Vitamin D [25-hydroxy] in Serum

Why Is This Test Done?

Your doctor may order this test to check if you have enough vitamin D, which is important for preventing conditions like rickets in children or osteoporosis in adults. It can also help diagnose or monitor vitamin D deficiency, which may cause fatigue, muscle weakness, or bone pain. Sometimes, it’s used to assess vitamin D levels in people with certain medical conditions, like kidney disease or malabsorption disorders.

What Does the Test Involve?

A blood sample is taken from a vein in your arm. You may feel a small pinch when the needle goes in, but it usually doesn’t cause discomfort afterward. The blood sample is then sent to a lab for testing.

What to Expect Before or After the Test

There are no special preparations needed for this test. You can eat, drink, or take your usual medications as usual. If you’re pregnant or have a medical condition, let your doctor know before the test. After the blood is drawn, you can resume your normal activities immediately.

What Are Common Causes of Low or High Levels?

Low levels of vitamin D can result from insufficient sun exposure, poor diet, certain medications, or conditions that affect how your body absorbs nutrients. High levels may occur if you take too much vitamin D supplement or have certain kidney or liver diseases.