Vitamin B12 and Vitamin B9 (Folate) Test

What are Vitamin B9 and Vitamin B12?

Vitamin B9, also known as folate, and vitamin B12, are two of the 13 essential vitamins that our body requires to function properly. These vitamins cannot be made by the body. Therefore we need to obtain them from our diet or additional supplements.

Why are vitamins B9 and B12 important?

The two vitamins play a crucial role in essential biological processes, such as DNA and red blood cells production1. These two vitamins are usually analysed together, as they are both needed for these fundamental processes to occur.

Both vitamins also have their own specific roles in the body; B12 is necessary for good nervous system health, while folate is needed for the breakdown of amino acids1,2.

Optimal levels of folate and vitamin B12 have been linked to a decreased risk of developing cancer, as poor DNA synthesis is the underlying cause of cancer.

In addition, good levels of both vitamins are required to reduce levels of homocysteine, an amino acid in the blood that has been shown to cause cardiovascular disease1.

What are the symptoms of low vitamin B9 and B12 levels?

Our bodies can store up to 3-6 months’ worth of vitamin B12 in the liver. Because of this, deficiencies tend to be quite rare and are usually caused by long-term shortages of this vitamin3.

If you have low levels of folate and B12, you are at a high risk of macrocytic anaemia, which develops due to ineffective DNA and red blood production. When this happens, red blood cells become abnormally large and their number decreases4.

The main symptoms of this disorder are:

  • Weakness
  • Shortness of breath
  • Headache
  • Palpitations
  • Pins and needles and loss of sensation

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If folate supplements are taken with this condition, the symptoms usually begin to improve. However, this can mask an underlying vitamin B12 deficiency that still needs to be treated. If this is left untreated, it can lead to permanent nerve damage and cognitive decline1.

Hence, it is necessary to track your B12 and B9 levels regularly to perform at your optimum levels. The ElevateMe health test measures them along with 20 other biomarkers that affect your core performance areas like sleep, mood, immunity, cognition, fitness, metabolism, and energy.

Who is most at risk for vitamin B9 deficiency?

As the diets of most populations have improved and become more enriched in different vitamins, vitamin B9 and B12 deficiencies have decreased significantly. However, there are still some groups who are more at risk of developing this deficiency, such as5:

  • The elderly
  • People with gastrointestinal issues that cause insufficient absorption of vitamins
  • Heavy alcohol drinkers
  • Vegetarians and vegans
  • Pregnant women who require higher levels of these vitamins
  • People with long-term use of certain medications

You are much more likely to have vitamin B12 deficiency than folate deficiency. Folate deficiency is extremely rare, with only about 2.3% of the population suffering from the condition6.

Additionally, if you have pernicious anaemia, a type of autoimmune anaemia where you cannot absorb vitamin B12, you are also at high risk of deficiency5.

What are the normal values of vitamins B9 and B12?

It’s essential to keep track of your folate and vitamin B12 levels to stay healthy.

While most labs set a lower limit for normal levels of folate to be around 4 ug/L, there is increasing evidence that this figure is simply too low to reflect long-term health.

This is one of the reasons why we use optimal ranges at ElevateMe instead of reference ranges. Optimal ranges are better than reference ranges as they consider the average values of the healthiest individuals.

In a large scientific study, the researchers found that vitamin B9 levels below 17 ug/L are associated with increased mortality rates7. Another study of 1,921 people found that the lowest risk of heart disease was seen in people with levels above 9.6 ug/L.8

Vitamin B-9 – Reference Range (ug/L)
Vitamin B-9 – Optimal Range (ug/L)

Similar scientific findings have led scientists to conclude that the vitamin B12 optimal range of 35 to 134 pmol/L leads to improved long-term health.

Vitamin B-12 – Reference Range (pmol/L)
Vitamin B-12 – Optimal Range (pmol/L)

By optimising your vitamin B9 and B12 levels, you could not only be avoiding all the negative effects of vitamin deficiency but also further improving your health to prevent disease in the future.

What are the daily vitamins B9 and B12 requirements?

The recommended dietary allowance (RDA) of vitamin B9 is 400 μg/day of dietary folate equivalents (DFEs). For pregnant women and breastfeeding women, this requirement goes up to 600 μg/day9.

Similarly, for vitamin B12, the RDA is 2.4 mcg/day. For breastfeeding and pregnant women, it is 600 mcg/day9. Most people consume more than enough folate- and vitamin B12-enriched foods to meet this requirement.

How can you increase vitamin B9 levels?

The main way you can increase your folate levels is through consuming more food that has a high content of the vitamin. This includes leafy green foods, legumes, citrus fruits, and fortified cereals10.

The foods that are rich in vitamin B12 are mostly animal products, such as meat, eggs, and dairy products. This is one of the reasons many people who keep to a vegan diet are often deficient in vitamin B12 and must take additional supplements11.

In addition, reducing alcohol intake and stopping smoking have been associated with increased levels of vitamin B1212.

Is it possible to have high levels of vitamin B9 or B12?

So far, too few studies have looked into the risks of having elevated folate levels. Nevertheless, most scientists agree that it is highly unlikely that high vitamin B9 levels are toxic, as almost 23% of the US population has elevated folate levels. Therefore, if you have elevated folate levels, there is usually nothing to worry about13.

