Caution Megavitamins May Be Dangerous To Your Health

Caution: Megavitamins May Be Dangerous To Your Health by Dr. Alan Immerman, D.C.

Surprising as it may sound, vitamins—especially the fat-soluble ones—when taken in unnaturally large quantities, can be dangerous to your health. In fact, megavitamin therapy carries risks similar to those of other drugs. Just as with other medications, the taking of large amounts of vitamins can cause side effects and other more serious health problems.

For years I took large daily doses of many vitamins. I read many of the magazines which are sold in health food stores and I believed what I read. I was convinced that large doses of vitamin C would “prevent” and “cure” colds and that some of the B-complex vitamins would calm my emotions “naturally” with no side effects. I believed that large amounts of vitamin E would prevent heart disease and delay the aging process. Fortified daily as I was, I was certain that I was doing myself a world of good, even though I didn’t feel better while I was taking the supplements in such large doses.

Then it happened: I put down my health food store paperbacks long enough to read a few scientific textbooks and journal articles. I studied the biochemistry of vitamins (I have a B.S. in chemistry) and I read scientific studies which investigated the possibility of side effects from taking vitamins. I was more than a little surprised by what 1 found.

First, what is a “megavitamin”? I consider it to be a level of dosage that one could never get from food. For example, if you ate a large amount of fruits and vegetables, you could get 500 to 1,000 milligrams (.5 to 1 gram) of vitamin C per day from food. Although the RDA (recommended dietary allowance) is only 60 milligrams, it is possible to get ten, even 20 times this amount from foods. Therefore, in the case of vitamin C, I would use the term megavitamin to describe something in the neighborhood of 2 grams per day. While this may seem extraordinarily large, bear in mind that some self-appointed authorities recommend that we take 5-10 grams of vitamin C per day.

In large doses, vitamins act like drugs, not nutrients. If you eat more than the amount required, your body won’t be able to use them. In its wisdom, the body will try to eliminate the excess, but too much of an overload may cause the excess to remain in the bloodstream, causing drug-like effects.

Megavitamin proponents argue that the requirement for vitamins differs from one person to another (biochemical individuality). This is true. But the conclusion that some people must, therefore, take megadoses of vitamins is false. Taking the recommended dietary allowances of vitamins fulfills the body’s needs since the RDAs have been formulated with full awareness of biochemical individuality. The RDA compensates so well for the fact that some people need more of a certain vitamin that it has even been occasionally criticized for being too generous, for instance in the RDA for vitamin E.

Megavitamin proponents claim that large amounts of vitamins are used as nutrients. A nutrient is a substance that is used in normal physiological processes and causes no harm to the system. Other chemicals, such as drugs, are not used by the body and do cause harm. Scientific studies have shown that megavitamins can cause harm to the body. Therefore, I classify them as drugs.

Our bodies are capable of using nutrients supplied in the proper amounts. But when a nutrient is supplied in too great an amount, havoc is the result. We have all heard of the rare cases where someone has drunk too much water and died. The same is true with vitamins: too much of a good thing is harmful.

Experiments such as the following have often been repeated. Megadoses of vitamin B3 (niacin) were given to large groups of experimentees for a number of weeks at a time. Before and after the dosage period, blood was drawn from the subjects and analyzed for many chemicals. At the end of the experiment, scientists found that up to 45% of the subjects had liver damage, 50-66% had abnormally high levels of blood sugar, 62-78% had unsafe levels of uric acid and 20-40% had “gastrointestinal distress” (stomachaches). Though it may be hard to swallow that our old friend niacin is harmful in large doses, swallow it we must if we want to align our beliefs with reality.

Niacin has been recommended in large doses to lower blood cholesterol levels and to control schizophrenic symptoms. I suggest that better ways be found to deal with these problems (such as eating less meat and eggs to lower cholesterol).

Megadoses of vitamin C are also potentially harmful. Consider the following side effects: destruction of red blood cells; irritation of the intestinal lining; kidney stone formation; interference with iron, copper, vitamin A and bone mineral metabolism; interference with the reproductive tract, causing infertility and fetal death; diabetes; and something called rebound scurvy. Scurvy is vitamin C deficiency disease. If you take large amounts of vitamin C for a long time (many months, at the least), your body will increase its level of elimination of vitamin C (more evidence that your body doesn’t want it around). If you then decide suddenly to stop taking vitamin C cold-turkey you will become deficient in this vitamin because it takes a period of time (many weeks sometimes) for your body to adjust downward its level of elimination of vitamin C. Does this sound safe? I would rather have a cold any day than the possibility of the side effects of megadoses of vitamin C. Besides, a cold is actually a detoxification process that shouldn’t be interfered with by use of anything, even  it is a supposedly friendly vitamin.

The third vitamin that has been investigated in depth is vitamin E. Megadoses of this vitamin (over about 100 IU per day) have been found to cause deposits of cholesterol in blood vessels; elevations of blood fat levels; interference with the bloodclotting process; enhanced growth of lung tumors; interference with absorption of vitamin A and iron; gastrointestinal disturbances; skin rashes; interference with thyroid gland function; and damage to muscles. Thus, megadoses of vitamin E also function as drugs, complete with side effects.

All nutritionists recognize the hazards from large doses of vitamins A and D: Megadoses of vitamin A have been known to cause the following negative effects: fatigue; generalized feeling of sickness; stomach discomfort; bone and/or joint pain; severe headaches; insomnia and restlessness; night sweating; loss of body hair; brittle nails; constipation; irregular menstruation; emotional instability; dry scaly and rough skin and other effects. Megadoses of vitamin D can cause nausea, diarrhea, weight loss, kidney damage and other problems.

I have no argument with those who claim that megadoses of vitamins will change the way you feel. They may, although in most cases there is no solid scientific proof that they will. But the way you feel is not in itself a valid criteria with which to judge megavitamins. If it were, then we could endorse drugs as completely beneficial. Both drugs and megavitamins may change symptom patterns. If you take vitamin C, there is a slim chance that you may experience a reduction in cold symptoms due to an antihistamine (not nutritional) effect. If you have arthritis arid take cortisone, you will experience a reduction in joint pain. But both these substances have side effects; and neither of these substances are getting at the cause of the health problem, just the symptoms. In fact, both are causes of other problems!

And there is even more: By treating yourself with vitamins, you may mask a serious disease until it has progressed to the point of no return. For instance, if you are anemic from vitamin B12 deficiency and you take folic acid, the folic acid will correct the anemia but you will have continuing subtle nervous system damage from the B12 deficiency.

Megadoses of vitamin C interfere with tests for sugar in the urine (a common indicator of severity of diabetes) and for blood in the stool (a test for cancer of the large intestine, among other things).

Once you find out what your problem is, I have one bit of advice: Don’t try megavitamins for a solution. If they give you any relief, it will only be symptomatic: the cause of your problem will remain untouched. And the megavitamins may cause even further disruption of your health because of the many harmful side effects they can have.