Vitamin D, 25-OH (625)

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

Methodology

Antibody-based chemiluminescence

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.