Sales of vitamin D have soared following a study suggesting the vitamin could prevent cancer.

'The companies are going to be back-ordered on vitamin D.'— Naturopath Milenka Jonas

Pharmacies and health food stores in Charlottetown and Montreal sold out over the weekend. Montreal naturopath Milenka Jonas told CBC News demand has been incredible, and she's concerned she won't be able to get more very quickly.

"The companies are going to be back-ordered on vitamin D right now so they're going to have to manufacture it. That takes a while," said Jonas.

With demand so high, supplies are likely to be tight for the next two weeks, Jonas believes.

The rush follows a recommendation by the Canadian Cancer Society that people take vitamin D to help prevent cancer. The society was responding to an American study that showed people living in northern latitudes aren't getting enough vitamin D from the sun, and taking supplements could reduce the risk of certain cancers by 50 per cent or more.

The cancer society said taking supplements was especially important in winter — when the sun isn't strong enough for the skin to make the vitamin — and for people with dark skin, who don't make vitamin D as efficiently.

Hoping for more stock

Kilby Rinco, a pharmacist with the Friendly Pharmacy in Charlottetown, said that despite selling out on the weekend, she's expecting to have more vitamin D in stock on Monday.

"It's not usually one of those things that we sell 10 to 15 packs in a day, but that's what's been happening here."

Rinco said sales are up 50 to 75 per cent. One Montreal health food store reported a much higher increase late last week, with bigger sales every day than they normally have in a week.