|Is Vitamin B-6 Safety a Political Issue
in the United Kingdom?
October 9, 1997
Recently officials in the United Kingdom announced that they were going to limit the amount of vitamin B-6 (pyridoxamine) permitted in vitamin formulations sold in health food shops to 10 milligrams. However, vitamin formulas sold in chemist shops would be permitted to have 50 milligrams of vitamin B-6, higher levels available with a prescription.
The scientific literature shows no toxicity reports below 500 milligrams per day over long-term usage. One report, which is not generally accepted due to design flaws, and which also has no statistical significance, suggests the toxicity could be lower.
The Solgar Vitamin and Herb Company has taken issue with this arbitrary action. Our Technical Director, Stephen Terrass, has replied as follows.
Mr Jeff Rooker MP
September 12th, 1997
Dear Mr Rooker,
I have just received a copy of your latest correspondence to fellow MPs regarding vitamin B6. After reading this document, I feel compelled to point out several facts:
1/ You have been misled about or appear to misunderstand several key facts concerning the B6 issue.
2/ The general public is outraged by this proposal.
3/ The general public will lose convenient access to this important nutrient if the current proposals are made law.
4/ Prescribed B6 will generally be more expensive than that currently on free sale.
5/ GPs will be stretched by the extra workload if B6 over 50mg is prescription-only.
6/ PMS Help, a group that supports the Government position, is run by the daughter of Dr Katharina Dalton.
7/ There are no restrictions in the United States on B6.
8/ The Consumers Association, though no doubt well meaning, has little expertise in this specialist field.
9/ Scientists agree that the Dalton study is flawed and should not be taken into consideration.
10/ As to the much-cited 'dog study', the researchers themselves, have disputed the Government's interpretation of their study.
11/ The Committee on Toxicity is not an independent body (please see enclosed documentation). Many of the members of this influential committee receive funds from pharmaceutical companies.
12/ The Government's action at this time is in danger of undermining EU and Codex discussions.
Considering the severe implications to the health food retailer, the supplement manufacturer/exporter and most importantly, the health and health freedom of the British public, it is essential that neither the public nor the legislators are inadvertently misled.
I will address the points one by one so that you can cross-reference this letter with your documents.
You begin by suggesting that the campaign to inform the public about the implications of your decision about B6 is based on the financial pressure it would place on the natural products industry. Obviously the proposed restrictions would be financially detrimental to retailers, manufacturers and distributors of dietary supplements; however, do you honestly believe that tens of thousands of letters from private citizens could have been generated in such a short space of time unless these people sincerely disagreed with your decision?
The natural product industry is comparatively small, and is hardly capable through its own means of stimulating such a fervent and voluminous response in consumers unless the consumers themselves are already concerned about the issue. All that is required is to make the consumer aware of the proposal and to inform them of the wider body of research that, unlike the Dalton study, has been accepted as valid by the vast majority of scientists who have reviewed it. I can't imagine that you or your colleagues have received many letters supporting your action on B6.
You have stated that the Government's prime concern is 'to protect the public health by ensuring that products sold as foods are safe'. Nobody would argue that this is a laudable position to take; however, not only is it scientifically inappropriate to make B6 a target in your crusade, it is particularly ironic that an essential nutrient to health should be your first endeavour in your new position.
Cigarettes kill over 100,000 UK citizens every year. Vitamin B6 has never killed anyone, and in the doses that you seek to ban for free sale, it has never been proven to harm anyone either. Never mind the scientifically proven health benefits of B6 (which pertain primarily to the levels that are to be banned). So in a few months time I, and every person living in Britain, will be able to kill ourselves with lung cancer from smoking, but we will no longer be able to exercise our health freedom by purchasing a beneficial nutrient in harmless dosages.
Paracetamol kills hundreds every year, and this, too, will be available for free sale in every corner shop, every petrol station, and every supermarket - but not B6. The list of examples of this nature is considerable, but I suppose the tobacco and especially the pharmaceutical giants can make a lot more threatening noises against restrictions than health food stores or vitamin companies. Yet, how many peer-reviewed studies can you cite that show that smoking does not cause lung cancer, or that paracetamol is not the cause of hundreds of deaths from liver failure each year? Not one.
