Same with me. Script for 50,000 unit once a week. Get blood work done every 4 months. Last workup was 44.
My endocrinologist became my primary care doctor about 6-7 years ago when my family doctor left the state and moved south. I go for fasting bloodwork every six months before I see him. I'm due again in September. Many years ago my Gynecologist prescribed calcium tablets with Vitamin D. At some point, blood work revealed that I had very high levels of calcium in my system, and had to stop taking it. I was diagnosed with a hyper parathyroid, which I get tested for every six months. My calcium levels remain high, but my endocrinologist hasn't recommended surgery to remove it.