets, powders, wafers, and syrups. Generally doses range from 500 milligrams to 5000 milligrams depending upon the delivery system. Vitamin C activity is enhanced when taken with natural bioflavanoids such as hesperidn and rutin. Ascorbic acid works synergistically with vitamin E, meaning that both nutrients work more effectively together to extend their antioxidant effects. Ascorbyl palmitate is a fat soluble form of vitamin C that is available only in supplement form. It is a very powerful antioxidant that works to protect fats from peroxidation, and it can be stored in the body in small amounts. Ascorbyl palmitate works best when taken in combination with ascorbic acid.
The topical application of vitamin C inhibits tumor promotion in mouse skin, according to a recent study. Moreover, ascorbyl palmitate, the fat-soluble form of vitamin C, was found to be at least 30 times more effective than water-soluble vitamin C in tumor reduction in the presence of a known tumor promoter.
While the study also demonstrated that it was possible to increase levels of ascorbic acid in the skin via dietary means, that increase did not result in tumor inhibition in this study Only topically applied vitamin C (both the watersoluble and, especially, the fat-soluble forms) resulted in enhanced protection. Mice, unlike humans, can synthesize vitamin C in their bodies. The mice did not do better at the lowest dose of vitamin C, which apparently down-regulated their natural production. At higher doses, however, supplemented mice did better than unsupplemented mice. The ability to inhibit tumor-promotion in skin via dietary supplemen-tation with ascorbyl palmitate is under investigation. (Smart RC, Crawford CL. Effect of ascorbic acid and its synthetic lipophilic derivative ascorbyl palmitate on phorbol ester-induced skin-tumor promotion in mice.Am J Clin Nutr. 1991;54:1266S-12735.)
Mice that had high dietary intakes of vitamin C (ascorbic acid) and were subjected to ultraviolet (UV) light had fewer malignant skin lesions than those with lower levels of vitamin C. In a 20-week study, those mice receiving the lowest levels of dietary ascorbate developed serious malignant lesions at five times the rate of those mice fed the highest amounts of supplemental ascorbate. With a high statistical correspondence, the study showed that vitamin C was able to delay the formation of tumors induced by UV light. No toxic side effects of any sort were found with regard to the levels of vitamin C. (Pauling L. Effect of ascorbic acid on incidence of spontaneous mammal tumors and UV-light-induced skin tumors in mice. Am J Clin Nutr. 1991;54:1252S-1255S.)
While generally nontoxic, even in very large amounts, consuming vitamin C in large doses can lead to oxalic acid and uric acid stone formation unless consumed with plenty of water and supplemented with extra magnesium and vitamin B6. Taking large doses without slowly working up to the desired level can also cause temporary side effects such as diarrhea and skin rashes.
VITAMIN C AND HIV SUPPRESSION: Suppression of human immuno-deficiency virus (HIV) was found to take place in the presence of vitamin C. The near two-fold inhibition of HIV growth in Vitro required a continuous presence of non-cytotoxic amounts of either ascorbic acid or calcium ascorbate. When vitamin C was combined with NAC (N-acetyl L-cysteine), the result was a synergistic eight-fold inhibition of HIV replication. NAC is a mucolytic agent (mucous liquefier) that is structurally and functionally related to L-cysteine. This trial suggests the potential for the antiviral activity of vitamin C, especially in combination with thiol compounds such as L-cysteine, for improved control of HIV infections. (Harakeh S, Jariwalla R.J. Comparative study of the anti-HIV activities of ascorbate and thiol-containing reducing agents in chronically HlV-infected cells. Am J Clin Nutr 1991;54:S1231-1235S.)
Vitamin D is actually a family of related essential compounds, referred to as vitamins D-1, D-2, and D-3. Vitamin D is required for the proper regulation and absorption of the essential minerals calcium and phosphorus. Available primarily from animal sources, vitamin D is also commonly called the sunshine vitamin because of the body’s unique ability to synthesize Vitamin-D from brief but regular exposure to sunlight.
Adequate levels of Vitamin D are required for the proper absorption of calcium and phosphorus in the small intestines. Vitamin D further supports and regulates the use of these minerals for the growth and development of the bones and teeth. Because of this vital link, adequate intake of Vitamin D is critically important for the proper mineralization of bones and teeth in developing children. Vitamin D also aids in the prevention and treatment of osteoporosis, osteomalacia, and hypocalcemia in adults.
