Vitamin blood test for B12, folate, B1 and B6

A B vitamin deficiency usually builds up slowly, and the first signs are vague: tiredness, tingling in your hands or feet, trouble concentrating.

A vitamin test shows whether such a complaint could be linked to your B vitamins. The result shows where your values stand at that moment; a diagnosis comes from your GP, who knows your symptoms and your history.

Deficiencies are more common for vitamins such as vitamin B12 and folate than for B1 and B6, which mostly reflect your diet and your supplements.

This vitamin test may suit you if you:

• feel tired, have tingling or concentrate less well, without a clear cause
• eat a vegetarian or vegan diet, since vitamin B12 is found almost only in animal products
• take stomach acid reducers or metformin, which can lower B12 absorption
• are getting older, because B12 absorption from food declines with age
• have had stomach or bowel surgery, or a bowel disease such as coeliac disease or Crohn's disease
• take B vitamin supplements and want to know whether you absorb enough

This panel measures four water-soluble vitamins your body needs to function well, in one tube of blood:

• Vitamin B12: needed for your nervous system and the production of red blood cells. Read more on the vitamin B12 page.
• Folate (vitamin B9): needed for cell division and, together with B12, for red blood cells. During pregnancy the need is higher. More on the folate page.
• Vitamin B1 (thiamine): helps your body release energy from carbohydrates and supports your nerves. More on the vitamin B1 page.
• Vitamin B6: plays a role in protein metabolism and the production of haemoglobin, the red pigment in your blood. More on the vitamin B6 page.

Vitamin D, iron and ferritin are not in this panel. Vitamin D comes from sunlight and oily fish; it supports strong bones and is measured with the vitamin D test.

With vague symptoms it can make sense to look at certain vitamins and minerals together, such as B12 with iron and ferritin. Looking for such a vitamins and minerals blood test in one go? Add iron studies to the same order and you see vitamins and minerals side by side.

A low vitamin B12 or a low folate can point to low intake or poor absorption. Both deficiencies can cause anaemia, with tiredness and shortness of breath as a result. A B12 deficiency test brings such a signal into view, sometimes before your blood count changes.

A low B1 or B6 more often fits a one-sided diet or heavy alcohol use. A high B6 usually comes from supplements and can itself cause tingling.

The result describes this moment. A doctor reads the four values together with your symptoms, your diet and your medication.

For this vitamin blood test, blood is drawn at a certified draw site. After ordering you choose the site and the moment yourself. You do not need to see your GP first.

The draw takes a few minutes and is done by trained staff. The draw sites are run by independent, certified laboratories we work with.

A vitamin deficiency blood test is most useful when there is a reason for it:

• symptoms that can fit a B vitamin deficiency, such as tiredness, tingling or a sore tongue
• a diet with few or no animal products
• medication that affects absorption, such as stomach acid reducers or metformin
• an earlier low value you want to follow up
• supplement use whose effect you want to see

No symptoms and a varied diet? Then a deficiency is unlikely, severe deficiencies are rare and the result is usually reassuring.

Whether you have a deficiency, you read from your value next to the laboratory's reference range, with a short explanation per vitamin. Reference values differ between labs, so a number on its own says little.

A value below the range usually means your intake or absorption deserves attention. A value above it, for B12 and B6, often comes from supplements.

A folate test or vitamin B12 test gives you a first answer. What you do with it, you decide together with a doctor who can interpret the result in your situation and give personal advice.

You do not need to fast for this vitamin test. Drink water beforehand; it makes the draw easier.

Do you take B vitamin supplements? Then the test measures your value with the supplement. If you want to know your value without it, talk to your GP first.

Your results are online within a few working days. Vitamin B6 takes the longest, about six days; that is an estimate and differs per laboratory.

Every blood test result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.