Indications and risk factors

• Acne

• Breast-Fed Infants

• Cancer

• Cardiovascular disease

• Chronic low back pain

• Dark skin

• Depression

• Diabetes types 1 & 2

• Fibromyalgia

• Hyperinsulinemia

• Hypothyroidism

• Increased belly fat

• Multiple sclerosis

• Non-specific musculoskeletal pain

• Obesity

• Osteomalacia

• Osteoporosis

• Psoriasis

• Rheumatoid arthritis

• Schizophrenia

• Stroke

• The elderly

Analytes:

25-OH D2, 25-OH D3, Total

Practical

This test helps to monitor and identify vitamin D deficiency as a potential cause of health problems - levels below 32 ng/mL are thought to indicate deficiency (research is ongoing to establish definitive recommendations - some experts suggest that levels should be >50 ng/mL for optimal health). Deficiency may be present even when there are no symptoms, yet it is simple to correct and may solve a number of subclinical health problems and reduce risk for more serious diseases.

This test uses liquid chromatography/tandem mass spectrometry (LC-MS/MS) and it participates in DEQAS, the Vitamin D Quality Assessment Scheme, which provides control samples to ensure assay accuracy. Method accuracy is also ensured by standardization with the National Institute of Standards and Technology (NIST) Vitamin D standard reference materials.

Practical

Specimen requirements:

Dried bloodspot sample (DBS). (Only requires a shallow finger prick).

Average processing time:

11 ±4 days (Confidence: applies to 91% of tests)

Research

• Al Faraj S, Al Mutairi K. Vitamin D deficiency and chronic low back pain in Saudi Arabia. Spine. 2003;28(2):177-9.

• Armas LA, Hollis BW, Heaney RP. Vitamin D2 is much less effective than vitamin D3 in humans. J Clin Endocrinol Metab. 2004;89(11):5387-91.

• Bischoff-Ferrari HA, Willett WC, Wong JB, Giovannucci E, Dietrich T, Dawson-Hughes B. Fracture prevention with vitamin D supplementation: a meta-analysis of randomized controlled trials. JAMA. 2005;293(18):2257-64.

• Boonen S, Bischoff-Ferrari HA, Cooper C, Lips P, Ljunggren O, Meunier PJ,Reginster JY. Addressing the musculoskeletal components of fracture risk with calcium and vitamin D: a review of the evidence. Calcif Tissue Int. 2006;78(5):257-70.

• Cannell JJ, Vieth R, Willett W, et al. Cod liver oil, vitamin A toxicity, frequent respiratory infections, and the vitamin D deficiency epidemic. Ann Otol Rhinol Laryngol. 2008;117(11):864-70.

• Faiz S, Panunti B, Andrews S. The epidemic of vitamin D deficiency. J La State Med Soc. 2007;159(1):17-20; quiz 20, 55.

• Heaney RP. Vitamin D--the iceberg nutrient. J Musculoskelet Neuronal Interact. 2006;6(4):334-5.

• Holick MF. High prevalence of vitamin D inadequacy and implications for health. Mayo Clin Proc. 2006;81(3):353-73.

• Holick MF. Sunlight and vitamin D for bone health and prevention of autoimmune diseases, cancers, and cardiovascular disease. Am J Clin Nutr. 2004;80(6 Suppl):1678S-88S.

• Holick MF. The vitamin D epidemic and its health consequences. J Nutr. 2005;135(11):2739S-48S.

• Holick MF. Vitamin D deficiency. N Engl J Med. 2007;357(3):266-81.

• Holick MF. Vitamin D: important for prevention of osteoporosis, cardiovascular heart disease, type 1 diabetes, autoimmune diseases, and some cancers. South Med J. 2005;98(10):1024-7.

• Hollis BW, Wagner CL. Vitamin D requirements during lactation: high-dose maternal supplementation as therapy to prevent hypovitaminosis D for both the mother and the nursing infant. Am J Clin Nutr. 2004;80(6 Suppl):1752S-8S.

• Hollis BW. Circulating 25-hydroxyvitamin D levels indicative of vitamin D sufficiency: implications for establishing a new effective dietary intake recommendation for vitamin D. J Nutr. 2005;135(2):317-22.

• Houghton LA, Vieth R. The case against ergocalciferol (vitamin D2) as a vitamin supplement. Am J Clin Nutr. 2006;84(4):694-7.

• Lewis PJ. Vitamin D deficiency may have role in chronic low back pain. BMJ. 2005;331(7508):109.

• MacLaughlin J, Holick MF. Aging decreases the capacity of human skin to produce vitamin D3. J Clin Invest. 1985;76(4):1536-8.

• Need AG, Horowitz M, Morris HA, Nordin BC. Vitamin D status: effects on parathyroid hormone and 1, 25-dihydroxyvitamin D in postmenopausal women. Am J Clin Nutr. 2000;71(6):1577-81.

• Need AG, Morris HA, Horowitz M, Nordin C. Effects of skin thickness, age, body fat, and sunlight on serum 25-hydroxyvitamin D. Am J Clin Nutr. 1993;58(6):882-5.

• Newman MS, Brandon TR, Groves MN, Gregory WL, Kapur S, Zava DT. A Liquid Chromatography/Tandem Mass Spectrometry Method for Determination of 25-Hydroxy Vitamin D2 and 25-Hydroxy Vitamin D3 in Dried Blood Spots: A Potential Adjunct to Diabetes and Cardiometabolic Risk Screening. J Diabet Sci Technol 2009;3(1):156-162.

• Peterlik M, Cross HS. Vitamin D and calcium deficits predispose for multiple chronic diseases. Eur J Clin Invest. 2005;35(5):290-304.

• Plotnikoff GA, Quigley JM. Prevalence of severe hypovitaminosis D in patients with persistent, nonspecific musculoskeletal pain. Mayo Clin Proc. 2003;78(12):1463-70.

• Poole KE, Loveridge N, Barker PJ, Halsall DJ, Rose C, Reeve J, Warburton EA. Reduced vitamin D in acute stroke. Stroke. 2006;37(1):243-5.

• Rajakumar K. Vitamin D, cod-liver oil, sunlight, and rickets: a historical perspective. Pediatrics. 2003;112(2):e132-5.

• The EURODIAB Substudy 2 Study Group. Vitamin D supplement in early childhood and risk for Type I (insulin-dependent) diabetes mellitus. Diabetologia. 1999;42(1):51-4.

• Wortsman J, Matsuoka LY, Chen TC, Lu Z, Holick MF. Decreased bioavailability of vitamin D in obesity. Am J Clin Nutr. 2000;72(3):690-3.

• Zittermann A, Schleithoff SS, Koerfer R. Putting cardiovascular disease and vitamin D insufficiency into perspective. Br J Nutr. 2005;94(4):483-92.

• Zittermann A. Vitamin D and disease prevention with special reference to cardiovascular disease. Prog Biophys Mol Biol. 2006;92(1):39-48.

• Zittermann A. Vitamin D in preventive medicine: are we ignoring the evidence? Br J Nutr. 2003;89(5):552-72.