Your next point is that you have received support from the Consumers' Association and the PMS Help organisation. If you had been aware of the stance of the Consumers' Association (CA) toward the natural product industry over the years you would have seen that their opinions seldom concur with the current scientific opinion. This is not surprising, considering that the CA rarely cites scientific references for the information they print in their health publication on such issues. It is interesting to note that in the past couple of weeks the CA was heavily criticised by the Advertising Standards Authority for their ill-informed reporting. The publication Marketing, which reported on the ASA dismay (21 August 1997), also called into question the independence of the CA. Marketing also seemed to be suggesting that this was not the first instance where the CA's independence was subject to question.
What is even less surprising is your reliance on the support of the PMS Help organisation. Perhaps you are unaware that PMS Help is run by the daughter of Dr Katharina Dalton, the researcher who co-authored the much-criticised study that you have used as part of your basis for the restriction in the first place. The fact that PMS Help advises against B6 in the treatment of premenstrual tension is also not surprising, as Dr Dalton runs a treatment clinic for PMT that features the drug progesterone.
I can only assume that these were the only organisations that have given you their steadfast support. Considering the above information, this fact hardly supports the credibility of your proposed restriction of B6. I am aware that it was the Consumers' Association that originally requested restrictions on B6 in the first place, without any consumer pressure on them to do so.
A big question that has to be asked is: Why has there never been a restriction, or even an investigation ordered regarding toxicity concerns about B6 in the ten years since the Dalton and Dalton paper came out?
It is obvious that there are two major reasons for this. Firstly, so many scientists have debunked the Dalton study over the years that nobody would have been able to justify such action. Secondly, there has been not been a deluge of case reports of B6 neurotoxicity to create any concern. As a matter of fact, just recently a Government medical toxicology unit carried out a study to assess the safety of nutritional supplements and natural remedies. Mrs. Angela Browning, who was then the MAFF Parliamentary Undersecretary was questioned by Mr Peter Hain MP as to whether there were any cases of reported toxicity with respect to B6, and she admitted that there had been none.
It is clear that the Dalton study is sufficiently flawed to make it an inappropriate basis for legislation. According to many scientists, it is sufficiently flawed to make it inappropriate to draw any firm conclusions whatsoever. Even in the Government's own press release on the subject, the Dalton and Dalton study is referred to as being 'methodologically deficient'!
And this brings us to the only other piece of 'evidence' you have put forward for your proposal - that of the 23-year-old dog study by Dr Ian Munro and Dr John Mills. It is now on record that they have commented very strongly against your intention to restrict B6 on the basis of extrapolating their data to humans. As a matter of fact, when questioned about this, Dr Mills stated, "to make judgements on this study of a few dogs and to extrapolate to humans is utter nonsense". Dr Munro went on to label the 300 safety factor that your consultants devised for this extrapolation as "inappropriate".
Regarding your claim that the public will not lose access to the higher doses of B6, due to the route of prescription is also misleading. Perhaps you are unaware that GPs receive only a few hours of nutritional training in medical school, and are typically ill-informed (often by their own admission) in the potential (and scientifically-proven) applications of most vitamins and minerals. Consumers who are taking higher levels of B6 based on the benefits they have always received from the nutrient will invariably find it very difficult, if not impossible, to convince their doctor to prescribe B6 to them. I am also aware that licensed products of nutritional origin have generally been far more expensive than an unlicensed version of the same potency of the same nutrient off the shelves of a health food store. Even if the prescription charge is less than the cost of the nutrient over the counter, the excessive price of such products is still paid for by the public in their National Health Insurance payments. Obviously the higher price the National Health Service has to pay for such products does not do the Government any good either. Of course, once the manufacturers supplying health food stores with B6-containing products (e.g. multiple vitamins, B-complex formulas and B6-only products) have been sufficiently damaged by such a restriction, the pharmaceutical companies, who can afford the exorbitant and unnecessary cost of licensing, will be poised to fill the void.
In your letter you state that "perhaps it is worth emphasising the point that the COT is a committee composed of independent experts". I find it most interesting that the Government considers shareholders, consultants and employees of pharmaceutical companies "independent". We have written evidence, supplied by the Department of Health, that several of the prominent members of the COT are shareholders, consultants, employees and/or are receiving pensions from pharmaceutical companies. The following list was extracted from the DoH report 1995 Membership of the Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment (COT)- [see attached report]. This is the most current report at the time of this writing, and it is doubtful that there have been many significant changes in the details of members or their financial interests since its publication. The following are examples of pharmaceutically-based financial interests of the COT:
Professor H Woods (Chairman of COT)
The fact that the pharmaceutical companies have the most to lose by consumers improving their health through using un-patentable nutritional products makes the COT connections especially suspicious. I might suggest that you investigate this further, because the COT is anything but independent. Quite frankly, the media would have a field day with this issue.
