The word vitamin is imbued with almost miraculous, mystical qualities. Can there be anything wrong with something if it is called a vitamin? Further, if a little is necessary and good for you, then lots of it must be great. It makes sense doesn’t it?
The history and discovery of vitamins is an extraordinary example of medical science at its best. An English physician in the 1700s was the first to suspect that scurvy, a bleeding and eventually fatal disease of the gums and blood vessels, was caused by a lack of certain substances in food. Scurvy commonly developed in sailors on long voyages. In an experiment, he gave half the sailors lemons and the other half none. None of the lemon sailors got scurvy while the others did. Over the years, one by one, vitamins were discovered. Each was found to have an important role in health. Each in very small amounts prevented a deficiency disease such as beriberi, rickets, pellagra and anemia. It was really quite an accomplishment and science did it. So, vitamins are necessary to prevent deficiency diseases.
Keep in mind that a vitamin is simply a substance that works inside the body’s cells to keep our physiology functioning normally. There is nothing magic or saintly about vitamins. They are like motor oil which is required for a smoothly running car engine. At present in America, except for vitamin D which is fairly common, there are so very few instances of any vitamin deficiencies that many physicians can go through their entire career without seeing a single one.
We have been taught that taking vitamins, like brushing our teeth, is a necessary part of living. Yet, a federal research study of 11,000 Americans in 1993 found that ordinary vitamin takers as a group did not live longer or have fewer cancers than non-vitamin takers. Of interest is the fact that these vitamin takers generally are a healthier group as they tend to be non-smokers, eat healthier foods and have less blood pressure and heart problems.
How Are Vitamins Made?
Almost all vitamins are made synthetically in a factory somewhere. The only exception is vitamin B12 which is made “naturally” by bacteria – biosynthesized. When these other vitamins are synthesized, they end up equally in two forms that are mirror images of each other – one is a d (dextra or right) and the other an l (levo or left) form. Only the l form is active in the body. The d form, the mirror image, does not have vitamin activity. These d forms, however, may be active in other ways in the body. In large amounts, they may have harmful effects such as increasing a nasty substance called pteroyl-glutamine acid in the body. Taking mega doses of any vitamin will give your body a very large dose of this inactive d form of whatever vitamin you take.
Types of Vitamins
There are two major categories of vitamins, water soluble and fat soluble.
Water Soluble Vitamins include:
- Vitamin B1 (thiamine)
- Vitamin B2 (niacin, nicotinic acid)
- Vitamin B6 (pyridoxine)
- Vitamin B12
- Vitamin C (ascorbic acid)
- Folic acid (folate)
Water soluble vitamins, when taken in an excessive amount, simply and immediately are excreted in the urine. It is not a vulgarity to say that those who take megadoses of the water soluble vitamins are usually peeing their money down the toilet.
Fat Soluble Vitamins are another matter. These include:
- Vitamin A
- Beta carotene (forerunner of Vitamin A)
- Vitamin D
- Vitamin E
- Vitamin K
Except for beta carotene, if excessive doses of the fat soluble vitamins are ingested, they are stored in body fat and slowly released causing very high blood levels. Large doses of fat soluble vitamins are to be avoided as serious, even fatal, poisoning can occur.
But Everyone Talks of Megavitamins
It is true. There is a great deal of talk about megavitamins. If a little is good, a lot must be better. Some athletes swear by megavitamins. Fitness and health magazines tout them. But what does science and the medical field say? Simply that you urinate out over 95% of the excessive water soluble vitamins and you poison yourself if you take excessive fat soluble vitamins. There may be the exception with vitamin C and vitamin E (see below). What is not in doubt is that if you get vitamins from food or take a small dose of a vitamin, you are getting the normal physiology requirement. If, on the other hand, you take a large dose of a vitamin, you are now taking a pharmacologic dose. This means you are getting a drug effect on the body. A perfect example is niacin. You require only 15-19 mg a day to prevent the disease, pellagra. However, some people take huge doses up to 1500 mg a day to lower their cholesterol. Now we are talking drugs and this dose is very close to the toxic, even fatal dose of 2000 mg a day. Without medical advice, are you really smart to take a vitamin with drug-like effects to lower your cholesterol, when your physician has far more effective and safer drugs with fewer side effects? So much for megavitamins.
The word antioxidant is held up as another miracle to be taken as a supplement. These are put in a variety of cocktails, pills, green tea, soup and even shampoo. They are said to cure arthritis, restore youth, increase the sex drive and provide hundreds of other benefits; a real all-purpose miracle in a bottle or pill.
