What Does The Lab Parathyroid Hormone Tell You And Why Does D Lower It

[biggirlkisss]

what does the lab parathyroid hormone tell you and why does vitamin d and calcium lower it?

 

[Mito]

The parathyroid gland continuously monitors serum calcium. When it senses that serum calcium is too low, it releases more parathyroid hormone (PTH). PTH mobilizes calcium from bone into the blood.

Vitamins D is metabolized in the liver to 25-hydroxyvitamin D (25(OH)D). Then 25(OH)D is further metabolized to calcitriol (1,25 dihydroxyvitamin D) mostly in the kidneys. Calcitriol mobilizes calcium from the bones into the blood similar to PTH but unlike PTH it also increases calcium absorption from food.

So when we have enough vitamin D then we can make enough calcitriol. And when we have enough calcium in the diet, that calitriol can be used to increase the dietary calcium absorption which then increases serum calcium. When serum calcium increases the parathyroid hormone relaxes and secretes less PTH.

 

[biggirlkisss]

why does magnesium lower pth then? Helps absorb calcium better?

 

[Amazoniac]

- Differences in the function of parathyroid peptides. What are we measuring?
- PTH—A Particularly Tricky Hormone: Why Measure It at All in Kidney Patients?