I’ve found a few articles this morning on the dangers of taking high doses – or “Mega” Doses as advertised on over-the-counter “energy shots” – of vitamin B, particularly B-6 which, it turns out, is not water soluble. I’ve also found an article written by a vitamin B-6 proponent who recommends the substance specifically for children with autism.
I am particularly interested in the temporary neuropathy some have reported experiencing on large doses of B-6 because the description exactly describes what seemed to be afflicting me last Thursday after ingesting a product called “Mega Shot” which – although the bottle did not provide the quantity in grams – boasted that it provided “2000%” of daily recommended dosage of B-6, (and “10,000%” of B-12, and “5,000%” of vitamin C… just to give you an idea of the packaging.)
The cases of neuropathy seem to occur over time, which suggests my reaction – if B-6 was indeed the culprit – must be very rare indeed. I admit it’s anecdotal, but I can report that I had never in my previous experience suffered from any numbness in my hands, arms, or feet. Nor am I generally afflicted with circulation difficulties. So, while finding this information does not give me complete vindication – (and I know there’s big money involved, and people trying to sell products; studies and statistics are tweaked by bias on both sides) – it does confirm for me that I should certainly not be ingesting that particular product again.
My opinion in general you already know. All life moves towards its end; we all die, and it really doesn’t matter when, though there is a qualitative assessment connected to the how. Life contains an element of risk which the individual mitigates as he must see fit. I believe that no authority, no government, can be given the power to arbitrate in such matters over the individual without being tyrannical, and I believe that such agencies as do so must be abolished if we are to be free.
Having said that, and acknowledging the caveat emptor which one must apply to everything someone sells him to eat or drink, it is essential to have organizations both for-profit and non-profit which are devoted to supplying us with information so that we may base our decisions in some sort of knowledge.
The first article is from a British nutritional website, BNET Research. I’ve edited the content and highlighted in bold the parts which intrigued me.
The perils of vitamin B6 megadosing
The easy availability of over-the-counter vitamins and the popular view of them as "natural" wonder foods that can ward off disease have made megavitamin therapy widely acceptable. Many Canadians take supplemental vitamins, occasionally in amount 10, 50, even 250 times the recommended daily intake, often without professional advice. Although megavitamin proponents claim benefits for conditions as diverse as wound healing, poor sexual performance, premenstrual discomfort, stress and depression, no firm scientific evidence supports the claims for vitamins overdosing.
Most people don't need vitamin supplements.
In large doses vitamins act as drugs
In megadoses, vitamins are no longer considered to be nutrients but regarded as "pharmacologically active substances" (drugs) that -- like all drugs -- may produce harmful side effects. They can also interact with other medications being taken. In the U.S., all vitamins (except folic acid) are classed as nutrients, with no legal restrictions on the dose or potency of products marketed. But in Canada vitamin preparations are viewed as drugs and must be approved by Health and Welfare Canada's Bureau of Nonprescription Drugs before being offered for sale. When the manufacturer applies for a drug identification number (DIN), Health and Welfare Canada checks the dosage against existing legislation to make sure it's not too high. For example, the upper limit or maximum potency allowed by Canada's Food and Drug Act for an oral dose of vitamin B6 is three mg per pill. No daily dose should exceed it, although authorities cannot control the number of pills someone takes. One expert at the Health Protection Branch of Health and Welfare Canada suggest looking for the "DIN" symbol followed by a six or eight digit number on any vitamin preparation. If the product doesn't bear this mark it is not officially approved and thus cannot be sold legally.
Even water-soluble vitamins can be toxic in megadoses
Whereas the dangers of megadosing with fat-soluble vitamins, especially vitamins A and D, are widely acknowledged, many vitamin advocates assume that any surplus of water-soluble vitamins will be harmlessly flushed out of the body by the kidneys, in urine. However, scientists have now shown that even some water-soluble vitamins can be harmful in large doses. More specifically, research confirms that vitamin B6 can be neurotoxic (nerve-damaging) in amounts over 200 mg a day. Megadoses of other water-soluble vitamins, such as vitamin C, in amounts over one to one and a half grams a day may also damage health. Excessive ingestion of vitamin C can cause diarrhea, increase the risks of oxalate type kidney stones and even lead to "rebound scurvy" (when megadosing stops and the body falsely reacts as if short of vitamin C).