A prolonged Vitamin D deficiency may result in rickets, an early childhood bone disease that can produce such conditions as bowlegs and knock-knees. Common early symptoms of rickets include restlessness, profuse sweating, poor muscle tone, delayed tooth formation, and impaired development of basic motor skills such as crawling and walking. Rickets is a relatively rare disease due to the modern practice off supplementing dairy foods, such as milk, with vitamin D-2.
Osteomalacia, the adult version of vitamin D deficiency disease, can resemble osteoporosis, a bone condition characterized by an increased tendency of the bones to fracture. One important difference between these two diseases is that osteomalacia is easily treated with vitamin D supplements.
Common food sources of vitamin-D include Fish liver oil, sardines, tuna, salmon, liver, and eggs. Vitamin D is also available in its supplement or food form, as vitamin D-2, called ergocalciferol, and as vitamin D-3, or cholecalciferol. Ultra violet rays acting directly upon the skin can synthesis vitamin D, so exposure to sunlight 2 to 4 times per week is usually an effective way to for assure adequate levels of Vitamin D. This process can be limited for those who live in high-smog areas, who wear sun blocking agents, or by those with naturally dark or tanned skin.
The current Recommended Daily Allowance of Vitamin-D is 400 iu, or international units per day. Common current supplemental doses of Vitamin D range from 400 to 1,000 iu per day, and are extremely safe at this level.
High levels of vitamin D can be toxic. Children begin to show toxic effects when dosages exceed 1,800 iu per day. Adults can show toxic effects with dosages ranging from 10,000 to 20,000 iu per day over extended periods. Symptoms of vitamin D toxicity can include weakness, loss of appetite, unusual thirst, nausea, vomiting, high blood pressure, and elevated calcium levels in the blood. Toxic effects are easily corrected by simply cutting back on the daily intake of vitamin-D. Prolonged exposure to sunlight, while unsafe for other reasons, cannot lead to vitamin D toxicity.
VITAMIN D AS AN ADJUVANT FOR CANCER TREATMENT: There is increasing evidence that vitamin D and its analogs help to prevent and treat several forms of cancer. In a study in the Feb 1994 issue of Research Communications in Chemical Pathology and Pharmacology, vitamin D-3 analogs were less toxic and more effective than fish oil derived vitamin D in normalizing malignant Iymphoma and leukemia cell lines. In the April 1, 1994 issue of Cancer Research, vitamin D analogs effectively prevented and treated breast cancer in rats, significantly enhancing the ability of tamoxifen to render the rats tumor free by the end of the experiment. In the Feb 1994 issue of Leukemia, vitamin D-3 significantly enhanced the effect of Bryostatin 5 in treating human leukemia cell lines. In the Feb. 1994 issue of Pathologie Biologie, vitamin D analogs were shown to be important in regulating the immune system by enhancing immune function against cancer cells and infectious agents, and by preventing autoimmune diseases such as lupus and diabetes.
In a study from The Netherlands in the Feb 1994 issue of Breast Cancer Research and Development, relatively low doses of vitamin D analogs combined with tamoxifen produced “potent inhibition of breast cancer cell proliferation…and indicated a benefit of combining these agents as a treatment for breast cancer.”
Some of these vitamin D analogs are available in Europe and are slowly being accepted by oncologists in the United States as effective adjuvants to conventional cancer therapy. The advantage of using vitamin D analogs is that they do not cause the body to absorb too much calcium, which is one of the toxic effects of ingesting too much vitamin D. For breast and prostate cancer patients, researchers often suggest adding about 3,000 IU of vitamin D-3 based upon the latest findings.
Vitamin E is composed of a group of eight compounds (four tocopherols and four tocotrienols) that were first discovered in the 1920s. Alpha tocopherol is the most potent and most commonly used form of this fat-soluble nutrient.
Vitamin E functions as a powerful antioxidant to protect human cells and fatty tissues from free radical damage. Free radicals are extremely dangerous and reactive oxygen compounds that are constantly being produced from a variety of natural sources such as radiation, air pollution, and the breakdown of proteins in the body. Left unchecked, free radicals course throughout the body, rupturing cell membranes, causing massive damage to skin and connective tissues, and damage cellular DNA which gives rise to various cancers and degenerative diseases. Free radical damage also accumulates in the brain, leading to age-related memory impairment.
