evidence: "CANCER HAS BEEN DEFEATED," declares a post on a Facebook page in Nigeria. "Cancer can be cured: Vitamin B17." [...] "Vitamin B17" is a name given to a substance called amygdalin, which is found in some nuts, seeds and plants. The US National Library of Medicine classifies it as an irritant. [...] ‘Vitamin B17’ isn’t a vitamin "Vitamin B17" is a name given to a substance called amygdalin, which is found in some nuts, seeds and plants. The US National Library of Medicine classifies it as an irritant.