What is Vitamin D?

Vitamin D is a fat-soluble vitamin that is made by the body after exposure to ultraviolet rays from the sun. Vitamin D can also be obtained by taking supplements and from eating certain foods.

What does Vitamin D do in the body?

Vitamin D helps maintain normal blood levels of calcium and phosphorous. It aids in the absorption of calcium, helping to form and maintain strong bones. Vitamin D also modulates neuromuscular, immune and other cellular functions.

What does Vitamin D testing assess?

Vitamin D tests generally assess the total volume of 25-Hydroxyvitamin D (25OHD), which is the form of Vitamin D circulating in blood. Vitamin D tests may also provide information on the levels of Vitamin D2 and D3, which comprise total Vitamin D levels.

Why do physicians test for Vitamin D?

A physician generally will order a test to determine the level of Vitamin D in a patient's body. A physician would typically evaluate a test result in connection with several other factors affecting a patient's health, such as medical history, gender and age.

What information does the Vitamin D test provide?

Our Vitamin D test results provide the total level of Vitamin D found in a patient's blood serum, and the diagnostic category, such as Vitamin D deficient or sufficient, indicated by the total level. We also provide information on the levels of Vitamin D2 and Vitamin D3 in blood serum.

What are Vitamin D2 and Vitamin D3?

Vitamin D2 is derived from fungal and plant sources, and is commonly found in supplements, such as multivitamins, in the U.S. Vitamin D2 may also be used in the pharmacological treatment of Vitamin D deficiency. Vitamin D3 is derived from animal sources and is made in the skin following exposure to sunlight. The LC/MS/MS technique is able to directly quantify Vitamin D2 and Vitamin D3. By comparison, immunoassay-based Vitamin D tests can only indirectly measure Vitamin D2 and Vitamin D3.

How can I be tested for Vitamin D?

Request testing from your doctor, or visit www.MyLabReQuest.com to learn how you can order without a doctor’s order.

Do I have to fast before I submit a sample for Vitamin D testing?

No.

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