Megadoses advocated for many conditions
As distinct from the limited use of vitamins to offset a deficiency or correct some fault, megadoses aim to saturate certain biochemical pathways in the hope of accelerating some of the body's activities to improve health or overcome complaints. In the early 1950's, some megavitamin proponents promoted the use of various vitamins in doses much higher than recommended daily amounts to treat a wide range of disorders. Megavitamin or "orthomolecular" therapy, as it was dubbed by the U. S. physicist, Dr. Linus Pauling, might involve taking 10 to 600 times the Recommended nutrient Intake (RNI) of any particular vitamin.
Many people today regularly take [B.sub.6] in far greater amounts than the recommended daily requirement, some consuming 50, 500, even 1,000 mg of vitamin [B.sub.6] each day --- truer in the U.S. than in Canada. Undeniably, vitamin [B.sub.6] is important to health. But studies show inconsistent results for the benefits of [B.sub.6] therapy. There's no proof of its efficacy in treating PMS, carpal tunnel syndrome, arthritis or other complaints, and megadosing can damage health.
Next is an article from the Nutrition Bytes repository of the University of California, Los Angeles, (Ingvild Gangsaas (1995) “Dispelling the Myths of Vitamin B6 ”, Nutrition Bytes: Vol. 1: No.1, Article 2.
http://repositories.cdlib.org/uclabiolchem/nutritionbytes/vol1/iss1/art2
Once again, I’ve edited for brevity.
“In 1942, pyridoxine (a form of vitamin B6) was determined to cause severe weakness and pathological changes in peripheral nerves and dorsal root ganglia in dogs and rats. Although the non-species-specific effects should have suggested human vulnerability to pyridoxine neuropathy, it was not until 1983 that human neuropathy was reported. In fact, further studies demonstrated that humans were even more sensitive to the neurotoxicity of pyridoxine than rodents (1).
Despite these and other compelling studies regarding the toxicity of pyridoxine, it continues to be abused. The reason behind this abuse is the existence of unscientifically founded myths. In the following, the various myths and the
startling evidence against them will be presented.
MYTH #1: Vitamin B6 is water -soluble and hence not toxic in doses exceeding RDA recommendations.
RDA recommendations of vitamin B6 range from 1.5 to 2.2 mg per day2. Extensive literature suggests that vitamin B6 is toxic in doses exceeding RDA values. The following outlines the findings of these studies (in chronological order):
(1) Seven adults developed progressive sensory ataxia and profound limb impairment of position and vibration sense after consumption of large daily doses of pyridoxine (2 to 6g) for 4 -40 months (3).
(2) Daily doses as low as 500 mg of vitamin B6 may result in neuropathy (5).
(3) Sensory neuropathy from low-dose pyridoxine occurred in individuals ingesting 0.1 to 4.0 g for 6 years (2).
(4) Photosensitive lesions, vomiting, and peripheral neuropathy developed in children with Down's syndrome being treated with high doses of pyridoxine (1).
(5) 103 women demonstrated impaired neurological function while attending a private clinic and ingesting an average of 117 + 92 mg of pyridoxine for a period ranging from 6 months to 5 years (3).
(6) Acute sensory neuropathy-neuronopathy from pyridoxine developed in an individual ingesting 61 g for 3 days (2).
(7) Excessive amounts of pyridoxine appear to cause degeneration of dorsal root ganglia (4).
(8) Daily digestion of a high dose B-vitamin was associated with an acneiform eruption that promptly improved after discontinuation of the vitamin (6).
(9) A woman exposed for 13 years to high daily doses of vitamin B6 (up to 10 g)
developed sensory neuropathy with a slight motor component (2).
