Alkaline phosphatase is a family of membrane-associated hydrolase enzymes (isoenzymes) expressed in several tissues—most notably liver and bone, but also intestine, placenta, and kidney. Clinically, ALP has long been measured as a routine laboratory marker because its activity shifts with changes in bile flow and bone remodeling. Biochemically, ALP catalyzes dephosphorylation of organic phosphates at alkaline pH, a reaction involved in mineralization processes in bone and in transport across cell membranes in the biliary system. Different tissue isoforms can be separated in specialized labs to help localize the source of altered activity.

Elevated ALP activity may reflect increased bone formation (growth, remodeling, healing) or changes in biliary excretion and liver-related processes; it can also occur with pregnancy or certain systemic responses. In cardiovascular research, higher ALP levels are sometimes associated with vascular calcification and inflammatory patterns, but such links require consideration of other markers. Lower-than-expected ALP can be seen with low bone turnover states, some nutritional or mineral deficiencies (for example low zinc or magnesium), certain medications, or rare inherited patterns that reduce enzyme activity. Because ALP comes from multiple tissues, interpretation depends on complementary tests (GGT, bilirubin, calcium, phosphate, bone markers) and the full Cardio Zoomer profile.

Cardio Zoomer includes ALP to add liver–bone axis information to the cardiovascular picture. ALP helps distinguish whether altered lab patterns reflect biliary/liver processes versus bone activity and contributes to assessing metabolic and vascular risk patterns when combined with lipid, inflammatory, and endothelial markers.