From an article written by Thomas Levy, MD (cardiologist and lawyer):

"Calcium should never be supplemented in any amount, period. Dairy intake should be minimized. Virtually all older persons have excesses of calcium in their bodies. There is absolutely no danger of a generalized calcium deficiency existing in the body."

Link to the article:
https://www.tomlevymd.com/articles/nh20130727/Calcium-the-Toxic-Supplement/

He also has plenty of interesting information on supplement stacks. Several YouTube interviews.