MEGASCORBATE THERAPIES: Vitamin C in Medicine: Vol 2, 1

"THE JOURNAL IS UNDER CONSTRUCTION: This page last revised 12-17-1999

Copyright (c) 1997 "The Vitamin C Foundation "




ascorbic acid - a water soluble vitamin, C6H8O6, occurring in citrus fruits, green vegetables, etc., essential for normal metabolism: used in the prevention and treatment of scurvy: Also called vitamin C
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VITAMIN A TOXICITY A MEDICAL ERRONEOUS ZONE


A Personal Opinion by
Donald R. Davis, Ph.D.*

From the International College of Applied Nutrition Update, October 1983




Early this year [1983]a monthly newsletter of medical information for the public discussed a recent case of vitamin A toxicity. The brief story told of a young woman who had visited her doctor due to dryness of her eyes, sore tongue and gums, cracking at the corners of her mouth, a constant I headache, and persistent nausea. She had given up jogging due to severe pain in her bones. All symptoms were consistent with a diagnosis of hypervitaminosis A. The newsletter went on to say that she was a health food store employee who admitted taking 25,000 international units I (IU) of vitamin A daily for several months. Her liver was disturbed and her blood vitamin A level was elevated. Hospital treatment with intravenous fluids had normalized her blood levels of vitamin A in about a week, the story concluded, but "had she taken vitamin A in excess much longer, early death from liver failure would have become inevitable."

To those familiar with the literature on vitamin A toxicity[2], there are at least three startling statements in this story. Most surprisingly, the reported toxic dose was two-to-six-fold lower than the lowest toxic doses previously reported. In fact, capsules containing 25,000 IU of vitamin A are widely used. Secondly, in previous reports elevated blood levels of vitamin A did not normalize rapidly (although prompt relief of symptoms is often reported). Finally, the unprecedented reference to inevitable early death on such very low dose was alarming.

Further investigation revealed, however, that the original report, did not support any of the startling statements in the newsletter. The woman had actually reported taking 25,000 IU twice daily for long time periods, plus an additional 50,000 IU of vitamin A (a total of 100,000 IU per day) for one week prior to her visit to the physician. Her blood levels of vitamin A were measured only twice, both near the, time she was first seen, at which time they were far from normalized. The intravenous fluids actually were given to reduce her elevated serum calcium level (14.4 mg/dl) not her vitamin A level. It was her serum calcium level (the featured topic of this medical report) which normalized rapidly. There was no mention of inevitable early death- The woman was described as "moderately ill and weak," and her symptoms disappeared within two to ten days.

Exaggerated, emotional and simply erroneous statements about vitamin A toxicity are surprisingly common. It seems that for many physicians and others, one of the serious side effects of even thinking about vitamin A toxicity is that it stimulates excessive emotion and imagination and causes a striking loss of perspective and scholarly standards. The editors and review boards of reputable publications seem to be among the high risk groups. Also, there is a tendency for this side effect to be progressive -- stories about vitamin A toxicity tend to become more grave and unbalanced with each retelling.

It seems to be common "knowledge" that vitamin A supplements and polar bear liver have killed many people. The medical article cited above says that deaths have occurred "on occasion," and cites two references for this statement. However, no deaths are mentioned in either reference. A letter from one author of the article graciously acknowledged these errors of citation, but stated that "clearly" deaths have been reported since the time of the original polar explorations. Significantly, he gave no references.

Polar bear liver is well known to sometimes cause brief toxicity, but apparently without fatality.[4] Vitamin A supplements have been used-and sometimes abused-for nearly half a century, but there seems to be only one fatality recorded in the English language.[6],[9] He was Basil R. Brown, Ph.D., a 48-year old chemist in England. Convinced that carrot juice or vitamin A supplements would help his various minor ailments, he took large doses over a 6-year period prior to his death. Despite medical warnings and serious illness, he took up to a gallon of carrot juice daily and an estimated average of over two million IU daily of retinyl acetate during one 3-month period. His cause of death was stated to be liver cirrhosis, accompanied by severe jaundice and liver enlargement.

Possibly no other health hazard is cited so frequently but occurs so rarely. Only about five cases of toxicity are reported annually in the United States.[2] No doubt there are additional unreported cases, but the same must be said for a multitude of other rare toxicities which (though less publicized) occur far more frequently. In 40 years of vitamin A supplementation there has never been a fatality reported in the United States, while each of the following easily available items has caused death and more frequent disability: peanuts, strawberries, rhubarb, undercooked pork, broad beans (fava beans), and shellfish.-[5],[10]

The sometimes harsh medical criticism of rare vitamin A toxicity seems particularly lacking in perspective. Adverse reactions to medically prescribed drugs cause perhaps 5% of all hospital admissions and tens of thousands of deaths yearly,[7] a million times the death rate from vitamin A toxicity. Even "safe" aspirin causes nearly 100 deaths annually.[8] What would be the medical outcry if vitamin A caused one-tenth of the mortality of aspirin?

Even among nutrients, the lethal reputation of vitamin A is quite out of proportion to reality. Vitamin D has caused perhaps about one death per year, while innocuous-sounding iron supplements top this brief list with a few deaths per year in children. It seems unfortunate, but true, that the attention given to vitamin A toxicity cannot be explained on the basis of strictly humanitarian concerns.

