LabInformationLab tests, explained

Vitamin B12 Deficiency Test in California

Vitamin B12 Deficiency Test is a laboratory test you can order directly. A vitamin B12 deficiency test measures the level of vitamin B12 in your blood. It is ordered when you have symptoms like fatigue, tingling in hands or feet, or when a clinician suspects poor absorption or a diet low in B12. Across California, part of Pacific, the vitamin b12 deficiency test can be ordered directly and collected at a certified site — no referral required.

Sample type
blood
Category
Vitamin & Mineral
Turnaround
1-3 business days
Price
$35
Referral
Not required

A vitamin B12 deficiency test measures the level of vitamin B12 in your blood. It is ordered when you have symptoms like fatigue, tingling in hands or feet, or when a clinician suspects poor absorption or a diet low in B12.

What it measures

  • Vitamin B12 (cobalamin) — The main measurement of B12 in your blood.
  • Folate (folic acid) — Often checked because low folate can cause similar symptoms.
  • Methylmalonic acid (MMA) — A substance that rises when B12 is low; helps confirm deficiency.
  • Homocysteine — Another marker that can be elevated with low B12.
  • Complete blood count (CBC) — Checks for anemia, which can be caused by low B12.

Who it is for

A clinician may order this test if you have symptoms of deficiency, a diet low in animal products, or conditions that affect absorption like celiac disease or gastric surgery.

Preparation

Usually no fasting is required. Tell your clinician about any supplements you take, as they can affect results.

Results and what they mean

Results are reported as numbers with a reference range. Your clinician interprets them along with your symptoms and history. This is general information, not medical advice.

Requesting the Vitamin B12 Deficiency Test in California

Order online, choose a certified collection site in California, and review results through a secure portal. No referral is required, and orders are processed confidentially. Because the region is uneven, coastal metros, inland towns, and rural counties with very different access to testing — worth planning around when you book.

Frequently asked questions

Do I need to fast for this test?

No, fasting is not typically needed.

What can cause low B12?

Common causes include a vegan diet, problems absorbing B12 from food, and certain medications.

How long until I get results?

Most results are ready within 1 to 3 business days.

Can I take B12 supplements before the test?

Supplements can raise your B12 level, so ask your clinician if you should stop them before testing.

Vitamin B12 Deficiency Test by city in California

All testing in California →   Full Vitamin B12 Deficiency Test guide →