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Ammonia in serum
Medical expert of the article
Last reviewed: 04.07.2025
Ammonia is a product of protein metabolism, formed in all tissues. The largest amount of ammonia (80%) is formed inside the intestine under the influence of bacteria. Nitrogen compounds such as amino acids, uric acid, urea in the presence of bacterial enzymes (protease, urease, amine oxidase) are metabolized to ammonia. Ammonia is also formed in the cells of the intestinal mucosa from glutamine. Metabolism of ammonia to urea occurs in the liver during the ornithine cycle. This process can be disrupted both as a result of hyperproduction of ammonia in the intestine, and due to a decrease in its conversion to urea in liver pathology.
Reference values for serum ammonia (ammonia nitrogen) concentration
Age |
Serum ammonia concentration |
|
Mcg/dl |
µmol/l |
|
Newborns |
90-150 |
64-107 |
0-2 weeks |
79-129 |
56-92 |
Older than 1 month |
29-70 |
21-50 |
Adults |
15-45 |
11-32 |
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