Sunday, August 2, 2015
Calcitriol and Calcium Supplements
I am hypocalcemic due to a complete thryoidectomy; as far as I know, I have 2 1/2 parathyroid glands remaining. My surgery was January 8. As of March 9, my serum calcium was 8.0; ionized calcium was 1.09; magnesium was 2.1; and PTH was 12.1. I am taking 2400 mg. calcium citrate and .25 mcg Calcitrio 3x daily.
Since the PTH measured 12.1, does this mean that the glands are functioning but on low levels? How long does it normally take for the parathyroid glands to fully "wake up" after surgery?
Could you tell me, please, whether Calcitriol and/or calcium supplements suppress the parathyroid glands?
Is ionized calcium a better indicator than serum calcium for calcium levels?
I very much appreciate answers to previous questions and hope you can shed more light.
"Since the PTH measured 12.1, does this mean that the glands are functioning but on low levels?" Yes
"How long does it normally take for the parathyroid glands to fully 'wake up' after surgery?" It is quite variable. It may take a few months, several years, or complete function may not come back at all.
"Could you tell me, please, whether Calcitriol and/or calcium supplements suppress the parathyroid glands?" Calcitriol and calcium supplements do not suppress the parathyroid glands unless they raise the serum calcium level too high. We usually aim for a slightly low serum calcium during replacement therapy - a total serum calcium of about 8.0 to 8.5. This insures that the parathyroids are stimulated to grow if they can.
"Is ionized calcium a better indicator than serum calcium for calcium levels?" The ionized calcium has been a bit of a tricky assay in the past, though I'm sure today's assays are very good. I personally am more comfortable using the serum total calcium as long as the serum albumin is normal. A low albumin can falsely lower the serum total calcium.
Thomas A Murphy, MD, FACP, FACE
Associate Professor of Medicine
School of Medicine
Case Western Reserve University