My husband had a blood test to cheeck calcium levels 6 months ago it was low and told to use caltrate plus now dr said to stop cause it's to high why?

Get a consult: You don't treat a lab value. Reference ranges are set so that a few % of healthies fall outside. A true low serum calcium in an adult who appears healthy is uncommon (calculate ionized calcium, which is what matters, based on albumin), and possible hypoparathyroidism or renal calcium wasting should be worked up. I trust vitamin d levels have been checked. Endocrinology consult is in order.