To the Editor: The report by See and colleagues on an accidental death from acute selenium poisoning1 draws attention to a misconception among some health-conscious consumers that, because selenium is obtainable without a prescription, it is safe to take in high doses.

Selenium is available over the counter in tablets containing as much as 200 μg. The only advice printed on packs is not to exceed the recommended daily intake, which is not specified (the current Australian values are 70 μg and 60 μg per day for men and women, respectively). There is no mention of the upper limit of 400 μg, beyond which there is risk of toxicity.

Selenium supplements are consumed by many people worldwide. Up to 9% of adults in the United States use these supplements.2 Consumption is much the same elsewhere in the Western world. They are used by many in the belief that their dietary intake of selenium is inadequate, and that the supplement will protect them against a variety of illnesses.

Consumers get information from several sources, not least the general media and the Internet. These sources can seriously mislead, especially when they misinterpret the results of clinical trials and make exaggerated claims of health benefits. Those who rely on such popular, but simplistic, information can reach false and sometimes dangerous conclusions.

Health advisors who become aware that patients are self-medicating with selenium need to point out the dangers. Unfortunately, after years of teaching students of medicine and other health-related fields about trace elements, I know that many graduates do not have enough knowledge in this area to provide accurate guidance. Even if they want to learn more by consulting current literature, the sheer volume of articles can deter them. It is for this reason that I wrote the book Selenium in food and health3 — to provide an up-to-date, scientifically based review of the nature and role of selenium in human health and metabolism. I hope that the book’s readable and user-friendly style will make it easy for overburdened professionals to learn enough about this element to help prevent the sort of tragedy described by See and colleagues.

To the Editor: It is of great concern to me that the recent case report Accidental death from acute selenium poisoning by See and colleagues1 inappropriately cast doubts on the safety of complementary and alternative medicines (CAM). This incident should be placed in its correct context.

The guidelines are clear for listed complementary medicines (ie, compounds or formulas registered and approved by the Australian Register of Therapeutic Goods for distribution in Australia).2

As a trace element, selenium is required in microgram amounts. The Therapeutic Goods Administration stringently regulates its use in nutritional supplements in Australia, with an allowed limit of 26 μg per daily dose (as selenomethionine) in unrestricted products, and 50 μg per daily dose (as selenite) in restricted, pharmacy-only supplements.

This is considerably less than the “no observed adverse effects level” for selenium, which is as high as 400 μg per day,3 as noted by See and colleagues. Furthermore, even at these low doses, CAM products that contain selenium must carry substantial “red flag” label warnings. Bulk sodium selenite powder — the form which led to this fatality — is definitely not dispensed as a complementary medicine.

Nevertheless, the authors of the case report conclude that “adverse outcomes of complementary and alternative medicines should be better publicised and more stringently reported to the Adverse Drug Reactions Advisory Committee (ADRAC)”.

While this may be a commendable recommendation, it is inappropriate and incongruous with the findings presented in this case report. Furthermore, the sodium selenite used by nutritional doctors is administered as a liquid at a dose of 50 μg per drop, and is a restricted S4 prescription-only product.

To achieve a dose of 10 g of sodium selenite, as taken by the reported patient, would require ingestion of 115 bottles of the registered S4 supplement or, even less plausibly, 400 000 doses of a listed CAM supplement. Neither of these preparations was implicated in the reported case.

So why then are the authors of this case report asking for increased vigilance for complementary medicines? It is surely the interchange between the pharmacist and the customer that lies at the heart of this matter. Had a listed selenium product been dispensed, this poisoning would not have occurred.

To the Editor: I wish to address a statement made in a recent case report in the Journal entitled Accidental death from acute selenium poisoning.1 The authors claim that the death of a 75-year-old man after ingesting 10 g of sodium selenite “exposes the myth that natural therapies are inherently safe”.

The patient actually purchased sodium selenite powder and tablets. This is a restricted substance and an industrial chemical which would certainly have been labelled a poison.

It should be noted that the maximum recommended daily dose of selenium in complementary medicines in Australia is 52 μg.2 The authors of the case report do point out that the patient took more than 10 000 times the recommended dose of selenium which would be available from a medicine. (My calculations put this closer to 20 000 times.) An individual drinking more than 10 000 times even the daily recommended amount of water would probably not end up in much better shape. Is this evidence of an underlying agenda to discredit natural products?

The Complementary Healthcare Council of Australia recommends that consumers take steps to thoroughly inform themselves about products, preferably by asking their health care practitioner. We also urge them to inform their health care practitioner of which medicines, complementary or otherwise, they are taking.

The incident involving the sodium selenite is regrettable, but for the authors to link the product and this case of fatal ingestion to exposing the myth that natural therapies are safe is, at best, ridiculous, with no foundation.

They also state that adverse reactions to complementary and alternative medicines should be better publicised and more stringently reported to the Adverse Drug Reactions Advisory Committee. Adverse reactions are routinely reported and publicised for all medicines, and have been for some time, as any check of the website of the Therapeutic Goods Administration will show.3,4

I agree with the authors that the case highlights the dangers of consumers’ reliance on the Internet. Local Internet sites that advertise therapeutic goods must conform to the requirements of the Therapeutic Goods Advertising Code, as well as the Therapeutic Goods Act 1989 (Cwlth) and Regulations. However, overseas sites are not necessarily regulated or policed, and may provide inappropriate and misleading information. While our industry’s products are low risk, they should be taken, like other medicines, with due care.

In reply: The myth we referred to is the commonly held misperception by a significant percentage of the population that natural therapies are inherently safe. As Lewis and Brighthope very correctly point out, the dose ingested by our patient was hugely in excess of any recommended maximum. We believe this is evidence of the misperception, as most patients would not dream of taking 10 or 20 thousand times the maximum dose of “non-natural” remedies, because they recognise that all such remedies have side effects. Our patient’s confidence that he could safely take such a huge dose was, we consider, at least partly a consequence of his belief in the myth that natural therapies are safe.

The fact that the dosage of selenium in nutritional supplements is strictly regulated does not prevent problems such as this — where patients obtain information of variable quality on the Internet, make their own arrangements to obtain the product, and then ingest a toxic amount.

Our article was in no way part of “an underlying agenda to discredit natural products”; it merely highlighted the risks inherent in self-medication based on information of variable quality obtained from the Internet, coupled with the impression that natural therapies are inherently safe. We hope that our call for adverse outcomes of complementary and alternative medicines to be better publicised will go some way to preventing such a tragic error occurring again.