Vitamin E, in combination with other antioxidants, works to quench free radicals and prevent oxidation of polyunsaturated fatty acids that make up cell membranes. By neutralizing free radicals and stabilizing fatty cell membranes, vitamin E helps to prevent cancer, arthritis, immune disorders such as lupus, and premature aging. Working with vitamin A and beta carotene, vitamin E protects the lungs from air pollution. Vitamin E also protects the cells lining blood vessels walls from free radical damage, thus preventing atherosclerosis and cardiovascular disease. By protecting red blood cells from damage, vitamin E also prevents a special form of anemia called hemolytic anemia.
Vitamin E also plays an important role in the production of prostaglandins, vital hormone-like substances that regulate blood pressure, reproduction, and muscle contractions. By acting as a antithrombin agent vitamin E can help prevent heart attacks by controlling the formation of potentially fatal blood clots. Vitamin E is also used in the treatment of fibrocystic breasts and premenstrual syndrome, promotes healing while reducing scarring, and prevents the formation of cataracts in the eyes. Recently, researchers reported that men taking vitamin E supplements experience 34% few cases of prostate cancer, and 16% fewer cases of colorectal cancer.
A deficiency of Vitamin E can cause hemolytic anemia in infants, wherein red blood cells are destroyed. Adults rarely experience symptoms of vitamin E deficiency unless afflicted with fat malabsorption syndromes such as cystic fibrosis, sprue and celiac disease. Symptoms are easily treated with alleviated with vitamin E supplementation.
The male sex gland, the testis, is responsible for the production of sperm and the secretion of testosterone. Testosterone, the hormone responsible for sexual desire, is dependent on vitamin E to produce sperm and to provide strong masculine features. The female sex glands, the ovaries, produce estrogen and progesterone. For these hormones to function properly, they require adequate amounts of both vitamin E and niacin.
Two recent studies of vitamin E and its ability to significantly reduce the risk of heart failure clearly show that, at higher levels than can be obtained from vitamin-rich foods, vitamin E supplementation was found to reduce the risk of coronary heart disease by as much as 33% to 50%. The impact of the antioxidant vitamin E on women and men was examined in a pair of studies presented at the annual scientific meeting of the American Heart Association in New Orleans.1
Over 87,000 female nurses between the ages of 34 and 59, who were free of coronary heart disease when the study began in 1980, were followed for 8 years. Of the 17% who took vitamin E supplements at the rate of 100 international units (IU) per day, clear benefit accrued in proportion to how long the regimen continued. In assessing the risks, those who took vitamin E for less than 2 years had a 36% reduction in coronary heart disease, and those who took it for more than 2 years had nearly a 50% reduction in cardiovascular disease.
In the study involving male healthcare workers (more than 45,000 were followed from a disease-free baseline established in 1986), vitamin E supplementation in excess of 100 IU for more than 2 years resulted in a 26% reduction in CHD. Meir Stampfer, MD, an investigator in both studies, was amazed by the results, even though he knew that there was a sound scientific basis for the antioxidant hypothesis. This mechanism holds that the “bad” LDL cholesterol is oxidized when not protected, which makes it rancid and thus susceptible to promoting the buildup of fatty lesions on the walls of arteries. Called atherosclerosis, this accumulation is responsible for diminished blood flow and, if allowed to continue, eventual heart attack. Vitamin E is thought to help prevent the oxidation that initiates this disease. 1. Weeks J Lewis Hl.. New studies suggest vitamin E reduces heart disease risk in men and women (abstracts 1847 1848).Amercan Heart Association News Release. November 17, 1992.
Recent studies suggest that as an active blood lipid antioxidant, vitamin E can go a long way toward reducing the risk of atherosclerosis. Atherosclerotic plaque, which congests arteries and contributes to heart attacks and strokes, is thought to be caused by LDL cholesterol altered through the process of free-radical auto-oxidation. The immune system’s macrophages gobble up the oxidized LDLs and expand to form unrecognizable “foam” cells which adhere to artery walls and initiate atherosclerotic plaque. One recent study conducted at the University of Texas demonstrated considerably reduced oxidative damage (over 50%) in the blood of men given 800 IU of vitamin E per day for 12 weeks. 1
An Austrian study of shorter duration found a similar effect when levels of vitamin E up to 1,200 IU were given.2 Additionally, the same study showed that the total level of antioxidants, rather than vitamin E alone, had a higher correspondence with the inhibitory effects. Other studies since published have continued to establish the free-radical auto-oxidation of LDL and heart-disease relationship.3,4
FOOTNOTES 1. Jialal 1, Crundy SM. Effect of dietary supplementation with alpha-tocopherol on the oxidative modification of low density lipoprotein. J Lipid Res. 1992;33:899-906. 2. Dieber-Rotheneder M, Puhl H, Waeg G, Striegl G, Esterbauer H. Effect of oral supplementation with D-alpha-tocopherol on the vitamin E content of human low density lipoproteins and resistance to oxidation. J Lipid Res. 1991;32:1325-1332. 3. Steinberg D. Antioxidants in the prevention of human atherosclerosis. Summary of the proceedings of a National Heart, Lung, and Blood Institute Workshop: September 5-6, 1991, Bethesda, Maryland. Circulation. 1992;85:2337-2344 4. Regnstrom J, Nilsson J, Tornvall P, Landou C, Hamsten A. Susceptibility to low-density lipoprotein oxidation and coronary atherosclerosis in man. Lancet. 1992;339:1183-1186.)
