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Vitamin D Tests

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Also known as: Ergocalciferol (Vitamin D2); Cholecalciferol (Vitamin D3); Calcidiol (25-hydroxyvitamin D[25(OH)D]); Calcifidiol (25-hydroxy-vitamin D); Calcitriol (1,25 dihydroxy-vitamin D [1,25(OH)(2)D])
Formal name: 25-hydroxyvitamin D; 1,25 dihydroxyvitamin D

At a Glance

Why Get Tested?

To determine if you have a vitamin D deficiency; if you are receiving vitamin D supplementation, to determine if it is adequate

When to Get Tested?

When you have an abnormal calcium, phosphorus, and/or parathyroid hormone level; when you have evidence of bone disease or bone weakness; when you are at high risk of deciency or your doctor suspects that you might have a vitamin D deficiency; prior to starting drug treatment for osteoporosis; periodically to monitor treatment of vitamin D deficiency

Sample Required?

A blood sample drawn from a vein in your arm

Test Preparation Needed?