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  • Test Details
  • Lab Values
  • Clinical Significance
  • Treatment Options
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Explore this test

Test Code 625

Test Details

Vitamin D, 25-OH

25-hydroxy vitamin D is a hormone precursor that promotes bone, calcium and phosphorus metabolism.

Methodology

Antibody-based chemiluminescence

Patient Preparation

None

Preferred Specimen

1.0 mL serum (0.5 mL minimum) collected in serum separator tube (SST/Tiger Top)

Transport Temperature

Refrigerated (ship on frozen cold packs)

Stability

Refrigerated: 5 days

Lab Values

Lab Values

Vitamin D, 25-OH

  • Low: <30 ng/mL
  • Mid: 30–100 ng/mL
  • High: >100 ng/mL
Test Details
Clinical Significance

Clinical Significance

Vitamin D, 25-OH

Vitamin D insufficiency is associated with:1

  • Secondary hyperparathyroidism
  • Muscle weakness with increased fall risk
  • Myalgias

Vitamin D insufficiency may be associated with:2-4

  • Deleterious effects on cardiovascular system
  • Impaired pancreatic function
  • Increased mortality
  • High doses of biotin (> 5 mg/day) may interfere with assay results. Patient assumed to be refraining from biotin supplementation for at least 3 days prior to blood draw.

References:

  1. Muscogiuri G, Sorcie GP, Ajjan R, et al. Can vitamin D deficiency cause diabetes and cardiovascular diseases? Present evidence and future perspectives. Nutr Metab Cardiovasc Dis. 2012;22(2):81-7.
  2. Goodman N, Cobin RH. Reproductive disorders. In: Camacho PM, Gharib H, Sizemore GW, eds. Evidence-Based Endocrinology. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins. 2012:190-228.
  3. Castro MR, Gharib H. Thyroid disorders. In: Camacho PM, Gharib H, Sizemore GW, eds. Evidence-Based Endocrinology. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins. 2012:43-80.
  4. Garber JR, Cobin RH, Gharib H, et al. Clinical practice guidelines for hypothyroidism in adults: cosponsored by the American Association of Clinical Endocrinologists and the American Thyroid Association. Endocr Pract. 2012;18(6):988-1028.
Lab Values
Treatment Options

Treatment Options

Vitamin D, 25-OH

  • Vitamin D, 25-OH – High levels indicated toxic levels of vitamin D. Consider discontinuing vitamin D supplements.
  • Vitamin D, 25-OH – Low vitamin D supplements. Vitamin D supplements can increase low blood levels of vitamin D, which have been associated with an increased risk of CVD and diabetes. Vitamin D supplements are frequently taken together with calcium to help maintain bone and muscle strength.
Clinical Significance