Vitamin D Binding Protein (DBP) in Serum

What Is This Test Measuring?

Vitamin D binding protein (DBP) is a globulin found in your blood that binds to vitamin D and other fat-soluble vitamins, including retinol and fat-soluble carotenoids. It helps transport these substances to tissues where they are needed. Your body produces DBP naturally, and its levels can vary based on factors like hydration, liver function, and genetic differences.

Why Might You Need This Test?

Doctors may order this test if they suspect vitamin D deficiency, liver disease, or other conditions affecting protein metabolism. It can also be part of broader evaluations for kidney function or certain genetic disorders.

Sample Collection and Preparation

A blood sample is drawn from a vein, usually in your arm. The blood is processed to separate serum (the liquid part after clotting) for testing. This test does not require fasting, but follow your healthcare provider’s instructions for optimal results.

What Does the Result Mean?

Results are not typically interpreted alone but are often used alongside other tests, such as vitamin D levels. High or low DBP levels may indicate underlying health conditions that need further investigation, such as liver disease or genetic variations.