First of all, “Does anyone eat a polar bear?” need to answer the question. In areas like Greenland there are indeed people who eat polar bear meat, but never their liver.
The odds of you eating both polar bear meat and liver are pretty low, but that’s not the point. How come eating a polar bear’s liver has such an effect that it kills you? Let’s explain this:
Polar bear meat that a family living in Greenland is preparing for dinner:
So why is it deadly to eat liver when it is possible to eat its meat? Because the liver of the polar bear contains too much vitamin A.
Polar bears are the best carnivores to bioaccumulate the vitamin A produced by seaweed.
Some vitamins are water soluble, while vitamin A is only fat soluble. Since it is insoluble in water, it cannot be easily excreted from the body through urine.
Instead, toxic nutrients are collected in the liver, the body’s filtration organ. This event leads to a state of hypervitaminosis.
Bears and seals usually have high levels of vitamin A in their livers, with polar bears on top.
The recommended daily intake (RDA) for vitamin A in humans is 0.9 mg.
You can get this amount by eating just one-tenth of a polar bear’s liver. Too much will kill you.
Whole polar bear liver contains enough vitamin A to kill 52 adults.
Let’s say you save the liver and eat your daily intake every day, in such a case that liver would be enough for you for 143 years. There is a total of 52,195 capsules of vitamin A in the liver of a polar bear.
Sources: 1, 2