Normal PTH levels for Korean adults range from 17.3 to 53.6 pg/mL using the Roche Elecsys test, according to a 2026 study of 509 Korean adults. Gram Research analysis shows that vitamin D status significantly affects PTH interpretation—people with vitamin D deficiency (below 20 ng/mL) have substantially higher PTH levels than those with adequate vitamin D, which doctors should consider when evaluating results.
Researchers studied 509 Korean adults to figure out what normal parathyroid hormone (PTH) levels should be when using a specific lab test called the Roche Elecsys assay. PTH is a hormone that helps control calcium and bone health. The study found that normal PTH ranges from about 17 to 54 pg/mL for healthy people, though vitamin D levels can affect these numbers. This research helps doctors know when PTH results are truly abnormal versus just normal variation, which is especially important for diagnosing bone and kidney problems.
Key Statistics
A 2026 study of 509 Korean adults found that normal PTH levels range from 17.3 to 53.6 pg/mL using the Roche Elecsys assay, with no significant differences between men and women or across age groups.
Among 449 healthy Korean adults, individuals with vitamin D deficiency (less than 20 ng/mL) had significantly higher PTH concentrations compared to those with sufficient vitamin D levels (30 ng/mL or higher), according to the 2026 research.
The 2026 Korean PTH reference study confirmed that the upper limit of normal PTH tends to be higher in vitamin D-deficient subjects, suggesting vitamin D status should be considered when interpreting PTH test results.
The Quick Take
- What they studied: What are the normal ranges for PTH (a hormone that controls calcium) in Korean adults using a specific lab test?
- Who participated: 509 Korean adults (408 women and 101 men) with an average age of 44 years, tested between 2020 and 2023
- Key finding: Normal PTH levels range from 17.3 to 53.6 pg/mL in healthy Korean adults, though vitamin D status significantly affects these numbers
- What it means for you: If you get a PTH blood test in Korea, doctors now have better guidelines to tell if your result is normal or abnormal. However, your vitamin D level matters—people with low vitamin D tend to have higher PTH, which is important for doctors to know when interpreting results.
The Research Details
Researchers looked back at blood test results from 509 Korean adults collected over four years (2020-2023). They measured PTH levels and related markers like calcium, phosphorus, and vitamin D. They used a statistical method called CLSI EP28 to figure out what the normal range should be. First, they looked at everyone’s results, then they focused only on people with completely normal blood chemistry to get a more accurate picture of what ’normal’ really means.
The researchers also looked at how vitamin D status affected PTH levels. They divided people into groups based on their vitamin D levels: deficient (less than 20 ng/mL), insufficient (20-29 ng/mL), and sufficient (30 ng/mL or higher). This helped them understand whether vitamin D changes how we should interpret PTH results.
Every lab test needs a ’normal range’ so doctors know when something is wrong. But these ranges can be different depending on the population being tested and the specific lab equipment used. This study is important because it creates accurate normal ranges specifically for Korean adults using the Roche Elecsys machine, which is commonly used in Korean hospitals. Without this information, doctors might misinterpret results and give unnecessary treatment or miss real problems.
This study is reliable because it used a large sample (509 people), followed strict statistical methods recommended by clinical laboratory standards, and carefully excluded people with abnormal results to establish true ’normal’ ranges. The researchers also looked at vitamin D status, which shows they understood factors that could affect the results. The main limitation is that most participants were women (408 out of 509), so the results might not be equally accurate for men. Additionally, the study only looked at one specific lab test machine, so results might differ slightly with other equipment.
What the Results Show
The study found that normal PTH levels in Korean adults range from 17.3 to 53.6 pg/mL when using the Roche Elecsys test. This range was established by looking at 449 healthy adults with completely normal blood chemistry. Interestingly, the researchers found no significant differences between men and women, and age didn’t matter either—whether someone was 30 or 60 years old, the normal range stayed the same.
One important discovery was that vitamin D status dramatically affects PTH levels. People with vitamin D deficiency (less than 20 ng/mL) had significantly higher PTH levels compared to people with adequate vitamin D (30 ng/mL or higher). This makes biological sense because PTH helps regulate calcium, and vitamin D is needed to absorb calcium from food. When vitamin D is low, the body produces more PTH to try to maintain calcium balance.
The new reference intervals were very similar to what the test manufacturer originally suggested, which is reassuring. However, the upper limit (the highest normal value) tended to be higher in people with vitamin D deficiency, suggesting that vitamin D status should be considered when interpreting PTH results.
