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.
It's active ingredient is calcium carbonate, just like Tums. In tums, each tablet has 500 mgs. The Children's Pepto has 400 mgs in each tablet (the dosage is 1 tablet for 2-5 year olds). Sooo.. there's not much of a difference between the two dosage wise, but I still think you should check with your doc.