When managing chronic kidney disease (CKD), phosphorus often gets a lot of attention. But there’s another lab that can offer early insight into how your body is really handling mineral balance—parathyroid hormone (PTH).
Even if your phosphorus level looks normal, your PTH might be quietly climbing.
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What Is PTH?
Parathyroid hormone (PTH) is a hormone made by your parathyroid glands, which are small glands located near your thyroid. Because of the similar name, many people think that parathyroid hormone is the same as your thyroid hormones, but they are quite different. Your thyroid hormones regulate your metabolism, while PTH helps regulate the levels of calcium and phosphorus in your blood.
When either calcium or phosphorus gets out of balance, your body releases more (or less) PTH to bring things back into range. It plays a key role in helping your bones, kidneys, and digestive system maintain stable mineral levels.
Why Does PTH Go Up in CKD?
As kidney function declines, your kidneys become less effective at removing phosphorus from the body and activating vitamin D (which helps you absorb calcium from food). This shift leads to lower calcium and higher phosphorus in the bloodstream—both of which trigger the release of more PTH.
So even if your phosphorus or calcium levels still look normal on a lab test, it may be staying that way only because your body is working harder—by producing more PTH.
Over time, this chronic overproduction of PTH is known as secondary hyperparathyroidism, and it’s very common in people with CKD.
What Are the Risks of High Parathyroid Hormone and CKD?
High levels of PTH can lead to a number of complications, especially if left untreated:
- Bone weakening – PTH signals the body to release calcium from the bones, which can lead to brittle or fragile bones over time. Fragility fractures occur 2-4x more frequently in people with CKD who have elevated PTH levels.
- Calcification of blood vessels – Elevated PTH can lead to calcification of the arteries, including the coronary arteries, which increases heart disease risk.
- Worsening mineral imbalance – PTH is part of a complex loop. As it rises, it can further disrupt the balance of calcium, phosphorus, and vitamin D in the body.
- Worsening Anemia – High PTH levels can affect the body’s ability to make healthy red blood cells, increasing the risk of anemia in people with CKD.
Even though high PTH is common in CKD, that doesn’t mean it’s harmless.
What Is Considered “High” PTH?
There’s no one-size-fits-all “ideal” PTH number for people with CKD, but for those who are not on dialysis, most professionals aim to keep PTH within the normal lab reference range—typically around 15–65 pg/mL.
That said, your care team will likely focus more on how your PTH is trending over time, rather than reacting to a single result. Fluctuations are common, and patterns give a clearer picture than one-off values.
How Often Should PTH Be Checked?
Monitoring depends on your stage of kidney disease. According to the 2017 KDIGO Guidelines, here’s how often PTH is typically checked:
- CKD Stage G3a–G3b: As needed, based on baseline values and progression
- CKD Stage G4: Every 6 to 12 months
- CKD Stage G5 (not on dialysis): Every 3 to 6 months
- Dialysis (G5D): Also every 3 to 6 months, though some providers monitor more frequently
Is PTH included with the Metabolic Panel or Complete Blood Count?
PTH is a separate lab and not included in a standard metabolic panel or complete blood count. The PTH lab is usually listed separately.
In my experience, parathyroid hormone is not always checked initially in individuals who have early stages of CKD or are newly diagnosed. If you have been diagnosed with CKD and not have this lab value, consider asking your healthcare provider to include it with your next set of labs.
Can you lower parathyroid hormone?
In the early stages of elevated parathyroid hormone, making changes to your diet and nutrition can often effectively lower PTH levels, while more advanced stages of secondary hyperparathyroidism could require medications or surgery to lower parathyroid levels and prevent complications.
The first step I recommend is to identify sources of phosphorus additives in your diet, and eliminate those whenever possible.
The sooner you intervene, the better your chances of lowering your PTH to a normal level and avoiding the consequences on your bones and cardiovascular system. If your PTH levels are elevated, we recommend working with a dietitian specializing in kidney disease to help you identify your risk factors for elevated parathyroid hormone.
Key Takeaways
Parathyroid hormone is a key part of how your body manages phosphorus and calcium, and it can reveal hidden stress long before your phosphorus lab ever looks abnormal. If you haven’t had your PTH checked recently—or ever—it might be time to ask about it.
Understanding what this hormone is doing behind the scenes can help you and your care team catch imbalances early and protect your bones, heart, and long-term kidney health.