A vitamin D test is used to screen for or monitor bone disorders. It is also sometimes used to check vitamin D levels in people with chronic illnesses such as asthma, psoriasis, and certain autoimmune diseases.
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 deficiency or a healthcare practitioner suspects that you might have a vitamin D deficiency; prior to starting drug treatment for osteoporosis; periodically to monitor treatment of vitamin D deficiency
A level of 20 nanograms/milliliter to 50 ng/mL is considered adequate for healthy people. A level less than 12 ng/mL indicates vitamin D deficiency.
