PTH and Vitamin D - many studies
The decrease in PTH (Parathyroid Hormone) is a good (only?) indicator that Vitamin D is actually getting into the cells
43+ VitaminDWiki pages have PTH or PARATHYROID in the title
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VitaminDWiki - Need 40 ng of vitamin D to have proper PTH levels – May 2011
What is the difference between the Intact Parathyroid Hormone and the Parathyroid Hormone (asked AI)
The difference between Intact Parathyroid Hormone (iPTH) and Parathyroid Hormone (PTH) primarily lies in the specific forms of the hormone that each assay measures and their clinical utility.
Intact Parathyroid Hormone (iPTH)
The iPTH assay measures the level of 1-84 PTH, which is the full, active form of the hormone, along with large truncated fragments of non-1-84 PTH, including 7-84 PTH. This assay is widely used, especially in the context of managing patients with chronic kidney disease, including those on dialysis, to assess parathyroid function and secondary hyperparathyroidism. The iPTH assay is considered the standard measurement for PTH in clinical practice and is used for approximately 90% of Japanese dialysis patients 1.
Parathyroid Hormone (PTH)
When referring to PTH without specifying "intact," it generally encompasses the entire spectrum of PTH forms, including both the active form and various inactive fragments. However, the term "whole PTH" specifically refers to assays that measure only the 1-84 PTH molecule without the inactive fragments. The whole PTH assay is more specific for the active form of the hormone and may provide a more accurate reflection of parathyroid function in certain clinical scenarios 1 .
Key Differences and Clinical Implications
Assay Specificity: The iPTH assay measures both the active form of PTH (1-84) and its large truncated fragments (e.g., 7-84 PTH), whereas the whole PTH assay specifically measures only the 1-84 PTH molecule 1.
Clinical Utility : The iPTH assay is widely used in managing patients with chronic kidney disease and secondary hyperparathyroidism. It has a high correlation with non-1-84 PTH fragments, which can be significant in certain patient populations. On the other hand, the whole PTH assay, by focusing solely on the active form of the hormone, may offer a more precise evaluation of parathyroid function in specific contexts 1.
Interpretation and Misclassification: Studies have shown that there can be significant differences in the classification of parathyroid hormone status between the iPTH and whole PTH assays, with a portion of patients potentially being misclassified into different guideline categories based on the assay used. This highlights the importance of assay selection in the accurate diagnosis and management of parathyroid-related disorders 1.
In summary, while both iPTH and PTH assays are used to evaluate parathyroid function and manage related disorders, they differ in their specificity and the forms of PTH they measure. The choice between these assays depends on the clinical context, with the iPTH assay being more commonly used in practice due to its broader measurement of PTH forms, including both active and inactive fragments 1.
Details, hyperlinks, images, etc. are at Perplexity Feb 2024