Minerals Parathyroid glands

Parathyroid Hormone (PTH)

Written by the VitaWhat editorial team · Medically reviewed by Steve Davis · Last reviewed 19 July 2026 · Editorial policy

The main controller of calcium levels in the blood.

What it does

  • Raises blood calcium by acting on bone, kidney and gut
  • Balances phosphate

Too much

  • Too much (hyperparathyroidism) weakens bones and raises blood calcium (kidney stones, fatigue)

Too little

  • Too little lowers calcium, causing tingling and muscle cramps
Keeping it balanced: Adequate vitamin D and calcium support normal PTH function.

Sources & references

  1. You and Your Hormones (Society for Endocrinology)
  2. NHS — Hormonal conditions

Think a hormone may be out of balance?

The symptoms of hormonal excess and deficiency are non-specific — tiredness, weight change, low mood and poor sleep have many everyday causes. No hormone problem can be self-diagnosed from a symptom list.

Diagnosis needs blood tests interpreted alongside your history, sometimes repeated at set times of day because many hormones vary hour to hour. Speak to a GP if symptoms are persistent; seek urgent care for severe symptoms such as confusion, fainting, chest pain or extreme thirst with frequent urination.

Related entries

CalcitoninAdrenaline (Epinephrine)AldosteroneCortisolDopamineErythropoietin (EPO)
VitaWhat is an educational reference only. It is not medical advice and is not authoritative. Always consult a qualified healthcare professional before making changes to your diet, supplements or treatment. See how this content is produced in our editorial policy; report an error via the contact page.