@Will L Actually that carrot story is a myth. It was part of an Allied Forces disinformation campaign to hide new radar technology from the Germans by spreading the rumor about carrots giving one night vision. It was a red herring.

You may be confusing the story with how in the 18th century, the British navy had forgotten the cure to scurvy (it was large amounts of vitamin C via lemons) and tried to eat carrots instead. Their skin became discolored.

All this information I found through this fine website at one point.