Calcium isn't what causes hyperthyroidism; excess thyroid hormones cause hyperthyroidism. The parathyroids are related to calcium and most of us have 4 of them. I've never heard of them taking 3 and 3/4 of the parathyroids; typically, they don't take part of a parathyroid. They take the whole thing.
Have you had your thyroid removed? If so, you'd have to be taking replacement thyroid hormones, such as Synthroid, levothyroxine, etc. Calcium doesn't alleviate hypothyroidism, only thyroid hormones will help that.
If you can please clarify the medications you're taking, that would be most helpful...