Vitamin D, 25-Hydroxy, Total, Immunoassay

Catalog information reviewed: August 24, 2026 by the Sunridge Medical clinical team.

What this laboratory test evaluates

DetailsVitamin D, 25-Hydroxy, Total, Immunoassay – This test measures the level of Vitamin D in your body, which is crucial for bone health. It's especially useful for people without kidney disease to check if they have the right amount of Vitamin D. Low levels might mean you're not getting enough Vitamin D from your diet, your body isn't absorbing it well, or your liver isn't processing it correctly. This can lead to bone issues like rickets in children or osteomalacia in adults. High levels of Vitamin D can cause a condition called hypercalcemia.

Who might need this test?Doctors might order this test if you show signs of Vitamin D deficiency or have bone health concerns.

Vitamin D Deficiency Symptoms:• Bone pain and weakness
• Muscle weakness
• Mood changes, like feeling sad
• Getting sick often

What type of sample is required for this test?0.8 mL serum. A simple blood draw is needed.

Test Resources • https://education.questdiagnostics.com/faq/FAQ199
• https://www.questdiagnostics.com/content/dam/corporate/restricted/documents/test-directory/vit-d-db066889v-in-range.pdf
• https://www.questdiagnostics.com/content/dam/corporate/restricted/documents/test-directory/vit-d-db066890v-out-of-range.pdf

Additional test information

This test measures the level of Vitamin D in your body, which is crucial for bone health. It's especially useful for people without kidney disease to check if they have the right amount of Vitamin D.

Collection and processing

• Sample type: Serum
• Fasting: No
• Estimated laboratory processing: Results should be available in 2 – 5 business days after the sample is collected

How Sunridge uses laboratory information

Sunridge considers the medical question, symptoms, history, medications, prior results, and whether the finding could change care before recommending testing. A laboratory result is not interpreted in isolation and does not establish a diagnosis by itself.

Before requesting this test

Availability, collection requirements, eligibility, and processing estimates can change. Sunridge reviews each request and, when appropriate, creates the order through Fullscript. Follow the current instructions supplied with the approved order.