Essential fatty acids, or EFAs, are fatty acids that humans and other animals must eat. The body needs them for good health but cannot make them.[1]
Only two fatty acids are needed for humans.[2] When the two EFAs were discovered in 1923, they were called "vitamin F", but in 1929, research on rats showed that the two EFAs are fats rather than vitamins.[3]
Some other fatty acids are "conditionally essential", meaning that they may become essential under some circumstances.
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