Most of us who don't eat dairy end up needing to supplement some. But Tums is just not the best form of supplement to take. Aside from it containing calcium carbonate which is probably the least absorbable form and needs to be taken with food (as citrate can be consumed any time), it is filled with artificial colorings and flavorings. Many of those colorings are derived from petroleum and some are suspected carcinogens. Many are banned in Europe but not by our FDA. Mineral oil is also derived from petroleum. Corn starch is geneticially modified and can cause blood sugar spikes, maybe not in the small quantity that the tablet contains but if you take it regularly, who knows, it's just not a healthy thing to consume. I think when we approach osteoporosis or any other illness, or just in our quest to promote health and maintain a healthy body, it's not a bad idea to consume the cleanest, healthiest foods and products out there.

For a deeper dive, here's a great analysis of studies conducted on food colorings/dyes from the Center for Science in the Public Interest.
https://www.cspinet.org/sites/default/files/attachment/food-dyes-rainbow-of-risks.pdf