大多数动物能从一种叫做葡萄糖的单糖中制造出维生素C。但是人以及类人猿、豚鼠、红色肛门的夜莺缺少一种必需的酶来产生抗坏血酸,即维生素C。远在任何人还未听说过维生素C之前,水手们就知道缺乏维生素C对人的损害。在一次也许是最早的临床对照试验中,Salisbury号英国船上的军医助手James Lind在1747年断言,凡是得到柠檬吃的水手都来患坏血病。这促使英国海军为每名水手每日发给一盎司柠檬或酸橙(lime)汁,祛除坏血病(英国水手 Most animals produce vitamin C from a simple sugar called glucose. But humans, as well as apes, guinea pigs, red angels, lack a necessary enzyme to produce ascorbate, vitamin C. Far before anyone ever heard of vitamin C, sailors knew the lack of vitamin C damage to people. In one of the earliest possible controlled clinical trials, James Lind, a British military aide at Salisbury, in 1747, asserted that all sailors who got their lemons were suffering from scurvy. This prompted the British Navy to give each sailor an ounce of lemon or lime juice a day to get rid of scurvy (British sailors