The Food Advisory Committee (FAC) is also susceptible to commercial bias, as many of its members, too, have financial interests - in this case with major food producers (see attached report). It is worth mentioning here that many of these companies are involved in producing foods that are well known to compromise the public health (e.g. 'junk foods', soft drinks, sweets, etc.) - thus clouding the FACs position on protecting the public health. In addition, the commercial food industry is hoping for the floodgates to open for health claims to be allowed on various products (known as 'functional foods'). I have personally been asked to speak at two recent food industry conferences on this subject, and I gathered from my discussions with delegates that many food companies consider the growth in the use of dietary supplements an impediment to the success of such products. Now to attempt to clarify my position further, I will address some of the specific points in the notes with your letter.
The COT's view on B6 toxicity is consistent with the EU and French levels.
This is not surprising. The United States and Britain possess a great deal of experience with respect to nutritional research, and many EU countries lag very far behind. Up until now, the British Government has favoured (on the basis of research data and historical evidence of safety) a liberal policy on vitamins and minerals. As MAFF is well aware, there is absolutely no consensus whatsoever in the EU as to the best method of dealing with dietary supplements. You may also be aware that much of their difficulties in formulating policies regarding supplements stems from two main issues, 1/ With the exception of Britain and The Netherlands, the countries in the EU have little historical availability of higher dose supplements. 2/ Most countries in the EU do not possess the long term experience and expertise in assessing nutritional research in comparison to countries such as the US or UK. Hence they can not even come to agreement on the basis upon which to legislate, much less what appropriate levels of nutrients should be allowed. It is no coincidence that the two countries in the world that carry out the greatest volume of nutritional research (including that which pertains to toxicology) have the fewest restrictions on the levels of nutrients allowable for free sale.
The Government abides by the Reference Nutrient Intake (RNI) as a gauge of how much B6 is needed.
The RNIs (formerly RDAs) have been criticised by many leading nutritional researchers. One of the main criticisms is that they pertain merely to the prevention of overt deficiency diseases (e.g. scurvy, rickets, beri beri, etc.) and have no proven relevance to optimal health and certainly not to therapeutic use. Of course, the levels one needs is not really the issue anyway, as never have products sold as food had their legal status vetted on the basis of need. If this were the case most foods found in supermarkets would be illegal, and presumably possession of cigarettes and alcohol would be a felony.
Medicinal products containing vitamin B6 are assessed for safety and efficacy by the MCA.
The safety of vitamin B6 products currently available for free sale are no less safe than the B6 in licensed products. As you state later in your points, medicines are assessed for benefit vs. risk. If the benefit vs. risk has been determined to be satisfactory for licensed B6 products, then the same should be true for unlicensed B6, as the chemical compound of B6 itself is generally the same in both types of products.
There have been reports under the MCA's voluntary Yellow Card Adverse Drug Reaction reporting scheme of adverse reactions associated with medicinal products containing B6.
You mention that since 1964 there have been 649 reports of 1181 spontaneous reactions associated with such products, of which 16 were fatal. I'm sure you will appreciate that it would be easy for an MP to misconstrue your wording to mean that some of the fatalities were due to B6. I would suspect that you can confirm that, in fact, all of the fatalities were associated with multiple agent medicines that just happened to contain B6, lest anyone be inadvertently misled. You do go on to say that the majority of reactions were due to medicines with a number of constituents, which is not surprising since many, if not most, of the preparations in question will contain drugs possessing toxicity many times greater than B6. As it happens, a total of 410 'reactions' to anything in a pill form over a thirty-three year period is incredibly low. As a matter of fact, it is not unusual in clinical trials for 'adverse reactions' to be reported after the consumption of placebos. In addition, a report of a 'reaction' could mean any reaction - including feeling queasy or similarly ambiguous symptoms that could have been coincidental. The reporting scheme is merely voluntary reports, as you say - not a confirmation of the origin by medical examination.
The COT made recommendations after considering over 100 scientific papers.
