What substance is NOT typically found in urine?

The substance that is typically not found in urine in significant amounts is glucose. Under normal physiological conditions, the kidneys reabsorb glucose in the proximal tubule, effectively preventing it from appearing in the urine. Therefore, healthy individuals should have negligible or undetectable levels of glucose in their urine.

In contrast, urea, creatinine, and uric acid are all normal constituents of urine. Urea is a waste product formed from the breakdown of proteins, creatinine is a byproduct of muscle metabolism, and uric acid is produced from the metabolism of purines. The appearance of glucose in urine, known as glucosuria, can indicate conditions such as diabetes mellitus, where the renal threshold for glucose reabsorption is surpassed. This is why glucose is the correct choice as the substance not typically found in urine under normal circumstances.