Vitamin D Binding Protein (Serum) Concentration

What Does This Test Measure?

Vitamin D binding protein (DBP) is a globulin produced primarily in the liver. It binds to vitamin D and its metabolites, facilitating their transport in the bloodstream. This test quantifies the concentration of DBP in your serum to evaluate its presence and potential impact on vitamin D status.

Why Might This Test Be Ordered?

Doctors may request this test if you have symptoms or conditions linked to vitamin D metabolism, such as vitamin D deficiency, kidney disease, or genetic disorders affecting protein synthesis. It can also be part of broader evaluations for conditions like hypophosphatasia or certain metabolic disorders.

Sample Collection and Preparation

A blood sample is drawn from a vein, typically in your arm, and sent to a lab. Serum is separated from blood cells and used for testing. This test does not require fasting, but follow any specific instructions your healthcare provider gives you.

How the Test Results Are Interpreted

While specific reference ranges vary by lab, results are often compared to general population norms to identify deviations. High levels may indicate overproduction of DBP, while low levels could suggest liver or kidney dysfunction or genetic factors. Your results will be discussed with your healthcare provider in the context of your overall health.