Ammonia is generated as a byproduct of normal metabolism. The main way to control how much is made is by controlling total protein consumption. Ammonia is toxic, and so there are many ways of detoxing it. High ammonia can show up in a blood test.
Reasons to Suspect
MSG sensitivity, high protein diet, low folate diet, more.
Ammonia is created in the processing of protein foods. To reduce ammonia, don't eat too much protein. Those amino acids are really important, though, so make sure you're getting *enough* and choose your sources wisesly. For me, I'm translating this to a goal of getting the RDA (or slightly less) of protein, primarily from nutrient-dense animal sources like shellfish and liver.
Ammonia is detoxed by BH4, and by combining with alpha-ketoglutarate to form glutamate in the brain. Biotin and carnitine are supposed to help with ammonia toxicity.