Which tests measure 25-Hydroxyvitamin D, Total (D2 + D3)?

25-Hydroxyvitamin D, Total (D2 + D3) is measured in 1 test on BiomarkersLabs.com, including Vitamin D, 25-Hydroxy, Total (Immunoassay) Test.

Biomarker Reference · 25-OH-D

What does the 25-Hydroxyvitamin D, Total (D2 + D3) test measure?

Q: Why is 25-Hydroxyvitamin D, Total (D2 + D3) measured?

Total 25-OH vitamin D, capturing both D2 and D3, is the standard index of vitamin D adequacy and reflects combined dietary, supplemental, and sun-derived sources. It is used to diagnose deficiency and insufficiency, guide and monitor supplementation, and investigate disorders of bone and calcium metabolism. The active metabolite calcitriol (1,25-OH vitamin D) is not used to assess status because its short half-life and tight regulation make it an unreliable measure of stores.

Q: What is the reference range for 25-Hydroxyvitamin D, Total (D2 + D3)?

The standard reference range for 25-Hydroxyvitamin D, Total (D2 + D3) is Sufficiency: 30–100 ng/mL (75–250 nmol/L); insufficiency: 20–29 ng/mL (50–74 nmol/L); deficiency: <20 ng/mL (<50 nmol/L) # REVIEWER FLAG: Sufficiency threshold is contested — Endocrine Society uses 30 ng/mL while the Institute of Medicine uses 20 ng/mL. Reviewer to confirm the threshold framing adopted by BiomarkersLabs.com.. Reference ranges vary by laboratory and assay platform — interpret in context of the issuing laboratory's stated range.

25-Hydroxyvitamin D, Total (D2 + D3) (25-OH-D) is a clinical biomarker used in vitamins-minerals assessment. 25-Hydroxyvitamin D is the major circulating form of vitamin D and the recommended marker of vitamin D status. It is measured in 1 laboratory test on BiomarkersLabs.com.

Reference Range: Sufficiency: 30–100 ng/mL (75–250 nmol/L); insufficiency: 20–29 ng/mL (50–74 nmol/L); deficiency: <20 ng/mL (<50 nmol/L) # REVIEWER FLAG: Sufficiency threshold is contested — Endocrine Society uses 30 ng/mL while the Institute of Medicine uses 20 ng/mL. Reviewer to confirm the threshold framing adopted by BiomarkersLabs.com.
Units: ng/mL, nmol/L
Measured In: 1 test
Category: Vitamins & Minerals

Functional medicine optimal40–60 ng/mL (functional medicine optimal range) # REVIEWER FLAG: Functional-medicine optimal range exceeds mainstream sufficiency thresholds — reviewer to confirm against IFM or equivalent source.

What is 25-Hydroxyvitamin D, Total (D2 + D3)?

25-Hydroxyvitamin D is the major circulating form of vitamin D and the recommended marker of vitamin D status. It is generated by hepatic 25-hydroxylation of vitamin D3 (cholecalciferol, from cutaneous synthesis and animal sources) and vitamin D2 (ergocalciferol, from plant and supplement sources). It circulates bound predominantly to vitamin D-binding protein with a half-life of approximately two to three weeks, making it a stable integrated measure of supply. It is the substrate for renal 1-alpha-hydroxylation to the active hormone calcitriol.

Why is 25-Hydroxyvitamin D, Total (D2 + D3) measured?

Total 25-OH vitamin D, capturing both D2 and D3, is the standard index of vitamin D adequacy and reflects combined dietary, supplemental, and sun-derived sources. It is used to diagnose deficiency and insufficiency, guide and monitor supplementation, and investigate disorders of bone and calcium metabolism. The active metabolite calcitriol (1,25-OH vitamin D) is not used to assess status because its short half-life and tight regulation make it an unreliable measure of stores.

Reference ranges

Standard reference: Sufficiency: 30–100 ng/mL (75–250 nmol/L); insufficiency: 20–29 ng/mL (50–74 nmol/L); deficiency: <20 ng/mL (<50 nmol/L) # REVIEWER FLAG: Sufficiency threshold is contested — Endocrine Society uses 30 ng/mL while the Institute of Medicine uses 20 ng/mL. Reviewer to confirm the threshold framing adopted by BiomarkersLabs.com.
Functional medicine optimal: 40–60 ng/mL (functional medicine optimal range) # REVIEWER FLAG: Functional-medicine optimal range exceeds mainstream sufficiency thresholds — reviewer to confirm against IFM or equivalent source.
Units: ng/mL, nmol/L

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

Tests that measure 25-Hydroxyvitamin D, Total (D2 + D3)

1 test on BiomarkersLabs.com include this biomarker.

BML-VIT-020Comprehensive

Vitamin D, 25-Hydroxy, Total (Immunoassay) Test

25-Hydroxyvitamin D, Total (D2 + D3) reference range in this test: Sufficiency: 30–100 ng/mL (75–250 nmol/L); insufficiency: 20–29 ng/mL (50–74 nmol/L); deficiency: <20 ng/mL (<50 nmol/L) # REVIEWER FLAG: Sufficiency threshold is contested — Endocrine Society uses 30 ng/mL while the Institute of Medicine uses 20 ng/mL. Reviewer to confirm the threshold framing adopted by BiomarkersLabs.com.

Related clinical conditions

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