Vitamin D 25 Hydroxy
Vitamins · Blood
Available at 0 labs
No lab currently offers this test.
About this test
What is the Vitamin D 25‑Hydroxy Test?
The test measures the level of 25‑hydroxyvitamin D (25(OH)D) in the blood. 25(OH)D is the main circulating form of vitamin D and reflects overall vitamin D status from sun exposure, diet, and supplements.
Key Parameter
| Parameter | What it shows |
|---|---|
| 25(OH)D (ng/mL) | Overall vitamin D status – sufficient, insufficient, or deficient |
Why the test is done
- Routine check‑up for people at risk of deficiency (elderly, limited sun exposure, darker skin, malabsorption).
- Evaluation of symptoms such as bone pain, muscle weakness, or fatigue.
- Monitoring patients on vitamin D supplementation or with conditions affecting bone health.
- Screening in patients with chronic kidney disease, liver disease, or autoimmune disorders.
Early detection
The test can help identify signs of vitamin D deficiency or insufficiency, but it does not diagnose a disease on its own. A clinician interprets the result alongside symptoms, history, and other investigations.
What abnormal results may indicate
- Low 25(OH)D: risk of osteomalacia, rickets in children, osteoporosis, impaired immune function, or exacerbation of chronic conditions.
- High 25(OH)D: possible over‑supplementation, which can lead to hypercalcemia and kidney stones.
Factors such as recent sun exposure, diet, medications (e.g., anticonvulsants), and hydration can influence results.
Who might be advised to get this test
- Adults over 50, pregnant or lactating women, people with limited sun exposure, individuals with chronic kidney or liver disease, patients on long‑term steroids, and those with malabsorption syndromes.
Quick summary
The 25‑hydroxyvitamin D test measures your body’s vitamin D stores, helping clinicians assess bone health and guide supplementation.
Used for detecting / monitoring
Before your test
- Fasting: No fasting required.
- If combined with fasting tests: Follow the longest fasting period required by any test in the panel.
- Sample collection: A healthcare professional draws a small amount of blood (usually 5 mL) from a vein in the arm using a needle. The procedure takes about 5 minutes.
- Discomfort: Mild pinch or sting at the needle site; bruising may occur.
- Precautions: No special precautions are needed. If you are taking vitamin D supplements, inform the clinician; they may advise timing of the dose relative to the draw.
- After the test: You can resume normal activities.
Please confirm specific preparation instructions with your doctor or the laboratory. This information is for educational purposes only and does not replace professional medical advice.
Sample type: Blood
Report parameter guide
Vitamin D 25-Hydroxy
Measures the amount of vitamin D in the blood, reflecting overall vitamin D status
Low: Can indicate deficiency, which may be related to bone weakness, fatigue, or increased risk of fractures
High: Can indicate excessive intake or supplementation, which may be related to hypercalcemia or kidney stones