VITAMIN E AND ACUTE PHASE RESPONSE: Vitamin E researchers Mohsen and Simin Nikbin Meydani, working at Tufts University’s Department of Agriculture’s Human Nutrition Research Center on Aging, have shown that vitamin E may be able to reduce the damage to muscles caused by rigorous excercise. (1, 2) Certain athletes and especially long-distance runners have the need to inhibit and limit the kind of muscle damage that would cause them to fall and (perhaps) not to rise to the occasion of their next sporting event. In a double-blind, placebo-controlled study, 21 males, representing two ranges of age (22-29 and 55-74 yr), took 800 IU/day of vitamin E supplements and, for 48 days, ran downhill on an inclined treadmill to accentuate damaging eccentric muscular contractions .
It had been thought that several host defense responses and metabolic reactions that occur during infection also occur after exercise. These reactions, known as the “acute phase response,” contribute to the breakdown and clearance of damaged tissue after exercise. When the subjects were monitored and examined for 12 days, the deleterious effects of exercise related changes were reduced in those taking vitamin E and the age-related differences were eliminated by increasing the response mechanisms of the older group.
1. Cannon JG, Orencole S et al. ATn J Physiol Dec 1990, 259 (6 Pt 2),pR1214-9. 2. 2. Cannon JG, Meydani SN, et a!. Am J Physl Jun 1991, i60 (6 Pt 2), pR1235-40)
The Daily Recommended Intake for vitamin E is 30 iu or international units, though commonly, daily doses range from 200 to 1200 iu.
Foods high in vitamin E include wheat germ, whole grains, cold-pressed vegetable oils, nuts and seeds, dark green leafy vegetables, eggs, sweet potatoes, brussels sprouts and whole wheat. Vitamin E supplements are available in both dry form and oil capsules. Vitamin E is also available in the natural or D-alpha-tocopherol form, and as a synthetic or DL-alpha-tocopherol form.
Vitamin K, also called Menadione, is an essential fat-soluble vitamin that is required for the regulation of normal blood clotting functions. Dietary vitamin K is found primarily in the form of dark leafy vegetables, but most of our needs for this micronutrient are met by microorganisms that synthesize vitamin k in our intestinal tract. Vitamin K’s main function is in the synthesize of prothrombin, a protein vital for blood clotting. Vitamin K also aids in converting glucose into glycogen for storage in the liver, and may also play a role in forming bone formation and preventing osteoporosis. Cancer researchers are also looking into vitamin K’s potential to inhibit development of cancers of the breast, ovary, kidney, colon, stomach, bladder, and liver.
Vitamin K deficiency is rare except in the case of newborn infants. Most vitamin K is synthesized by microorganisms in our intestines. It can take several weeks for this bacteria to get established in newborns, so injections are generally given to the newborns immediately after birth. Vitamin K is often included in prenatal supplements for expecting mothers.
Vitamin K deficiency, though relatively uncommon in adults, can result in impaired blood clotting and internal bleeding. A deficiency of vitamin K can be caused by chronic use of antibiotics which can inhibit the growth of the intestinal microorganisms required for the synthesis of vitamin K. Serious liver disorders can also inhibit vitamin K’s function in the production of prothrombin, and any condition or syndrome that inhibits the digestion and absorption of fats in the intestines can also lead to deficiency symptoms.
The 1989 RDAs for vitamin K is 5 micrograms for newborn babies, and between 65 and 80 micrograms for adults. Vitamin K supplements are only available by prescription due to the danger of toxicity. Foods high in natural Vitamin K include alfalfa, broccoli, dark green leafy vegetables, and soybeans, blackstrap molasses, egg yolks, oats, liver, cheese, and wheat.