1 interaction related to fit test
Vitamin C (ascorbic acid) is a reducing agent that can block the guaiac peroxidase color reaction used in traditional guaiac-based fecal occult blood tests (gFOBT, including Hemoccult). This can produce a falsely negative result even when gastrointestinal bleeding is present, potentially masking a bleeding source. Newer fecal immunochemical tests (FIT) use antibodies to detect human hemoglobin and are not affected.