In general, most patients suffering from pyridoxine toxicity complain of progressive ataxia, particularly in the dark (loss of visual cues), accompanied by numbness of the feet and severe sensory dysfunction. This dysfunction is characterized by a decrease in joint function and vibratory sense, a decrease in the sense of touch in the distal symmetric distribution, and a decrease in the sensation of the lips and tongue. Standard electrical studies reveal degeneration of large axons and small unmyelinated fibers reflecting pathologic changes in the dorsal root and gasserian ganglia (5).
http://repositories.cdlib.org/uclabiolchem/nutritionbytes/vol1/iss1/art2
REFERENCES
1. Snodgrass, R., "Vitamin neurotoxicity", Molecular Neurobiology, 6(1): 51, 61-73, 1992.
Gangsaas: Dispelling the Myths of Vitamin B6 3
Produced by eScholarship Repository, 2007
2. Morra, M., Philipszoon, H. D., D'Andrea, G., ananzi, A. R., L'Erario, R., Milone, F. F., "Sensory and motor neuropathy caused by excessive ingestion of vitamin B6: a case report", Functional Neurology, 8(6): 429-432, 1993.
3. National Research Council, Recommended Dietary Allowances, 10th Ed., National Academy Press, Washington D. C., 1989, pp. 14, 146, 220.
4. Schaumberg, H., Kaplan, J., Windebank, A., Vick, N., Rasmus, S., Pleasure, D., Brown, M.J., "Sensory neuropathy from pyridoxine abuse", NEJM, 309(8): 445-448, 1983.
5. Shils, M.E., Olson, J.A., Shike, M., Modern Nutrition in Health and Disease, 8th Ed., Vol. II, Lea & Febiger, Philadelphia, 1994, pp. 1358-1361.
6. Sherertz, E.F., "Acneiform eruption due to megadose vitamins B6 and B12", Cutis, 48(2): 119-120, 1991.
7. Moline, M.L., "Pharmacologic strategies for managing premenstrual syndrome",
Clinical Pharmacy, 12(3): 187-196, 1993.
8. Rudman, D., Williams, P.J., "Megadose vitamins", NEJM, 309(8): 488-489, 1983.
9. Weinser, R.L., Morgan, S.L, Fundamentals of Clinical Nutrition, Mosby, St. Louis, 1993, pp. 80-81.
10. Power, L.P., "Vitamin B6 accident spells relief for asthmatic patients", Food and Fitness, 1986.
4 Nutrition Bytes Vol. 1 [1995], No. 1, Article 2
Finally, I have excerpts from an editorial by vitamin B-6 adherent Bernard Rimland, Phd., Autism Research Institute, San Diego, CA.
http://www.autism.com/ari/
“In my own experience, covering almost 30 years, and many thousands of autistic children and adults, I have, to the best of my knowledge, encountered only four cases of peripheral neuropathy. In these cases the numbness in the hands and feet was noticed by the parents, who reported that the child would: a) shake the hands as though to try to get the circulation back, b) have difficulty in picking up objects, such as bits of food, or c) have difficulty walking, because of numbness in the soles of the feet. When the B6 was discontinued, or the dosage was markedly reduced, these symptoms went away very quickly and completely.
It seems that some individuals are exceedingly sensitive to larger than normal amounts of B6. These cases are very few and far between, and discontinuing the B6 seems in all cases thus far to resolve the problem.
If you contrast these findings with the findings reported on a daily basis on the drugs that are used for autism, it becomes instantly clear that the B6 is immeasurably safer. There has never been a death or serious illness associated with ingestion of even very large amounts of B6. Deaths and permanent disability from prescription drugs are commonplace.
My own son, now 40, has been taking about 1 gram per day of B6 (along with 400 mg of magnesium, and other nutrients) for some 30 years. If there is a healthier person in North America, I would be surprised. Mark's only health problem to date occurred in his early 20s, when a dentist found one small cavity in one tooth.
Despite the extraordinary safety of B6, I have been told, over the years, by thousands of parents, that their physicians have warned them against giving their children high doses of B6, because of the supposed risks involved. It is unfortunately very typical of most of the medical establishment (which of course makes its money by prescribing drugs) to denigrate and exaggerate the dangers of taking nutritional supplements.”