I've often heard that the myth that eating carrots helps you see better at night (not to be confused with carrots helping with vitamin A deficiency) was started by the British in World War II, as propaganda to help conceal the fact that the RAF planes were equipped with radar. The story was that the RAF were able to find the German planes at night because their pilots were able to see very well in the dark due to eating a lot of carrots, and not because they were flying around with nifty gadgets.
The Smithsonian Magazine website summarized it:
During the 1940 Blitzkrieg [of Britain], the Luftwaffe often struck under the cover of darkness. In order to make it more difficult for the German planes to hit targets, the British government issued citywide blackouts. The Royal Air Force were able to repel the German fighters in part because of the development of a new, secret radar technology. The on-board Airborne Interception Radar (AI), first used by the RAF in 1939, had the ability to pinpoint enemy bombers before they reached the English Channel. But to keep that under wraps, according to Stolarczyk’s research pulled from the files of the Imperial War Museum, the Mass Observation Archive, and the UK National Archives, the Ministry provided another reason for their success: carrots.
Was this when the myth started? Or was the idea already out there in the public consciousness, and it was just exploited/popularized by the British Ministry of Information?
For example, were there popular writings from the '30s (newspapers, books, notable studies, etc) that were already making the leap from "vitamin A deficiency causes night blindness, so mega dosing vitamin A will enhance night vision", similar to the contemporary myth that "oxidants kill cells, so mega dosing antioxidants will keep you from aging"?