The Real Miracle Inside
Just what does the word, antioxidant, mean? Oxygen is a gas in the air we breathe. It is needed to create energy in just about every cell in the body. Without oxygen, cells die rather quickly. Oxidation means the chemical change produced by oxygen as energy is created from the food we eat. At the end of these reactions, oxygen combines with hydrogen to form H2O (water). However, in between, as energy is being created, some nasty chemicals are made that can cause damage to cells. These are called free radicals. They don’t stay around very long as the body has its own natural antioxidants which quickly change these free radicals to H2O. So, an antioxidant is simply a chemical that binds these free radicals, rendering them harmless.
Free Radicals – The Bad Guys
Free radicals are constantly being produced as our body metabolizes the energy-rich food we eat. There are literally thousands of these tiny insults occurring within each cell each day. If our body did not normally and instantly neutralize these free radicals, we could not survive. The genetic material within cells would be severely damaged. There is no way to avoid free radicals from occurring within the body. However, there are many things outside the body that increase free radicals. The list includes:
- Cigarette smoke – the worst
- Excessive sun – ultraviolet light
- Excessive medical radiation
- Certain air pollution – nitrogen dioxide and ozone
- Severe illnesses and injuries
- Excessive alcohol
There is a constant battle going on in the body – free radicals normally being produced and many naturally occurring chemicals and enzymes, the body’s own antioxidants, getting rid of them. The above listed substances shift the equation to the bad side and can potentially defeat the body’s defenses. The question is whether taking antioxidant supplements can shift the equation favorably and keep these bad free radicals under control.
Antioxidants – The Good Guys (Mostly)
So the body has many clever chemicals inside that control free radicals. What is now known is that antioxidants also do occur naturally in many of the foods we eat. They are present primarily in plant food. These are called phytochemicals, meaning chemicals that come from plants. In particular, the large family of carotenoids found in dark green, yellow and orange vegetables and fruits contain literally hundreds of very active antioxidants. There are now many medical studies that show that the risk of cancer, heart disease and even cataracts is greatly reduced when a person eats a diet high in fruits and vegetables.
Vitamin C is an antioxidant. It is easy to get lots of vitamin C in citrus juices and many vegetables. The evidence for taking vitamin C supplements is mixed. Some experts say that it may be helpful. Most others say there is no medically proven benefit. All the experts say a person should not take megadoses of vitamin C. That means over 500 mg a day.
Vitamin E is an antioxidant. It is very hard to get a significant amount of this vitamin in the diet as it is present in calorie-rich nuts and vegetables oils. It is about the only antioxidant supplement that has been medically shown to have protective benefits for heart disease and, perhaps, cataracts, Parkinson’s disease and prostate cancer. 200-800 units a day of the mixed tocopherols are recommended.
Selenium is a mineral that has antioxidant activity in the test tube. We generally get enough selenium from the grains we eat. Whether it has any benefit as a supplement has never been proven. You can poison yourself with too much selenium. So if you are determined to take selenium, get your physician to measure it in your blood first. If it is within the normal range, you don’t need selenium.
Enzymes are proteins within cells that promote many necessary chemical reactions. The body has thousands of naturally occurring enzymes, some of which are antioxidants that get rid of free radicals. However, any protein, including enzymes taken by mouth, is quickly destroyed by stomach acid. So, an enzyme supplement taken by mouth likely is completely inactivated by stomach acid.
The Bottom Line
Antioxidants are part of the body’s normal metabolism. These substances operate smoothly to keep us healthy if we give the body a chance. We do that by avoiding the major negative factors such as tobacco smoke, pollution and excessive sun. We add to our own antioxidants by eating the right foods – meaning substantial quantities of fruits and vegetables every day. Vitamin E and Vitamin C may be helpful but are not clearly proven. All of the other antioxidant supplements are unproven and may actually be hazardous.
The B Vitamins
We can discuss the B vitamins as a group although each has its own deficiency disease which most doctors in the U.S. never see as they are now very uncommon.
|B1 – Thiamine||beriberi – brain, nerves, heart|
|B2 – Niacin||pellagra – skin|
|B6 – Pyridoxine||brain – blood – heart|
Thiamine is present in grains, pasta, cereals and many other plant foods. The only people who are ever deficient are those too poor to have a diet containing these foods or the severe alcoholic, particularly the binge drinker, who may eat poorly.
