What is the reference range for 1,25-Dihydroxyvitamin D?

The standard reference range for 1,25-Dihydroxyvitamin D is Approximately 18–72 pg/mL (43–172 pmol/L); assay- and laboratory-specific.. Reference ranges vary by laboratory and assay platform — interpret in context of the issuing laboratory's stated range.

Which tests measure 1,25-Dihydroxyvitamin D?

1,25-Dihydroxyvitamin D is measured in 2 tests on BiomarkersLabs.com, including Calcitriol (1,25 di-OH Vitamin D), Calcitriol 1,25-Dihydroxyvitamin D.

Biomarker Reference · 1,25(OH)₂D

What does the 1,25-Dihydroxyvitamin D test measure?

1,25-Dihydroxyvitamin D (1,25(OH)₂D) is a clinical biomarker used in vitamins-minerals assessment. Calcitriol is the hormonally active form of vitamin D, synthesised in the renal tubules by 1α-hydroxylase from 25-hydroxyvitamin D. It is measured in 2 laboratory tests on BiomarkersLabs.com.

Reference Range: Approximately 18–72 pg/mL (43–172 pmol/L); assay- and laboratory-specific.
Units: pg/mL, pmol/L
Measured In: 2 tests
Category: Vitamins & Minerals

Functional medicine optimalThere is no consensus 'optimal' calcitriol level for health; it is a diagnostic test interpreted in the context of calcium, phosphate, PTH, 25(OH)D, and clinical presentation rather than a screening or wellness marker.

What is 1,25-Dihydroxyvitamin D?

Calcitriol is the hormonally active form of vitamin D, synthesised in the renal tubules by 1α-hydroxylase from 25-hydroxyvitamin D. Its primary function is to maintain calcium and phosphate homoeostasis by increasing intestinal absorption of calcium, promoting renal calcium reabsorption, and mobilising calcium from bone in conjunction with parathyroid hormone. Calcitriol is tightly regulated by parathyroid hormone, fibroblast growth factor 23, calcium, and phosphate concentrations, and its circulating half-life is only a few hours. Serum calcitriol levels may be normal or even elevated despite vitamin D deficiency, because secondary hyperparathyroidism drives 1α-hydroxylase activity to sustain calcium absorption.

Why is 1,25-Dihydroxyvitamin D measured?

Calcitriol measurement is reserved for investigating disorders of vitamin D metabolism and calcium homeostasis, not for assessing vitamin D sufficiency. Elevated calcitriol is seen in granulomatous diseases (sarcoidosis, tuberculosis), some lymphomas, and primary hyperparathyroidism, while low calcitriol characterises chronic kidney disease, hypoparathyroidism, vitamin-D-dependent rickets, and hereditary phosphate-wasting disorders. Unlike 25-hydroxyvitamin D, calcitriol remains normal or even elevated in simple vitamin D deficiency because secondary hyperparathyroidism drives renal 1α-hydroxylase.

Reference ranges

Standard reference: Approximately 18–72 pg/mL (43–172 pmol/L); assay- and laboratory-specific.
Functional medicine optimal: There is no consensus 'optimal' calcitriol level for health; it is a diagnostic test interpreted in the context of calcium, phosphate, PTH, 25(OH)D, and clinical presentation rather than a screening or wellness marker.
Units: pg/mL, pmol/L

Reference ranges vary by laboratory and assay platform. Interpret in context of the issuing laboratory's stated range.

Tests that measure 1,25-Dihydroxyvitamin D

2 tests on BiomarkersLabs.com include this biomarker.

BML-VIT-026Comprehensive

Calcitriol (1,25 di-OH Vitamin D)

1,25-Dihydroxyvitamin D reference range in this test: Approximately 18–72 pg/mL (43–172 pmol/L); assay- and laboratory-specific.

BML-VIT-027Comprehensive

Calcitriol 1,25-Dihydroxyvitamin D

1,25-Dihydroxyvitamin D reference range in this test: Approximately 18–78 pg/mL (43–187 pmol/L), assay- and laboratory-specific.

Related clinical conditions

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