The COT may have looked at over 100 papers, but the truth is, that only the methodologically deficient' (your words) Dalton paper adheres to the belief that B6 neuropathy has occurred with as little as 50 mg of B6. Not a single other study has reported such a concern at a level anywhere near 50 mg. The suggestion made in an earlier correspondence of yours to MPs stated that the symptoms reported in the Dalton and Dalton study were consistent with B6 neuropathy. Dr Alan Gaby, an American physician who happens to be a published expert on B6, has stated that the symptoms reported in the Dalton and Dalton study were not consistent with B6 neuropathy, but were consistent with common symptoms of premenstrual tension, for which the patients had been treated.
The factors the COT used regarding the animal study are well established.
The use of such a calculation is often used to estimate safety levels, in tandem with other data - but this applies to pharmaceutical drugs, not essential nutrients. As mentioned earlier, the authors of the dog study, which you have used to decide on the proposed limit of 10 mg, have suggested that the use of their data for this decision is scientifically inappropriate.
B6 will continue to be available for therapeutic use from pharmacies and on prescription.
To clarify, you have earlier stated that 50 mg or more will be prescription only. I have already addressed this point in an earlier part of this letter.
Why place restrictions on B6 while allowing the sale of far more dangerous drugs? Medicines are only authorised when the risks are appropriate in relation to the expected benefit in treating a medical condition.
Does this mean that you consider the benefits of smoking cigarettes to outweigh the risks?
Proposed controls will force health food shops to close. Initial estimates by manufacturers suggest that B6 supplements account for less than 4% of the nutritional supplements industry.
Considering the lack of thoroughness in assessing the research of B6, or for that matter, the 'independence' of the COT consultants, it is not surprising that this was the Government's answer to this question. What you neglected to mention is the fact that this proposed legislation does not only affect B6 preparations. The 4% refers to B6-only supplements, but the proposed legislation would eliminate almost every multiple vitamin product and B-complex product on the shelves of health food stores. Multiple vitamins collectively represent the largest selling category of nutritional supplements in health food stores in the UK, and account for a substantial amount of their profitability.
As far as we are aware there are no restrictions in the United States equivalent to those proposed for the UK. However there are many countries where controls are far more strict than those applying in the UK.
To clarify this issue for your own benefit, there are no restrictions on B6 in the United States. The US is involved in more research, including toxicological research, into vitamins and minerals than any other country. They have not deemed B6 appropriate for any restrictions, and toxicological reviews on B6 carried out by the country's leading toxicologists have stated that the LOAEL (lowest observed adverse effect level) for B6 is 500 mg - ten times higher than that suggested by COT and fifty times higher than the limit you have proposed for free sale! The LOAEL of 500 mg is based on the toxicologists taking all the existing research into consideration and assessing it for its quality and scientific credibility. It is interesting to note that one of the vitamin and mineral safety documents that lists the LOAEL at 500 mg (published this year) is authored by Dr John Hathcock, a renowned toxicologist who is a former member of the US Food and Drug Administration (FDA).
The EU Commission and other Member States are well aware that the UK believes that controls on dietary supplements should be based on safety considerations.
The UK natural products industry is in total agreement with this stance, and this is precisely why it opposes the proposed limit on B6 at 10 mg. This proposal is not based on safety, but rather on a figure that can not be supported by credible and/or appropriate scientific data.
I am concerned that your proposal on B6 will undermine the UK Government's own intention of having the safety of all nutrients assessed by the EU on the basis of sound science.
It is clear that other Member States are less experienced in assessing vitamin and mineral safety parameters than the UK. It is also clear that the UK would like to preserve the liberty of its citizens to choose to take higher potency vitamin and mineral supplements, as they have done safely for decades. The only way this is going to be achieved is if the UK shows a clear adherence to sound science in its decisions related to supplements on a national level. As you are probably aware, several Member States are actually opposed to EU legislation on dietary supplements being based on safety. Many members of the world's scientific community have been very critical of the UK Government's proposal on B6, and this criticism is likely to be publicly aired in the following weeks. Unfortunately for the UK citizens and its Government, this criticism may well cause other Member States to question the qualifications of the UK Government in influencing EU dietary supplement policy.
In conclusion, the natural products industry has served the public for many years by following the policy of safety first.
A new product launch is assessed first on its safety, secondly on its quality of formulation and finally on consumer demand. The natural products industry, and the supplement-taking public, deserves better treatment than it has so far received from the New Labour Government.