Niacin is present in liver, yeast, bran and legumes. Deficiency in developed countries is almost unknown. Some people on their own take large doses of niacin to reduce cholesterol. You may need to take up to 1500 mg a day which causes nasty stinging and flushing in the skin. It is also close to the maximum recommended dose of 2000 mg a day. If you have a cholesterol problem, there are excellent prescription medicines available with few side effects. See your physician.
Pyridoxine (Vitamin B6) is available in meat, whole grains, soybeans and vegetables. Deficiency is very uncommon. A supplement is needed when taking certain tuberculosis medications. It is uncertain what megadoses do in the body. A small amount in a multivitamin or B complex tablet is okay.
Vitamin B12 is present in meats, fish, poultry and eggs but not in plant food. A strict vegetarian could become deficient although many vegetarian products such as soy milk are now fortified with B12. Up to 30% of Americans over the age of 60 may no longer be able to absorb vitamin B12. A multivitamin or B complex tablet containing about 3 mg a day is recommended. Be sure that folic acid is also present in multiple vitamin preparations.
In summary, B vitamin deficiency is almost unknown in America. Many people take a B complex vitamin with folic acid, just to be sure. Women of childbearing age should get 400 mg of folic acid a day.
Homocysteine, Folic Acid, the B Vitamins and Heart Disease
There is a human gene that regulates a substance in the blood called homocysteine. High blood levels of this substance seem to damage the inside lining of arteries leading to cholesterol buildup and heart attacks. This may explain why some people with normal or even low cholesterol levels have heart attacks. In medical studies it appears that people who are deficient in this gene with a resultant high homocysteine level and who take inadequate amounts of vitamin B6, B12 and folic acid, have higher heart attack rates than those who take supplements of these vitamins. This problem is not present in the majority of the population who do not have this buildup of homocysteine. For women in particular, check the dosage to be sure you are taking 3 mg of vitamin B6 (pyridoxine) and 400 micrograms (0.4 mg) of folate or folic aid as these seem to be protective and prevent certain malformations in a developing fetus.
Folic Acid (Folate) is necessary for normal protein metabolism and red blood cells. It helps break down high blood homocysteine. It has now been clearly shown that deficiency of this vitamin in the pregnant female can result in severe birth defects in the fetus. The food industry now fortifies many of our ordinary foods such as breads and cereals with folic acid. However, even this amount may not be enough for childbearing females. The present recommendation is present in most multivitamin preparations. Read the label to see if this amount is in each pill. Also, be sure there is at least 1 mg of vitamin B12. Megadoses of folic acid produce no benefit and may cause a crippling disorder in people who also have a deficiency of vitamin B12.
Vitamin C – It was the Nobel Prize-winning scientist Linus Pauling who felt that megadoses of vitamin C could prevent the common cold and, since it is an antioxidant, prevent the aging process. Indeed, he did live to be 90, but so do many other people. Vitamin C is needed to heal cuts, absorb iron from the intestine and maintain the health of arteries. The evidence for prevention of the common cold is mixed at best. (See section on Zinc, under Minerals, on how to really prevent common colds). The minimum dose required for vitamin C is 60-200 mg a day. If you take much more than 50 mg a day, it is mostly excreted in the urine.
Megadoses of vitamin C may cause kidney stones, interfere with some medications such as anticoagulants and increase iron absorption in people who have the common bad gene for a disease called hemochromatosis which results in iron damage to the heart and liver. Remember, when you take a megadose of any vitamin, you are no longer taking a vitamin but rather an untested drug. The medical experts can’t agree on whether a supplement is beneficial or not. Up to 500 mg of vitamin C a day as a supplement is probably safe.
Vitamin A is a fat soluble vitamin necessary for healthy skin and bones. It is hard not to get adequate vitamin A in the diet. Carotenoids are the forerunner of beta carotene which, in turn, is converted into vitamin A in the body. These healthy substances are present in many fruits, vegetables, egg yolks and dairy products. So, you really don’t need to take any vitamin A supplement.
It is possible to poison yourself, even fatally. Arctic hunters who have eaten polar bear liver, which contains enormous amounts of vitamin A, have died of acute vitamin A poisoning. So have children who get their hands on a bottle of vitamin A tablets. Pregnant females who take these supplements risk birth defects in their fetus; 800-1000 micrograms (equivalent to about 3000 IU) are all you need each day. Trust your diet on this one.
