Hello Elizabeth,
Taking just calcium and vitamin D will get the calcium into the arteries, but only a little will reach the bones. We need vitamin K2 that is MK7 form. Otherwise, the calcium builds up in the arteries and causes calcification which can block the arteries.
Our ancestors had plenty of K2, but with today's methods of producing food, we get very little.
Below is a reference to K2 and why it is needed:

"It’s not enough to just take calcium; we need to aim it at the bones. If we take calcium willy-nilly without paying attention to where it goes, it will end up in our soft tissues, like arteries and joints, and the last place we want calcium is in soft tissues as it can increase risk for heart attacks, stroke and pain.

If you take calcium with vitamin D, you will absorb more of the calcium. That might seem like a good thing, but if you don’t have enough vitamin K2 on hand, the calcium will end up where you don’t want it.

Vitamin K2 activates a protein called matrix GLA which removes calcium from soft tissues and it also activates osteocalcin, which holds calcium to bone. So, if you have a lot of calcium, you need vitamin K2 to direct it."
https://blog.encompasshealth.com/2019/08/28/calcium-without-k2-is-a-heartbreaker/#:~:text=Vitamin%20K2%20activates%20a%20protein,not%20how%20much%20you%20have.