"Does anyone know if we still have any iodine tablets?" came the query across the fluorescent-lit, bulk bin-lined, members-only floor.

They did not, according to a co-op shopper who was there at the time. She knew this because she had just come from the cramped offices a floor above, where potassium iodide, and a lack thereof from the co-op's shelves, was a topic of intense conversation. It is widely held that this miracle elixir, a staple of the natural supplements set, can be ingested to help prevent radiation poisoning, as well as to cure other maladies.

Ever since a magnitude 8.9 earthquake destabilized the four-reactor Fukushima Dai-ichi nuclear power plant 6,611 miles away, there has been a run on potassium iodide tablets at the co-op.

Our shopper, a mom in her 30s, said that the office was being flooded with calls from concerned co-op members wondering if there were iodine tablets in stock--no--when they might be available--who knows, the suppliers are wiped out--and what alternatives there might be--bananas?

(That would be good if it was potassium you were after, but in this case, try yogurt, hard-boiled eggs or strawberries. Ideally, some strawberry-banana yogurt.)

Meanwhile, those not answering the phones were debating the ethics of hoarding the tablets. "Some people thought it was a good idea, a reasonable precautionary measure, but then the other people were like, 'Think of the people in Japan who really need it,'" our source recalled. 

There was also a thorough discussion of whether the real reason the supplier had run out was because the Obama administration had begun stockpiling potassium iodide in case of a serious emergency. It was also a concern expressed by a grandmother in Prospect Park who was chatting up our source later that day, and said she had been on the phone to her husband and son in San Diego, about 5,400 miles from Fukushima, to see if they had gotten hold of some iodine pills. They had not.

Calls and emails to the White House press office have not been returned.

Another co-op member, a 20-something male who grew up in Park Slope, confirmed that the shelves were indeed empty of potassium iodide, though he was not sure the shop had ever carried the item in question. A co-op employee told our 20-something source this, as well, raising further doubts. 

Ann Herpel, general coordinator for the co-op, allayed these fears while reigniting new ones. "Let me read you the memo our guy sent around," Ms. Herpel told The Observer over the phone. "Our distributor doesn't have it, he's sent it all to Japan. They'll be rationing the next shipment. There's a list, and we're on it, but we don't know when the shipments will start back up again."

Ms. Herpel also mentioned that the co-op had sold out of its supplies of kelp and combu, two Japanese-style seaweed products. Now might seem like a tasteless time for sushi, but she explained that seaweed is about the best source of iodine besides those now-elusive tablets. Ms. Herpel did note that the kelp sellout could merely be a coincidence, but just in case "we ordered extra and hope it will come by tomorrow."

Asked why the co-op carried potassium iodide, Ms. Herpel replied, "It's for the thyroid people." (The supplement is believed to promote thyroid health.) Asked why everyone else was suddenly so interested in the product, this being the ever-conscientious co-op, she declined to speculate. "I'm not even going to try and guess what people want it for."

Two miles away--and 6,613 miles from Fukushima Dai-ichi--Jerry Moravian knew all about the thyroid people, and it is because of them that he could not understand why the Flatbush Food Co-op in Ditmas Park is totally sold out of potassium iodide, as well. "People take it to prevent cancer in the thyroid, but there are so many other factors," the co-op manager said. "Like if you eat irradiated food or get it on your skin, this isn't going to protect you."

Mr. Moravian suggested alpha-lipoic acid as a better choice. "That's supposed to be very effective, according to some of the researching being done," he said. (The Observer cannot help but wonder if it won't soon be selling on e-Bay for 10 times its MSRP, as potassium iodide now is. If so, we have some pills we would be willing to part with for the right price.)

Mr. Moravian, who has been selling supplements for years, said these sorts of runs are not uncommon. Whenever there is a hiccup at the three-reactor Indian Point plant up the Hudson, his supply of potassium iodide will sell out. And it goes beyond radiation worries. "Every time there's a public scare, there always a run on a particular item, whether it's SARS or avian flu or something else," Mr. Moravian said.

He pointed out that, despite concerns about faraway nuclear disasters and diseases, Brooklynites still have no problem sunbathing in the park or eating fatty foods.

For those still looking for iodine, there is always salt, which is still in stock at both co-ops. And a saleswoman at Paragon Sports, the camping supply store off Union Square, informed The Observer by phone that they have iodine tablets in stock, albeit the kind meant for purifying backwoods water. Active ingredient: Tetraglycine Hydroperiodide. Does it help against radiation? "I don't think so," she said.

mchaban [at] observer.com | @mc_nyo