Vitamin Level Testing

Vitamin level testing measures the amount of one or more vitamins in a blood sample. It is ordered when a deficiency or excess is suspected, or to monitor a known vitamin problem or its treatment.

What it measures

Vitamin B12 — Helps make red blood cells and keep nerves healthy.
Folate (vitamin B9) — Works with B12 for cell growth and red blood cell production.
Vitamin D — Supports bone strength and calcium balance.
Vitamin A — Supports vision, skin, and immune function.
Vitamin E — An antioxidant that protects cells from damage.
Vitamin K — Helps blood clot and supports bone health.

Who it is for

A clinician may order vitamin testing for people with symptoms such as fatigue, tingling, or unusual bleeding, or for those with diets, surgeries, or conditions that affect vitamin absorption.

Preparation

Preparation depends on which vitamins are checked. Some tests need fasting or a specific time of day; others need no preparation. Follow the instructions given with your order.

Results and what they mean

Results are reported as a number for each vitamin measured, often with a reference range. A clinician interprets these values alongside your symptoms, diet, and other tests. This is general information, not medical advice; discuss your results with a qualified clinician.

How to order this test

Choose the test and place a confidential order online.
Select a certified collection site and pick a time that suits you.
Have your specimen collected — most draws take only a few minutes.
Review results in a secure portal, typically within 1–3 days.

Preparation, hours, and pricing vary by site; confirm details directly with the lab before your visit.

Availability by state

Direct-access online ordering for the vitamin level testing is available in most states. It is currently unavailable in 6 states:

Everywhere else you can order confidentially and collect your sample at a certified site. Browse by state →

Frequently asked questions

Do I need to fast for vitamin testing?

Only if your clinician or lab instructs you to. Many vitamin tests do not require fasting, but some do.

How long until I get results?

Results are typically available within 1 to 3 business days, though timing can vary by lab.

Can I take my vitamins before the test?

Ask your clinician. Some supplements can affect results, so you may be told to pause them beforehand.

What if my level is outside the reference range?

A value outside the range does not always mean a problem. Your clinician will consider the full picture and decide whether more testing or changes are needed.