When it comes to supplements, natural doesn’t always mean safe.  Experts are warning that taking natural bee pollen supplements may come with the risk of suffering a serious allergic reaction, including life-threatening anaphylactic shock.

Bee pollen is used to enhance energy, vitality, memory and performance, and sometimes even to reduce allergies, though there’s little evidence to support any of these uses. It’s considered a super food because it contains proteins and is rich in vitamins, minerals and phytochemicals. It comes from the pollen that collects on the bodies of bees.

The pollen is not just from flowers but also from grass, dandelions and other plants that are responsible for springtime allergies. When taken at the suggested dose, the bee pollen extracts could contain a large amount of airborne pollen. It also contains saliva from bees.

A new report, published in the Canadian Medical Association Journal, describes the case of a 30-year-old woman who started to take bee pollen and a few other supplements. On day two of her new supplement regimen, she had to be rushed to the emergency room because her eyelids, lips and throat began to swell, and she had difficulty swallowing, shortness of breath and felt faint. Doctors discovered she had suffered from seasonal allergies in the past. The bee pollen apparently put her over the edge.

Though there are not a lot of reports in the science literature on how common or rare reactions are to bee pollen, one Italian study found that, between 2002 and 2007, the Italian national surveillance system for natural health products received 18 reports of adverse reactions associated with propolis, a bee pollen product.

Less scientific, though also troubling, anecdotes of severe reactions abound on the web, even on websites hawking bee pollen.  Though one website says that serious reactions are rare, at the same time, they advise anyone taking bee pollen to do a “tolerance test” by starting with one raw bee pollen kernel and putting it under your tongue and slowly increasing your dose each day. The website warns users not to jump straight to a tablespoon of pollen during the first week or so of using the pollen.

Patients with allergies to pollen or bee stings may be at particular risk. Studies that have done skin prick tests on patients found a strong association between being allergic to bee pollen and having allergies to various grasses and other airborne allergens.  But there have also been cases reported in people with no history of allergies.

Another problem is that aside from causing a serious reaction, using these supplements may set off an allergy to pollen and bee stings that a person may have never previously experienced, making him or her susceptible of anaphylaxis in the future. That may not be a risk people want to take.

Laurie Tarkan is an award-winning health journalist whose work appears in the New York Times, among other national magazines and websites. She has authored several health books, including "Perfect Hormone Balance for Fertility." Follow her on Twitterand Facebook.