The study confirmed that the Roche Elecsys assay works consistently across the Korean population. When researchers looked at all 509 people (including those with some abnormal results), the PTH range was slightly wider: 16.7 to 64.2 pg/mL. This wider range shows why it’s important to exclude people with known health problems when establishing normal ranges—otherwise, the ’normal’ range becomes too broad and less useful for doctors.
This research aligns with international studies showing that PTH reference intervals are relatively consistent across different populations, though vitamin D status remains a key variable. The findings support what other researchers have discovered: that vitamin D deficiency is a major factor affecting PTH interpretation. The study validates the manufacturer’s suggested ranges while providing Korean-specific data, which is important because some studies suggest there may be ethnic variations in how bodies handle PTH and vitamin D.
The study has several limitations worth noting. First, about 80% of participants were women, so the results may not be equally accurate for men, though the researchers found no gender differences in this population. Second, the study only included people who had blood tests at one hospital system, so results might not represent all Korean adults. Third, the study didn’t look at seasonal variations in vitamin D, which can affect PTH levels. Finally, this research only applies to the Roche Elecsys test—other lab machines might give slightly different normal ranges.
The Bottom Line
According to Gram Research analysis, if you’re a Korean adult getting a PTH test with the Roche Elecsys machine, your result should fall between 17.3 and 53.6 pg/mL to be considered normal (high confidence). However, your doctor should also check your vitamin D level when interpreting PTH results, as low vitamin D can raise PTH even when it’s not a sign of disease (high confidence). If your PTH is high but your vitamin D is low, addressing the vitamin D deficiency may be the first step rather than assuming a PTH problem.
This research matters most for people in Korea getting PTH tests, especially those being evaluated for bone disease, kidney problems, or calcium disorders. Doctors and lab technicians in Korean hospitals should use these guidelines when interpreting PTH results. People with known vitamin D deficiency should be especially aware that their PTH might be higher than average without indicating disease. This research is less directly applicable to people outside Korea or those using different lab equipment, though the principles about vitamin D’s effect on PTH are universal.
PTH levels can change relatively quickly—within weeks to months—if vitamin D status improves. If you have low vitamin D and high PTH, you might see PTH levels normalize within 2-3 months of vitamin D supplementation. However, changes in PTH don’t always mean immediate changes in how you feel; the benefit is mainly that doctors can more accurately diagnose and monitor bone and kidney health.
Frequently Asked Questions
What is a normal PTH level for Korean adults?
Normal PTH levels for Korean adults range from 17.3 to 53.6 pg/mL using the Roche Elecsys test. However, vitamin D status affects these levels—people with low vitamin D may have higher PTH even when it’s not abnormal, so doctors should check vitamin D alongside PTH.
Does vitamin D affect PTH test results?
Yes, significantly. A 2026 study found that people with vitamin D deficiency (below 20 ng/mL) have substantially higher PTH levels than those with adequate vitamin D (30 ng/mL or higher). This is why doctors should always consider vitamin D status when interpreting PTH results.
Are PTH normal ranges different for men and women?
No, according to the 2026 Korean study of 509 adults, there were no significant differences in normal PTH ranges between men and women. The same reference interval (17.3-53.6 pg/mL) applies to both genders.
How long does it take to normalize PTH if I have low vitamin D?
PTH levels may begin to normalize within 2-3 months of correcting vitamin D deficiency through supplementation or increased intake. However, individual responses vary, and your doctor should retest PTH and vitamin D to confirm improvement.
Does age affect normal PTH levels?
No, the 2026 research found no significant age-related differences in normal PTH ranges for Korean adults. The same reference interval applies whether you’re 30 or 60 years old, though vitamin D status remains important for interpretation.
Want to Apply This Research?
- Log your PTH and vitamin D test results when you receive them, noting the date and lab facility. Track these values every 6-12 months if you have a history of abnormal levels, and note any vitamin D supplementation you’re taking.
- If your PTH is elevated, use the app to set reminders for vitamin D supplementation (if recommended by your doctor) and track your vitamin D intake through food and supplements. Set a reminder to retest PTH and vitamin D levels 2-3 months after starting supplementation to see if levels improve.
- Create a long-term tracking dashboard showing PTH and vitamin D trends over time. Set alerts if PTH falls outside the 17.3-53.6 pg/mL range, and correlate changes with vitamin D status and supplementation to help you and your doctor identify patterns.
This research provides laboratory reference intervals for PTH testing in Korean adults and should not be used for self-diagnosis. PTH results must be interpreted by a qualified healthcare provider in the context of your complete medical history, symptoms, and other blood tests. If you have concerns about your PTH or vitamin D levels, consult your doctor rather than relying solely on these reference ranges. This information is educational and does not replace professional medical advice, diagnosis, or treatment.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.