To the Editor.—
Dr Jukes writes (234:806, 1975), "The argument about the 'slice of liver' is not persuasive; consumption of polar bear liver has caused vitamin A poisoning." This is the type of argument that should never be used. The "slice of liver" referred to by Dr Pauling is obviously the commonly consumed beef liver. A slice of beef liver (approximately 100 gm) contains 40,000 units of vitamin A. The same amount of polar bear liver contains 2 million units! I wonder how many of us are exposed to this danger.