Quick answer: Parathyroid hormone (PTH) is made by four small glands in the neck and keeps blood calcium in a tight range by acting on bones, kidneys and vitamin D. PTH is always interpreted with calcium and vitamin D. High PTH with high calcium suggests hyperparathyroidism; high PTH with low vitamin D is common and affects bone health.
Key takeaways
Parathyroid hormone keeps blood calcium in a tight range by acting on bones, kidneys and vitamin D.
It is always interpreted alongside calcium and vitamin D, because the combination tells the story.
A high PTH with high calcium suggests hyperparathyroidism, while a high PTH with low vitamin D is common and affects bone health.
What is PTH?
PTH is released by the parathyroid glands when blood calcium falls. It pulls calcium from bone, reduces calcium loss in urine and activates vitamin D to absorb more calcium from food.
Why PTH matters
PTH matters for calcium balance, bone remodeling, vitamin D activation, and nerve and muscle function.
Understanding your result
Reference ranges vary by lab, age and sex. Your provider interprets your result against the lab’s range and your overall picture, rather than chasing a single number. Functional labs are optional. They can be helpful in more complex cases.
What low PTH can mean
Low PTH can mean damage or removal of the parathyroid glands (for example, after neck surgery), low magnesium, or high calcium from other causes.
What high PTH can mean
High PTH can mean primary hyperparathyroidism (often with high calcium), low vitamin D or low calcium intake (secondary), or kidney disease.
What affects PTH
PTH is affected by vitamin D status, calcium intake, magnesium, and kidney function.
Ways to support healthy levels
Check and correct vitamin D (see vitamin D test), and get calcium from food such as dairy, sardines and leafy greens. Support your bones with strength training (see osteoporosis protection). High calcium with high PTH needs a medical evaluation.
What does the research show about parathyroid hormone?
The Uppsala Longitudinal Study of Adult Men followed 958 men with an average age of 71 for a median of 9.7 years, during which 117 died of heart-related causes. Each standard-deviation increase in PTH was linked with a 38% higher risk of cardiovascular death (hazard ratio 1.38), even among men with normal PTH, calcium, kidney function and vitamin D. The study included only older Swedish men and measured PTH once, so it shows an association rather than cause. (Hagström et al., 2009)
In the SWAN study of 2,311 women in the menopausal transition, spine bone density fell by 5.6% over 4 years in women who reached natural menopause, which shows why calcium-regulating hormones such as PTH and estrogen are often reviewed together. This study did not measure PTH directly, so it provides context about bone loss rather than evidence about PTH itself. (Sowers et al., 2006)
PTH is almost always interpreted with calcium, vitamin D and kidney function, and the research on PTH in people without parathyroid disease is still developing.
PTH and healthy aging
Persistently high PTH can pull calcium from bone and is linked with bone loss. Balanced PTH, calcium and vitamin D support healthy bone renewal.
When to see a naturopathic doctor
It may be time to see a naturopathic doctor if you have abnormal calcium results or low vitamin D. The same is true if you have osteoporosis or fractures, or kidney stones.
See a medical provider promptly for confusion, severe weakness, muscle spasms, tingling around the mouth or extreme thirst.
PTH at a glance
| Topic | What the article explains |
|---|---|
| Why it matters | Calcium balance; bone remodeling; vitamin D activation; and nerve and muscle function |
| What can affect it | Vitamin D status; calcium intake; magnesium; and kidney function |
| Supportive habits discussed | Check and correct vitamin D; get calcium from food such as dairy, sardines and leafy greens; and high calcium with high PTH needs a medical evaluation |
Questions to bring to your clinician
These questions can help you get the most out of your next visit.
Should we check my calcium and vitamin D together with my PTH result?
How should I read my PTH and calcium alongside the rest of my labs and my symptoms?
How often would it make sense to recheck my PTH and calcium in my situation?
Which daily habits or medications could be influencing my PTH and calcium before we retest?
Frequently asked questions
Why test PTH with calcium?
PTH only makes sense when read alongside calcium and vitamin D.
What does high PTH mean?
It can mean hyperparathyroidism or a response to low vitamin D or calcium.
Can vitamin D affect PTH?
Yes. Low vitamin D often raises PTH.
Does PTH affect bones?
Sources
- Bilezikian JP, et al. Guidelines for the management of asymptomatic primary hyperparathyroidism: summary statement from the Fourth International Workshop. J Clin Endocrinol Metab 2014. PMID: 25162665. https://pubmed.ncbi.nlm.nih.gov/25162665/
- Eastell R, et al. Diagnosis of asymptomatic primary hyperparathyroidism: proceedings of the Fourth International Workshop. J Clin Endocrinol Metab 2014. PMID: 25162666. https://pubmed.ncbi.nlm.nih.gov/25162666/
- Hagström E, et al. Plasma parathyroid hormone and the risk of cardiovascular mortality in the community. Circulation 2009. PMID: 19451355. https://pubmed.ncbi.nlm.nih.gov/19451355/
- Holick MF. Vitamin D deficiency. N Engl J Med 2007. PMID: 17634462. https://pubmed.ncbi.nlm.nih.gov/17634462/
- Sowers MR, et al. Hormone predictors of bone mineral density changes during the menopausal transition. J Clin Endocrinol Metab 2006. PMID: 16403818. https://pubmed.ncbi.nlm.nih.gov/16403818/
- MedlinePlus: Parathyroid Hormone (PTH) Test
- MedlinePlus: Parathyroid Disorders
This article is for educational purposes only and is not medical advice. It does not replace an individual evaluation. Talk with your healthcare provider before starting supplements or changing medications, especially if you are pregnant, nursing, or managing a health condition.
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