Vitamin A increases cold tolerance in goldfish.

As body stores of vitamin A, represented in the liver, are high in cold adapted animals, we hypothesized this phenomenon confers a survival value by increasing tolerance to cold. We injected retinol palmitate into goldfishes and found they tolerated cooler temperatures (4.6 degrees C more) and survived longer at 0 degree C (43 min 50% survival rate) compared to controls (28 min 50% survival rate). The resistance to cold is associated with the appearance of hepatic antifreeze protein(s) in the injected fishes.