25-Hydroxy Vitamin D, Serum

25-Hydroxy Vitamin D, Serum

What it is

The 25-Hydroxy Vitamin D test measures the main circulating form of vitamin D in the blood. It is considered the most accurate way to assess vitamin D status in the body, reflecting both dietary intake and sunlight exposure.

Uses

This test is commonly used to diagnose vitamin D deficiency or excess, evaluate causes of bone disorders such as rickets, osteomalacia, and osteoporosis, and monitor patients receiving vitamin D supplementation.

Symptoms That May Lead to the Test

Doctors may recommend the test if you experience bone pain or tenderness, frequent fractures, muscle weakness, chronic fatigue, or abnormal growth patterns in children.

Abnormal Results

Low Vitamin D: Indicates deficiency, which may result from poor nutrition, malabsorption, chronic kidney or liver disease, or inadequate sunlight exposure.

High Vitamin D: Often due to excessive supplementation, and may also be seen in conditions like sarcoidosis or certain lymphomas.

Risks

The test is a standard blood draw with minimal risks, which may include mild pain, bruising, or bleeding at the puncture site, and rarely dizziness or infection.