The thyroid-parathyroid glands have similar names but they produce different hormones with diverse roles within the body. Here’s what you need to know, including how to check parathyroid function with a simple blood test.
The primary role of the parathyroid glands is to produce parathyroid hormone (PTH). This hormone tightly regulates calcium and phosphate levels within the body and facilitates the synthesis of active vitamin D. You may already know optimal calcium balance keeps your bones strong, and this mineral is crucial for healthy muscle function and nervous system activity.
Where Are The Parathyroid Glands Located?
You have four parathyroid glands which are normally around the size of a pea. For most people there are two parathyroid glands attached on either side of the back of the thyroid.
‘Para’ means near which explains the name given to these tiny parathyroid glands which are closely situated to the thyroid. Interestingly these two glands share the same blood supply and is one of the reasons why it’s not uncommon to experience both a thyroid and parathyroid disorder.
If your thyroid has been removed it’s very likely your parathyroid glands were also removed BUT you need to check with your surgeon.
The Vitamin D – Parathyroid Connection
The link between vitamin D and bone health was made when researchers discovered sunlight, or taking cod liver oil boosted vitamin D. This in turn helped prevent a soft bone disorder in children called ‘rickets’.
Today, vitamin D research shows adequate D3 is vital to keep bones strong and healthy.
A drop in D3 is associated with higher production of parathyroid hormone. This has the potential to increase bone loss. It’s the reason maintenance of optimal D3 can help guard against excessive bone turnover.
How Do You Check Parathyroid Function?
It’s important to know the parathyroid hormone (PTH) blood test measures circulating levels of parathyroid hormone and is used to detect parathyroid gland dysfunction.
- Low parathyroid hormone levels –> reduced calcium uptake. It’s important to be aware the symptoms include tingling in the fingers and toes, muscle aches and spasms, fatigue, dry skin and brittle nails, headaches, anxiety, and depression.
- High parathyroid hormone levels –> calcium is dissolved from the bones which weakens the bones. This result puts you at greater risk of developing osteoporosis.
A check of parathyroid health should be done along with testing calcium and D3 levels within the blood. As these are fasting blood tests you are advised to avoiding eating or drinking fluids before testing.
Feeling concerned about parathyroid health? It’s vital to talk to your doctor about testing. To recap, there are 3 key tests you need to properly assess parathyroid function;
- Parathyroid hormone (PTH).
- Serum calcium.
- D3 (25-hydroxycholecalciferol).
Chaker L, Bianco AC, Jonklaas J, Peeters RP. Hypothyroidism. Lancet. 2017;390(10101):1550-1562. Link
Khan M, Jose A, Sharma S. Physiology, Parathyroid Hormone. [Updated 2021 Mar 21]. In: StatPearls. Treasure Island (FL): StatPearls Publishing; 2021 Jan. Link