Parathyroid Glands
The calcium regulators. Your four tiny parathyroid glands sit behind the thyroid and control blood calcium with exquisite precision. Parathyroid hormone (PTH) raises calcium when it drops. Critical for bones, nerves, and muscles. Dysfunction causes serious problems.
How Parathyroids Work
PTH Release
When calcium drops, PTH rises. Releases calcium from bones. Increases gut absorption.
Vitamin D Activation
PTH signals kidneys to activate vitamin D. 1,25-D boosts calcium absorption.
Kidney Retention
PTH reduces calcium excretion in urine. Holds onto calcium. Excretes phosphorus.
Parathyroid Problems
Hyperparathyroidism
Too much PTH. High calcium. Bone loss, kidney stones, fatigue. Usually adenoma.
Hypoparathyroidism
Too little PTH. Low calcium. Muscle cramps, tingling, seizures. Often post-surgery.
Secondary Hyperparathyroidism
Response to low D or kidney disease. PTH high but calcium normal/low.
Surgical Damage
Thyroid surgery can damage parathyroids. May need calcium supplementation.
Symptoms of High Ca
"Bones, stones, groans, moans." Bone pain, kidney stones, GI issues, fatigue.
Symptoms of Low Ca
Numbness, tingling, muscle spasms. Chvostek's sign. Can be severe.
Testing & Support
PTH Test
Intact PTH blood test. Compare to calcium level. Both matter together.
Calcium + D
Check calcium, ionized calcium, 25-OH-D. Full picture needed.
Optimize Vitamin D
Low D causes secondary hyperparathyroidism. Fix D first. PTH may normalize.