Vitamin D Assay - Serum

Most Vitamin D is stored in the body tissues as the 25-hydroxyvitamin D derivative (25-OH-D). The biologically active vitamin (1-alpha, 25-dihydroxyvitamin) D3 is produced locally in various tissues where it modulates calcium absorption and inflammatory responses. Total vitamin D nutritional status is indicated by serum (25-OH-D) measurement.

Why should you measure Vitamin D?

• Detect toxicity: You can take too much, leading to vascular calcification from hyperviatminosis D.
• Detect deficiency: Vitamin D regulates calcium and phosphorus absorption/resorption to maintain bone health.
  • Vitamin D deficiency and insufficiency were found quite prevalent in a recent study of subjects with osteopenia or osterporosis. Vitamin D deficiency was found among 33% of subjects below 50 years of age and 31.1% of subjects over 50 years of age. Vitamin D insufficiency was found among 35.9% of all subjects.**
  • Vitamin D insufficiency is linked to depression and Seasonal Affective Disorder.
• Vitamin D is important in neurological autoimmune processes like Multiple Sclerosis.
• Vitamin D upregulates apoptotic mechanisms in pro-inflammatory cells to arrest appropriately and preventing on-going inflammation that damages tissue.
• Recent studies have also linked low vitamin D levels with higher risk of heart attack, various cancers, and autoimmune diseases.

What form of Vitamin D are you measuring?

• Within hours, vitamin D from sunlight and diet is removed from circulation and recirculates again a few hours later as (25-OH-D). This form has the longest half life, about three weeks.
• (1, 25-OH)2D3)* is the more biologically active metabolite, but plasma concentrations are mainly dependent on renal function, appropriate parathyroid hormone levels, and the supply of calcium and phosphate. The levels of this metabolic decline only after vitamin depletion is virtually complete.

Vitamin D is also included in our ION Profiles!

*In various publications the term, "vitamin D3" has been used to identify the active form of vitamin D or its precursors.

**Vitamin D status in patients with osteopenia or osteoporosis - an audit of an endocrine clinic, " Kocjan T, Tan TM, et al, Int J Vitam Nutr Res, 2006; 76(5): 307-13

Test name(s)

0032 - Vitamin D Assay

Description

Most vitamin D is stored in body tissues as the 25-hydroxyvitamin D derivative (25OHD). The biologically active vitamin (1-alpha, 25-dihydroxyvitamin D3) is produced locally in various tissues where it modulates calcium absorption and inflammatory responses. Total body vitamin D nutritional status is indicated by serum 25OHD measurement.

Method

Chemiluminescence

Turnaround time

5-7 days, 6 days average

Analytes

25-Hydroxyvitamin D

Specimen Collection Instructions

• Fat-Soluble-Vitamins-KI.pdf

Sample Reports Example of how test results will be reported, including reference ranges and graphs indicating high and low percentiles of each analyte.

• Vitamin-D-SR.pdf

Interpretive Guides Information on individual analytes and possible patterns that may be indicated on your test results. Further supplement recommendations, diet modifications, and other treatment options may also be included to help guide your treatment.

• Fat-Soluble-Vitamins-IG.pdf

Patient Briefs

• Vitamin-D-PB.pdf

If you do not have the free Adobe Acrobat Reader, download it here.

Articles

• Vitamin D: A Clinical Perspective - Although its primary role is to regulate calcium and phosphorus absorption/resorption to maintain bone health, the clinical significance of vitamin D is very broad. This article explains why vitamin D is so important to the body.

Books

• Laboratory Evaluations for Integrative and Functional Medicine - Your evidence-based resource for the biochemical basis of chronic illness. A must-have desk reference for laboratory testing associated with nutritional and metabolic medicine.

Case Studies

• Mineral Testing and Osteoporosis - This is a case study involving a postmenopausal woman with osteoporosis. The case illustrates how whole blood minerals and toxic metals testing can give clues to causes of osteoporosis and help with supplement recommendations.

Podcasts

• Shedding a Little Sunlight on Vitamin D - There’s been a lot of talk about Vitamin D in the news lately. Clinical consultants, Dr. Elizabeth Redmond, and Dr. Eve Bralley, shed a little “sunlight” on today’s topic of Vitamin D.

Presentations

• IFM: The New Paradigm of Medicine - This PowerPoint presentation was developed by the Institute for Functional Medicine. It provides a concise explanation of the new paradigm of medicine that focuses on underlying causes of disease and treatment from that level rather treating symptoms alone, the approach often taken by modern medicine.

References

• Vitamin D References