My mother has told me that if your body needs a certain vitamin, you will find you feel like eating fruits that include that vitamin.
For example, if you have lack of Vitamin C, you'll get a craving to eat an orange.
Is this true?
Ok, this would appear to be supported.
Some of the papers I link will be about rats, some about humans because it's unethical to intentionally starve humans of vitamins.
Compulsive eating habits are a known symptom of vitamin deficiencies. For example patients suffering iron deficiency have been known to crave raw potatoes(high in iron), a craving which goes away after therapy with iron sulfate.
When rats are deficient in Vitamin B1 they have been shown to be able to detect solutions containing it from among a number of other solutions in similar containers and they then drink a lot of it.
Sodium deficient rats show a specific preference for the taste of sodium salt over other salts.
Though there is some evidence that in some cases deficiencies can induce a more general novel-diet preference: ie you get the urge to eat lots of weird things on the off chance that one of them will contain what your body needs.