Because vitamin B12 is not toxic in any way, it is not possible to have too much of it in the body. However, studies have found that extremely high B12 levels (above 701 pmol/L) could be a warning sign of another underlying disease, such as cancer or autoimmune diseases14. If you have elevated Vitamin B12 levels and you are not taking any supplements, you should speak to your doctor.

How is a vitamin B9 and B12 test performed?

Measuring folate and vitamin B12 in serum (liquid portion of the blood) is the most common way to analyse the levels of the vitamins in the body. To do this, a blood sample is usually used15. You do not need to fast or prepare in any way before this test.

Improving your overall health

We all know how important it is to keep our vitamin levels up by eating fortified foods. However, not everyone knows that increasing those levels to an “optimal” value can have an incredible effect on your long-term health.

When you do a health test with ElevateMe, you will receive a breakdown of 21 of your blood markers compared to optimal ranges. This, together with our tailored action plan, will help you understand the changes you need to make to truly optimise your well-being.

You can also take this free health quiz to check if your health is at its optimum level.

How’s your brain fog?

Vitamin B12 and Folate deficiency have an impact on functions related to your nervous system. This may include feeling unclear or hazy. It can also cause depression, confusion, and lethargy.  

Take an ElevateMe blood test today to capture 21 blood test insights with a single at-home blood test and track your sleep, fitness, energy, metabolism, cognition, mood, and immunity.

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  1. Sobczyńska-Malefora, A. and Harrington, D.J. (2018). Laboratory assessment of folate (vitamin B9) status. Journal of Clinical Pathology, [online] 71(11), pp.949–956.
  2. Selhub, J., Morris, M.S., Jacques, P.F. and Rosenberg, I.H. (2009). Folate– B-12 interaction in relation to cognitive impairment, anaemia, and biochemical indicators of B-12 deficiency. The American Journal of Clinical Nutrition, 89(2), pp.702S706S.
  3. Andres, E., Serraj, K., Zhu, J. and Vermorken, A.J.M. (2013). The pathophysiology of elevated vitamin B-12 in clinical practice. QJM, [online] 106(6), pp.505–515. Available at: https://academic.oup.com/qjmed/article/106/6/505/1538806
  4. Green, R. and Datta Mitra, A. (2017). Megaloblastic Anemias. Medical Clinics of North America, 101(2), pp.297–317.
  5. Koury, M.J. and Ponka, P. (2004). New insights into erythropoiesis: the roles of folate, B12, and iron. Annual review of nutrition, [online] 24, pp.105–31.
  6. Robinson, A.R. and Mladenovic, J. (2001). Lack of clinical utility of folate levels in the evaluation of macrocytosis or anaemia. The American Journal of Medicine, [online] 110(2), pp.88–90.
  7. Peng, Y., Dong, B. and Wang, Z. (2016). Serum folate concentrations and all-cause, cardiovascular disease and cancer mortality: A cohort study based on 1999-2010 National Health and Nutrition Examination Survey (NHANES). International Journal of Cardiology, [online] 219, pp.136–142. Available at: https://www.ncbi.nlm.nih.gov/pubmed/27323339
  8. Braun, R.D. (1996). Serum Folate and Risk of Fatal Coronary Heart Disease. JAMA: The Journal of the American Medical Association, 276(15), p.1222.
  9. Institute of Medicine, Food and Nutrition Board. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B(6), Folate, Vitamin B(12), Pantothenic Acid, Biotin, and Choline. Washington, DC: National Academies Press; 1998.
  10. Fenech, M. (2012). Folate (vitamin B9) and B12 and their function in the maintenance of nuclear and mitochondrial genome integrity. Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis, 733(1-2), pp.21–33.
  11. Antony, A.C. (2003). Vegetarianism and vitamin B-12 (cobalamin) deficiency. The American Journal of Clinical Nutrition, [online] 78(1), pp.3–6. Available at: https://academic.oup.com/ajcn/article/78/1/3/4689891
  12. Tungtrongchitr, R., Pongpaew, P., Soonthornruengyot, M., Viroonudomphol, D., Vudhivai, N., Tungtrongchitr, A., Phonrat, B., Pooudong, S. and Schelp, F.P. (2003). Relationship of tobacco smoking with serum vitamin B12, folic acid and haematological indices in healthy adults. Public Health Nutrition, 6(7), pp.675–681.
  13. Mills, J.L., Carter, T.C., Scott, J.M., Troendle, J.F., Gibney, E.R., Shane, B., Kirke, P.N., Ueland, P.M., Brody, L.C. and Molloy, A.M. (2011). Do high blood folate concentrations exacerbate metabolic abnormalities in people with low B-12 status? The American Journal of Clinical Nutrition, 94(2), pp.495–500.
  14. Andres, E., Serraj, K., Zhu, J. and Vermorken, A.J.M. (2013). The pathophysiology of elevated vitamin B12 in clinical practice. QJM, [online] 106(6), pp.505–515. Available at: https://academic.oup.com/qjmed/article/106/6/505/1538806
  15. labtestsonline.org.uk. (2016). Vitamin B12 & Folate. [online] Available at: https://labtestsonline.org.uk/tests/vitamin-b12-and-folate.

Written by Natalia Glazman

I'm a Biochemistry student at Imperial College, interested in all things immunology and pursuing a career in science communication.


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