FBR Announces The Availability Of
25 (OH) Vitamin D Measurement
Background
Vitamin D has an important hormonal role in many aspects of human health.1 As sunlight exposure is necessary for vitamin D synthesis by the skin, populations living at northern latitudes (such as in Maine2,3) are at particular risk for deficiency (defined as a serum concentration <20 ng/mL) or insufficiency (<30 ng/mL).4,5 The best-known function of vitamin D is calcium homeostasis and severe vitamin D deficiency leads to secondary hyperparathyroidism, causing muscle weakness and rickets in children and osteomalacia in adults. Vitamin D may, however, impact a wide spectrum of other conditions, from mood disorders to cancer.4,6,7
In pregnancy, vitamin D deficiency has health consequences for both the mother and the fetus. For the mother, low vitamin D levels are associated with an increased risk for developing gestational diabetes mellitus8 and pre-eclampsia.9 For the fetus, as for children and adults, bone mass is reduced by vitamin D insufficiency10 and this effect extends far into childhood.11 Low maternal vitamin D levels also have an adverse effect on birthweight12 and are associated with increased rates of asthma among 5 year old children.13 Thus, identifying and treating pregnant women with vitamin D insufficiency could improve health outcomes for both mother and child.
In autoimmune disease, vitamin D's role is mediated through the adaptive and innate immune systems and an adequate supply appears to reduce the risk for developing diseases such as diabetes mellitus, rheumatoid arthritis, lupus, multiple sclerosis and inflammatory bowel disease.14,15 Low serum levels may be associated with increased disease activity in conditions such as rheumatoid arthritis,16 Sjögren's syndrome,17 and SLE.18 Furthermore, treatment with a vitamin D analog may improve clinical status in rheumatoid arthritis19 and help to prevent bone loss among patients taking corticosteroids.20
INDICATIONS FOR TESTING
- Clinical suspicion of vitamin D insufficiency or deficiency
- Conditions known to be associated with vitamin D deficiency (e.g. osteoporosis or osteopenia; renal disease; rheumatic disease; autoimmune disease)
- Other considerations: inadequate sunlight exposure and/or dietary intake; skin color
TECHNICAL INFORMATION
The Foundation for Blood Research measures total 25(OH) vitamin D (D2 plus D3) by radioimmunoassay. This FDA-approved assay, developed by Hollis et al.21 and manufactured by DiaSorin Inc. (Stillwater, MN), has been a standard in both clinical and research laboratories for over 15 years.5,22 FBR participates in the DEQAS (Vitamin D External Quality Assessment Scheme) proficiency testing programs.
ORDERING INFORMATION
TOTAL VITAMIN D MEASUREMENT
Total 25(OH) vitamin D3 (VITD) can be ordered by checking the appropriate box on either FBR's General Requisition or the Prenatal Screening Requisition. When using older versions of these forms, just write "vitamin D" or "VITD" in the "Other" box (General Requisition) or in the "Comment" box (Prenatal Screening Requisition).
Specimen: 1mL of non-lipemic, non-hemolyzed serum or plasma (EDTA or heparin). Fasting is recommended but not required.
Storage and shipping: Room temperature or 2-8C.
Turn around time: Contact for further information
Price: Contact for further information
CLIENT SUPPORT
Clinical information: contact , MD, Medical Director.
Technical information: contact , MS, , BA, Technical Supervisors, or , Ph.D., Senior Research Scientist.
General information: contact , MS, Director of Client Services.
References
1. Heaney RP. Am J Clin Nutr 2004;80(suppl): 1706S-9S.
2. Rosen CJ, et al., Bone Min 1994;25(2):83-92.
3. Sullivan SS, et al., J Am Diet Assoc 2005;105(6):971-4.
4. Holick MF. Vitamin D deficiency. NEJM 2007;357(3):266-81.
5. Hollis BW. J Nutr 2005;135:317-322.
6. Cantorna MT et al., Am J Clin Nutr 2004;80(suppl): 1717S-20S.
7. DeLuca HF. Am J Clin Nutr 2004;80 (suppl):1689S-96S.
8 Zhang C, et al. PLoS One USA 2008;3(11):e3753.
9. Haugen M, et al. Epidemiol 2009;20(5):720-6.
10. Mahon P, et al. J Bone Miner Res 2009; jul 6, e-pub ahead of print;
11. Javaid MK, et al. Lancet 2006;367:36-43.
12. Scholl TO, Chen X. Early Hum Dev 2009;85(4):231-4.
13. Erkkola M, et al. Clin Exp Allergy 2009;39(6):875-82.
14. Costenbader KH et al., Ann Rheum Dis 2008;67:530-5.
15. Szodoray P et al., Scand J Immunol 2008;68:261-9.
16. Oelzner P et al., Calcif Tissue Int 1998;62(3):193-8.
17. Bang A et al., Scand J Rheumatol 1999;28(3):180-3.
18. Borba VZ et al., Osteoporos Int 2009;20(3):427-33.
19. Andjelkovic Z et al., Clin Exp Rheum 1999;17:453-6.
20. Buckley LM et al., Ann Intern Med 1996;125:961-8.
Published in July, 2010