More than half the UK population is now taking dietary supplements - they deserve your respect for their capability to make intelligent choices - the American Government respects those choices - why doesn't the UK Government?
I respectfully ask you to consider the points I am addressing in this letter, assign a truly independent committee to evaluate the scientific data, and for you to act on those results in consultation with the natural products industry.
More broadly, the European Union and Codex are examining the area of dietary supplements - why not simply adopt the US framework and dedicate the time of these worthy beaurocrats to a more appropriate cause.
Thank you for your attention to this matter, I look forward to your response.
BRITISH GOVERNMENT MOVES TO RESTRICT VITAMIN B 6
On July 4, 1997, the newly elected Labor Party in England took steps to limit the maximum dose of pyridoxine (vitamin B6) for over-the counter sale to 10 mg per tablet. The ostensible purpose of this proposed legislation is to increase public safety. It is well known that ingestion of very large doses of pyridoxine (5oo mg/day or more) can cause sensory neuropathy in humans. In addition, dogs that consumed the human equivalent of 3,000 mg/day developed pathologic changes in sensory neurons
Based on its potential for toxicity, caution is certainly warranted with very large amounts of pyridoxine. However, limiting the dosage to 10 mg per tablet is a gross over-reaction that could pose a threat to the public health. There has never been a credible report of pyridoxine toxicity occurring at doses of 200 mg/day or less (1). Furthermore, there is substantial evidence that ingesting more than 10 mg/day of this vitamin could improve the health of a large proportion of the population. Restricting the dose of vitamin B6 to 10 mg per tablet would therefore harm millions of people, while helping virtually no one.
The British Committee on Toxicity (which advised the government) appears to have blundered in its decision-making process. Not only did this committee make an unreasonable aggressive extrapolation from animal data, it also relied on a hopelessly flawed report by Dalton (2) which claimed that low doses of pyridoxine (less than 50 mg/day ) can cause neurotoxicity in humans.
Increased Vitamin B6 Requirements
The RDA for vitamin B6 is about 2 mg/day. However, the RDAs were designed to prevent serious deficiency diseases, not to promote optimal health. During the past 40 years, our environment has been inundated with toxic chemicals (particularly hydrazines and related compounds) which are known to interfere with the utilization of vitamin B6. During that same time, there has been an increase in the prevalence of a number of vitamin B6-responsive disorders, including carpal tunnel syndrome, asthma, kidney stones, premenstrual syndrome (PMS), and attention deficit-hyperactivity disorder. There is reason to believe that the presence of vitamin B6 antagonists in our food, water and air has created a new epidemic of pyridoxine dependency. In other words, people living in industrialized societies may need much more vitamin B6 than they did in the past (3).
Research has shown that vitamin B6 (usually in doses of 50 to 200 mg/day) can prevent or relieve the symptoms of carpal tunnel syndrome, PMS, asthma, and depression associated with the use of oral contraceptives. Higher intakes of pyridoxine may also help prevent certain complications of pregnancy, including nausea and vomiting, gestational diabetes, intrauterine growth retardation, and toxemia. In addition, there is evidence that vitamin B6 supplementation can reduce the risk of cardiovascular disease (by lowering homocysteine levels) and can prevent recurrences of calcium oxalate kidney stones (by inhibiting the production of oxalate).
Flawed Review of Safety Data
Vitamin B6 has been used in doses up to 200 mg/day by numerous clinicians for many years. None of these doctors (except Dalton) has seen evidence of neurotoxicity at these doses. The method whereby the Committee on Toxicity arrived at a "maximum safe dose" of 10 mg therefore warrants close scrutiny. In compiling its recommendations, the Committee relied mainly on the dog study and the Dalton report.
The Committee acknowledges that the human equivalent of 3,000 mg/day is required to produce toxicity in dogs. However, the Committee arbitrarily divided that amount by a "safety factor" of 300, to arrive at a "safe" dose of 10 mg. While it is appropriate to use a large "safety factor" for toxins such as lead, dioxins, and PCB's (which have no known health benefits), application of that principle to essential nutrients can result in bizarre recommendations. For example, ingestion of 3,000 mcg/day (300-fold less than the toxic dose) would not be enough to prevent selenium deficiency. Likewise, the nutritional requirements for zinc, copper, manganese, potassium, magnesium, vitamin D and other nutrients are much higher than the toxic dose divided by 300. And if one's water intake were reduced by 300-fold compared with the amount that induces water intoxication, then one would probably die of dehydration. Thus, the "safety factor" used by the Committee on Toxicity was excessively large and reflected a poor understanding of nutritional science.
