histamine, b6 increase? or?

i was reading information about histamine intolerance and vit b6 many says vitamin b6 will increase diamine oxidase an enzym that breaks down histamine but i read some that says vit b6 synthesis histamine. isnt that gonna increase histamine instead? also citrus food are high histamine but it says vit c will help? also some says low copper could caused histamine intolerance/DOA defiency. could someone gives some inputs? thanks