Why is it dangerous to eat a polar bear's liver?

Research has shown that a healthy adult person can tolerate 10,000 units of vitamin A. Trouble, if it comes, comes between 25,000 and 33,000 units. One pound of polar bear liver — a fist-sized chunk and barely a meal — can contain 9 million units of vitamin A. The occasional lack of liver toxicity that some explorers reported can be explained by differences in the age, hibernation and feeding habits of the bear.

Equally bad is trichinosis, a parasitic disease contracted by eating the raw or undercooked flesh of pigs or wild game, including bear. Symptoms can include fever, muscle pain and fatigue, as well as inflammation of the heart muscle, lungs or brain, which have led to a few deaths.

Native peoples avoided polar bear liver because of its vitamin A concentration, and, like explorers and whalers, fed it only to their dogs. Modern Inuit and Inupiat value the flavor nuances of different bears or parts of a bear. Some prefer den polar bears, instead of bears caught in the open, because they taste better. The Cree consider the front and back paws (tukiq) the best eating.