Lab tests
Vitamin B12 and folate test explainer
B12 and folate are usually ordered together, yet each comes in its own units, and a report may add less familiar lines such as active B12, red cell folate or methylmalonic acid. Add your report below to see each line named in full beside the range your laboratory printed.
Explain your vitamin B12 and folate test
- 1. Add itDrop a PDF, take a photo or paste the text.
- 2. Check itPersonal details are removed on your device. You approve what is sent.
- 3. Read itSummary, table of results, terms and questions to ask.
The explainer opens on its own page with no adverts and no outside scripts. Your file is read on your device and is never uploaded.
What you get
- Serum B12 and folate on separate rows, each in the units your report uses.
- Follow-on tests such as active B12, MMA or homocysteine named and defined where they appear.
- Any laboratory comment, for example a note that a result is indeterminate, restated in plain words.
- Questions to ask about what, if anything, happens next.
Lines you may see on a B12 and folate report
- Vitamin B12 (cobalamin)The total amount of B12 measured in the blood
- Active B12 (holotranscobalamin)The part of B12 attached to the protein that delivers it to cells
- Serum folateThe amount of folate, also called vitamin B9, in the liquid part of the blood
- Red cell folateFolate measured inside red blood cells
- Methylmalonic acid (MMA) and homocysteineSubstances some laboratories measure as a further check when a B12 or folate result is unclear
- Intrinsic factor antibodiesAntibodies against a stomach protein that is needed to absorb B12
What this tool cannot tell you
B12 and folate numbers are not read in isolation. Clinicians look at them with the blood count, symptoms, diet and medicines, and laboratories use different methods and ranges, with some reports marking a middle zone as indeterminate. MedicDecode names each line and shows what your report flags. It does not say whether you are deficient, and it does not advise on tablets or injections.
Common questions
What is the difference between B12 and active B12?
A standard B12 test measures all the B12 in the blood. Active B12 measures only the portion bound to the carrier protein that cells can take up. Laboratories offer one or the other, or use the second as a follow-up to the first.
Is folate the same as folic acid?
Folate is the general name for vitamin B9 in its various forms. Folic acid is the manufactured form used in supplements and fortified foods. A blood test reports the result as folate.
My report says indeterminate. What does that mean?
Some laboratories print a middle band between their low and normal ranges, where the test alone does not give a clear answer. Reports often suggest a further test in that case, and your clinician can tell you whether one is needed for you.
Words you may see on this report
Tap a word for its plain-English meaning, an example line and what it does not mean.
- ALT (Alanine Aminotransferase)
ALT is an enzyme found mainly in the liver; when liver cells are irritated or damaged, more ALT leaks into the blood.
- AST (Aspartate Aminotransferase)
AST is an enzyme found in the liver, muscles, heart and other tissues; raised levels can signal stress or damage in one of these.
- Bilirubin
Bilirubin is a yellow substance made when old red blood cells break down; the liver processes it so it can leave the body.
- Creatinine
Creatinine is a waste product from normal muscle activity that the kidneys filter out, so its blood level helps show how well the kidneys work.
- CRP (C-Reactive Protein)
CRP is a protein made by the liver that rises quickly when there is inflammation or infection in the body.
- Culture and Sensitivity
A culture and sensitivity test grows germs from a sample to identify them, then checks which antibiotics can stop them.
- eGFR (Estimated Glomerular Filtration Rate)
eGFR is an estimate of how well your kidneys filter waste from your blood, calculated from a creatinine blood test plus details like age.
- Electrolytes
Electrolytes are minerals in the blood, such as sodium, potassium and chloride, that carry an electric charge and help the body work.
- ESR (Erythrocyte Sedimentation Rate)
ESR measures how fast red blood cells sink in a tube of blood over an hour; a faster rate can be a general sign of inflammation.
- Fasting Sample
A fasting sample is blood taken after you have had nothing to eat or drink except water for a set number of hours.
- Ferritin
Ferritin is a protein that stores iron; its blood level gives a good idea of how much iron the body has in reserve.
- HbA1c
HbA1c shows your average blood sugar over roughly the past two to three months by measuring how much sugar is attached to red blood cells.