Similarly, the Dalton study, which was so flawed as to be uninterpretable, cannot reasonably be used to support the British government's position. Dalton, who runs a PMS clinic in London, is a well-known advocate of progesterone therapy for PMS. After the syndrome of pyridoxine neurotoxicity was reported, Dalton began asking her patients who were taking vitamin B6 whether they experienced certain symptoms. Approximately 60% reported a history of one or more of the following: paresthesias, hyperesthesia, bone pain, numbness, or fasciculations. Some 20% of the women with these symptoms had been taking less than 50 mg/day of vitamin B6. According to Dalton, the symptoms that these women described were manifestation of pyridoxine neurotoxicity.
In fact, those symptoms are quite common and are usually not indicative of a neurologic problem or a serious medical disorder. Rather, they are often caused by minor metabolic disturbances such as reactive hypoglycemia, food allergies or magnesium deficiency- the very same abnormalities that plague many women with PMS. Amazingly, Dalton did not bother to include a control group in her study. Consequently, we have no way of knowing whether paresthesias, hyperesthesia, bone pain, numbness, and fasciculations are related to taking B6 or are merely symptoms which commonly occur in women with PMS. It is noteworthy that not a single nutrition-oriented physician has confirmed Dalton's observations.
Proponents of dosage limitations argue that most of the indications for "high-dose" vitamin B6, constitute "medical therapy" and should there fore require a doctor's prescription. Since the new law in England would still allow 50-mg tablets to be sold by prescription, government officials apparently believe that availability will not be a problem.
The issue of how, "medical therapy" should be defined and who should control it have been vigorously debated on both sides of the Atlantic. However, a more practical matter at the present time is that making 50 mg of vitamin B6 a prescription item would create a new set of problems. Since most doctors know close to nothing about vitamin B6, they may be reluctant to prescribe it. Women requesting vitamin B6 for their PMS might instead be given Prozac, and people with carpal tunnel syndrome may be told they need steroid injections or surgery. Even if doctors did know how to use vitamin B6, requiring a prescription would place an intolerable burden on both the economy and the health care system. There is no reason that millions of people should have to miss a half-day of work, just to see their doctor for a bottle of vitamin B6. Nor should overworked physicians be subjected to the useless task of evaluating millions of people who merely want to take a safe dose of a vitamin. And, while 50 mg/day of pyridoxine currently costs only about $2.00 per month, the price would probably increase ten-fold if it became a pharmaceutical product.
The British public is currently engaged in a vigorous campaign to prevent the government from following through on its ill-conceived plan. So far, this intensive grass-roots effort has succeeded in delaying the final decision until January 1998, but the government has given no indication it will consider changing its policy.
What You Can Do
So, why should Americans care about problems that are occurring on another continent? One reason is that what happens in England may eventually spill over to the United States. At the United Nations, the Codex Alimentarius ("food law") Commission is working to create international rules and regulations related to foods and nutritional supplements. What happens in England will likely influence the Codex recommendations, which could affect the availability of high-potency supplements in the United States.
The other reason to be concerned is that restriction of vitamin B6 would represent a triumph of "junk science" over reason, creating the dangerous precedent of using excessively large "safety factors" to arrive at an unreasonably low "safe limit" for a nutrient. Next thing you know, they could be putting 20 IU of vitamin E on prescription.
For those of you who hear the call to action, there are several things you can do. If you are a practitioner, please send a letter describing how you have used vitamin B6 safely in daily doses up to 200 mg. Financial contributions are badly needed. Contributions payable to Consumers for Health Choice (denominated in British currency -- i.e., pounds) should be sent to:
This donation is not tax-deductible. But, governments have rarely been known to subsidize their critics.
Alan R. Gaby, MD
911 Tyler Street,
1. Gaby, A. The safe use of vitamin B6. J. Nutr. Med. 1990;1:153-7
Reprinted with permission from the October 1997 issue of "Townsend Letter for Doctor's and Patients."
For information on how B6 can help with carpal tunnel syndrome, please see "Vitamin B6 Deficiency Linked to Carpal Tunnel".