glutathione free form vs reduced in plasma Redox State of and Cysteine Following Acute Stroke What is Glutathione? – GoldBio
Description
As long as your body can efficiently metabolize and break down histaminemainly through the enzyme called diamine oxidase (or DAO)having histamine is not only normal but also important for general health

Kidney or liver disease

Neurodegenerative diseases, including Alzheimers and Parkinsons, are also heavily influenced by oxidative stress, which accelerates the formation of harmful protein aggregates and neuroinflammation (Seo et al., 2023)

Hepatology 53 , 8695 (2011)

So if that protein is being attacked, B12 is not being absorbed
