Histamine

Histamine is a compound involved in local immune responses, regulates the gut, and acts as a neurotransmitter.

Role of histamine in the body
Histamine causes the release of nitric oxide, which in turn causes vasodilation.

Modulating histamine levels
Histamine is broken down by an enzyme called diamine oxidase (DAO), which is found mainly in the gastrointestinal tract and the placenta. Nutritional deficiencies in magnesium, Vitamin B6 and copper can decrease DAO activity.

Vitamin C reduces blood histamine levels.

Manganese and zinc can prevent the release of histamine from mast cells.

Histamine intolerance
Histamine intolerance can be a sign of mast cell activation disorder.