Why is the medical emphasis on vitamin A toxicity so very disproportionate? The major reason may be that vitamin A, more so than vitamin D or iron, for example, has been the object of widespread popular interest that infringes on territory which many physicians and medical scientists feel should be theirs alone. The potential toxicity of vitamin A may provide a convenient cover for seemingly justified expressions of disapproval, not only of vitamin A supplements, but of individuals who are interested in nutritional supplements and nutritionally oriented medicine. If so, we could explain how accuracy, objectivity and perspective become lost, as if they were almost incidental.

This process can snowball. Inaccurate and exaggerated statements, frequently repeated in reputable publications, are accepted and innocently propagated even by those who would not have originated the distortions. Most holders of such myths are unsuspecting of their political aspects and weak factual basis.

Some may rationalize that there is no harm in exaggeration if it might help prevent vitamin toxicity or encourage undue interest in nutritional supplements in general. But there are two kinds of harm which such rationalizations overlook. One is a serious loss of credibility among some people who become convinced that medical warnings about vitamin toxicity are just ignorant or manipulative scare tactics. Many people, for example, take 25,000 IU or more of vitamin A daily (implied by the medical newsletter to cause "inevitable early death") and report only benefits. Unrealistic warnings can be self-defeating, like "crying wolf."

The other kind of harm from overblown warnings is that they feed what for other people is an already exaggerated fear about supplements. The damage done by vitamin A supplements is ridiculously small compared to the plausible damage done by inadequate vitamin A, damage such as birth defects and lowered resistance to infections and cancer. About 20 million Americans have "low or deficient" serum levels of vitamin A," hundreds of thousands times more than all of history's cases of toxicity. Regrettably, the medical profession as a whole has not yet shown a proportionate concern for improving vitamin A intakes among these millions.

The maximum prevention of vitamin A toxicity remains a difficult and complex problem. The complexities include inadequate knowledge of safe levels (which probably vary by at least a factor of ten in various individuals), poor knowledge of the beneficial functions of vitamin A, and the seeming impossibility of preventing a Dr. Brown from harming himself.

We do not even know very well what doses cause toxicity in sensitive individuals. Reports from adult victims range from 50,000 to 600,000 IU daily for periods of six weeks to eight years (average over 200,000 IU/day,)[2] but especially the lowest figures may be underreports. Some embarrassed victims initially have denied taking any vitamin A at all.

Instead of viewing with alarm, and unrealistically calling for medical regulation of vitamin A, physicians could much more usefully start including in every report of toxicity a sensitively done study on whether and how each case might have been realistically avoided. Successful learning about prevention will require that physicians possess a sympathetic, non-judgmental and open-minded attitude, qualities which are presently not always obvious.

Those of us in the blossoming fields of nutrition and nutritionally oriented medicine have a major role to play. Above all we can avoid over-reacting to traditional medical "erroneous zones" in such a way as to encourage anyone to believe that vitamin A toxicity is of no concern. It has caused serious' illness, has led to parathyroid surgery prior to correct diagnosis, and may have caused long-term liver damage. Animal experiments show that vitamin A has the potential to cause birth defects. Physicians using hemodialysis can note a recent report that dialysis patients seem to be sensitive to vitamin A supplements of even 15,000 IU/day, or less. Finally, we can all recognize that "erroneous zones" are a human weakness from which we ourselves may not be immune.

*Clayton Foundation Biochemical Institute, University of Texas, Austin, 78712 and Associate Editor, Journal of Applied Nutrition.

References

  1. Baxi, S.C. and Dailey, G.E. III, "Hyperuitaminosis A: A Cause of Hypercalcemia, " West. J. of Med., 137:429 (1982).
  2. Davis, D.R., "Using Vitamin A Safely," Osteopathic Med., 3:31 (1978). Reprinted in J. lnt. Acad. Preventive Med., 5:38 (1978).
  3. Farrington, K., Miller, P., Varghese, Z., Bailoci, R.A., and Moorhead, J.F., "Vitamin A Toxicity and Hypercokoemic in Chronic Renal Failure," Br. Med. J., 282-1999 (1981).
  4. Halstead, B.W. and Courvdie, D.A., Poisonous and Venomous Marine Animals of the World, Vol. 3, U.S. Government Printing Office, P. 766 (1970).
  5. Jelliffe, E.F.P. and Jelliffe, D.B., Adverse Effects of Food, New York, Plenum Press (1982).
  6. Leitner, Z.A., Moore, T. and Sharman, I.M., Proc. Nutr. Soc., 34:44A (1975).
  7. Mendelsohn, R.S., Confessions of a Medical Heretic, Chicago, Contemporary Books, Inc., p. 26 (1979).
  8. National Clearinghouse for Poison Control Centers Bulletin, U.S. Dept. of Health, Education and Welfare, February 1980, P. 3.
  9. National Inquirer, Lantana Florida, May 5, 1974, p. 26.
  10. National Research Council, Toxicants Occurring Naturally in Foods, Second Edition, Washington, D.C., National Academy of Sciences (1973).
  11. Ten State Nutrition Survey 1968-1970, U.S. Department of Health, Education and Welfare, publication 72-8132, p. IV-135 (1972).
International College of Applied Nutrition Update, October 1983

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