Thyroidectomy and Partial Parathyroidectomy

If a thyroid is determined to be small and friable, is that sufficient reason to remove it even though the TSH and T4 tests are within the normal range?
If one or two of the parathyroid glands are removed due to an adenoma, how long might it take for the remaining parathyroid glands to begin functioning?
Does taking large amounts of calcium and prescription strength Vitamin D inhibit the remaining parathyroid glands from "waking up"?
Does taking Synthroid have any effect on the parathyroid glands?
When going in for lab tests for TSH and T4, should one stop taking Synthroid the morning of?
When going in for calcium levels tests and PTH, should one stop taking calcium and Vitamin D the morning of?

Thanks,

Mary

[Mark Lupo, M.D.]

Synthroid does not impact parathyroid function and can be taken day of TSH testing.
PTH and Ca testing can be done on supplements unless directed otherwise by MD.
It takes a few days sometimes for normal parathyroids to wake up after removing adenoma(s) -- it depends on the severity of the case - may take a week or more in some cases.
Thyroid surgery is usually reserved only for cases of suspicious biopsy or compressive goiter/nodules -- so not for a small/friable gland.