Panic over the radiation from the quake-crippled Fukushima Dai-ichi nuclear power plant in Japan is sparking a sudden surge in sales of iodine pills around the world -- even as health experts warn that the pills may be of little use.

Since word emerged that Japan has begun distributing potassium iodide tablets to residents near the Fukushima facility, other global regions have noted a spike in sales of the pills.

In Russia's Far East, not far from Japan, residents are buying up the pills in droves, according to a report in the Wall Street Journal -- even as the Russian government insists that radiation levels in Russia remain at normal levels.

There are reports that packets of potassium iodide pills are attracting bids of up to US$540 on eBay. And British Columbia's top medical officer, Dr. Perry Kendall, also noted a run on iodine tablets. He said the pills are unnecessary and asked drug stores not to sell them.

"It is recommended that pharmacies do not dispense or stockpile potassium iodide tablets," he said in a Monday news release.

"The consumption of iodide tablets is not a necessary precaution as there is no current risk of radiological I131 exposure. Even if radiation from Japan ever made it to British Columbia, our prediction, based on current information, is that it would not pose any significant health risk."

The buzz over the pills even compelled the World Health Organization to use Twitter to call for calm.

"Consult your #doctor before taking #iodine pills. Do not self-medicate!" the WHO wrote on its Twitter page Monday evening.

The WHO also used Twitter to caution against drinking iodine antiseptic, noting, "it will not protect you & might be harmful when taken orally."

Some drug stores and health food stores have reported shortages of the tiny white pills. But Canadian manufacturer, BGR Chemical Products, tells CTV News that even before the Japan crisis, there was already an iodine shortage.

The Quebec-based company's Chris Merrill tells says there has been a worldwide shortage of iodine for some time now. He notes the chemical is used in the manufacturing of LCD screens and TVs, and Chile, the world's largest iodine supplier, has had trouble meeting demand.

Despite the sudden interest in iodine pills sparked by the Japan crisis, health officials have been quick to note that potassium iodide is not an anti-radiation pill.

Potassium iodide can help prevent thyroid cancer after radiation exposure, by reducing the amount of radioactive iodine absorbed by the thyroid gland. But the pills cannot protect other organs from the effects of radiation exposure.

As well, the pills block only radioactive iodine, not other materials, such as radioactive cesium, which has also been detected outside the Fukushima facility.

What's more, iodine pills need to be taken very carefully. A single dose of potassium iodide, which also goes by the abbreviation KI, protects the thyroid gland for only 24 hours.

In some cases, it may be advisable for those exposed to radioactive iodine to take one dose of KI every 24 hours for a few days. But taking a higher dose of KI, or taking KI more often than recommended does not offer more protection. It can cause severe illness or death, warns the U.S. Centers for Disease Control.

Some of the immediate side effects caused by KI may include stomach upset, allergic reactions (possibly severe), rashes, and inflammation of the salivary glands. Over the long term, too much potassium iodide can cause severe headaches, confusion, irregular heartbeat, and numbness, tingling, or weakness in the hands.

There are also those who point out that when it comes to radioactive iodine, the greatest danger is not from absorbing it from the air but from ingesting it in contaminated food and milk weeks after a radiation leak.

But Dr. David J. Brenner, director of the Center for Radiological Research at Columbia University, believes that the epidemic of thyroid cancer after the Chernobyl disaster probably could have been prevented if the government had immediately stopped people from drinking the milk from cows that had grazed one contaminated grass.