The standardized uptake value (SUV) is a nuclear medicine term, used in positron emission tomography (PET) as well as in modern calibrated Single Photon Emission Tomography (SPECT) imaging for a (semi)quantitative analysis.[1] Its use is particularly common in the analysis of [18F]fluorodeoxyglucose ([18F]FDG) images of cancer patients.
As you know tums tablets are mainly made of calcium carbonate. To get calcium carbonate, mining or quarrying is required but pure calcium carbonate can be made from a pure quarried source such as marble, etc.
Tums provide calcium as calcium carbonate (chalk), which is not always easily absorbed by the body. I recommend using calcium citrate, a form that is better absorbed. Because Tums are less expensive than calcium supplements, you may prefer to risk the absorption problem in order to keep your costs down.