Beta Carotene – This nutrient, found widely in plants, is converted into vitamin A in the body. In the laboratory, it is an antioxidant. For years and without solid evidence, it has been promoted as a health benefits in cancer and heart disease prevention. Beta carotene is not strictly a vitamin but rather a carotenoid. Unlike vitamin A, it apparently can be taken in large amounts. Beta carotene is present in many vegetables and fruits. The short list of foods high in carotenoids are carrots, oranges, tomatoes, red grapefruit, broccoli, Brussels sprouts, leafy green vegetables, sweet red peppers and many other fruits and vegetables. There are about 600 naturally occurring different carotenoids and only 400 of them have even been identified. These are all antioxidants. As such, they were given center stage as candidates for preventing cancer, heart disease and aging.
But, there may be some problems with taking beta carotene supplements. In fact, smokers who take the supplement seem to have an increased risk of lung cancer. As we are learning, it is extremely hard, perhaps impossible, to take one specific nutrient with the idea that it can induce one or two specific health benefits. It is far more likely that the hundreds of carotenoids in the healthy foods we eat act in concert to produce overall good health, reduce cancer and heart disease and perhaps increase life expectancy. The experts now agree that beta carotene supplements should not be taken.
Vitamin D exerts its beneficial effect by increasing the intestinal absorption of calcium that is needed for building strong bones and teeth. It is present in meat, fish and fortified milk. Medical studies do show that people who supplement their diet with vitamin D and calcium have less bone loss with aging and fewer fractures.
It has been found that there are attachment points (receptors) for vitamin D in many other organs of the body than the intestines and bones. These have been found in the brain, for instance. So, vitamin D may have many other beneficial effects in the body. Additionally, vitamin D deficiency has been found to be very common in the U.S. Because of these factors, the recommended daily dose of vitamin D has been increased from 400 IU to 800-1200 IU per day.
Vitamin D is also made in the skin when it is exposed to sunlight. In the white race, as little as 15-20 minutes a day in the sun creates enough vitamin D in the skin for the body’s use. The more pigment there is in the skin, the less sunlight gets through so that deeply pigmented and black individuals create little vitamin D. A quart of vitamin D fortified milk a day is enough. The previous recommended dose was 400 IU a day. Because of widespread deficiency of this vitamin D, 800-1200 IU are being recommended by most experts. Check your sunlight exposure, your milk intake and the amount of vitamin D in your multivitamin preparation.
Vitamin E is one antioxidant that may measure up to some of the hype. Vitamin E has been promoted as just about the best thing to take for just about every ill of mankind. In the last decade, credible researchers have begun to unravel the fact from the fiction.
Vitamin E refers to a group of substances called tocopherols. These include alpha, beta, gamma and delta tocopherols. The alpha type is by far the most common in the body and in supplements. Some supplements do contain small amounts of the apparently much more potent gamma tocopherol. These are called mixed tocopherols. Vitamin E is an antioxidant which helps mop up free oxygen radicals which are substances that seem to cause cell damage. Vitamin E occurs naturally in vegetables oils such as corn, soybean, safflower, sunflower and cottonseed. It is also present in nuts and whole grains. The average American intake is about 17 IU a day. To get more than this requires ingesting a lot of foods high in fats and calories.
In the past, there was ome medical evidence to suggest that vitamin E may help heart disease. Vitamin E supplements are no longer recommended after recent studies, however, suggest they may increase the risk of stroke.
If you are deficient, the recommended dose of vitamin E is no more than 400 IU a day. Try to get the mixed tocopherols. If you take warfarin (Coumadin), check with your physician as your blood may become too thin. In addition, patients with certain types of anemia, intestinal problems and liver conditions should be careful. Some studies suggest that vitamin E supplements may help a particular liver problem called fatty liver disease. The benefit of this therapy, however, must be weighed aganst the potential side effects. Consult with your doctor.
Vitamin K is necessary for proper coagulation of the blood. It is present in many vegetables, especially green leafy ones. It is also made by the bacteria in the large intestine. It is hard to avoid vitamin K. A deficiency of the vitamin is almost unheard of in the U.S. Its importance may be for those people who take a blood thinner called warfarin or Coumadin. Warfarin interferes with the production of a substance in the liver called prothrombin. Vitamin K is required in small amounts to form prothrombin. If a patient who is well-regulated on warfarin were to suddenly eat excessive amounts of vegetables containing vitamin K, the measured prothrombin time and effectiveness of the medication could drop. There is no need for vitamin K supplements.