25-Hydroxy Vitamin D3 (25(OH)D) Blood Level

Why Is This Test Done?

Your healthcare provider may order this test if you have symptoms of vitamin D deficiency, such as muscle weakness, bone pain, or frequent illnesses. It may also be used to monitor vitamin D levels in people who take supplements or have conditions that affect vitamin D absorption, like malabsorption disorders or limited sun exposure.

How Is the Test Performed?

A blood sample is taken from a vein in your arm. You may feel a slight pinch, but it usually doesn’t cause discomfort. The sample is then sent to a lab for analysis using an immunoassay method to measure the precise amount of 25-hydroxy vitamin D.

What Do the Results Mean?

Results help determine if your vitamin D levels are sufficient, insufficient, or very low. While specific ranges can vary by lab, lower levels may indicate a need for dietary changes, sun exposure adjustments, or supplements to support overall health.

Common Causes of Low Vitamin D Levels

Vitamin D deficiency can result from limited sun exposure, poor diet, certain medical conditions (like celiac disease or kidney issues), or medications that interfere with its absorption. Some ethnic groups may also have higher risks due to differences in skin pigmentation.