Vitamin B9: The Pregnancy Vitamin

What comes to mind when you hear ‘vitamin B9’? Probably nothing in particular.
More commonly known as ‘folic acid’, vitamin B9 is a key supplement during pregnancy. So, unless you’re pregnant or close to someone who is, you probably don’t know much about it. It’s worth changing that, because vitamin B9 is equally important for all of us.

Let’s take a closer look at its functions.

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Names: Vitamin B9, folate, folic acid

Best known for: Ensuring normal cell division and growth; production of red blood cells; DNA and RNA synthesis.

Good sources: Liver, spinach, asparagus. Also found in a variety of fruits, nuts, beans and seafood.

Recommended dietary allowance (RDA): 330 mcg/day for healthy adults; 600 mcg/day during pregnancy. The maximum intake level of folic acid unlikely to cause side effects is 1 mg/day.

Good to know: Vitamin B9 corrects some of the symptoms of a vitamin B12 deficiency, making it more difficult to diagnose and treat.

Vitamin B9 (folic acid) in Jake:
Jake Light and Original: 33% of RDA
Jake Sports: 25% of RDA
Vitaminbars: 25% of RDA

What is vitamin B9?

Vitamin B9 is a water-soluble vitaminVitamins can be water-soluble and fat-soluble. Water-soluble vitamins can be dissolved in water and are not stored in the body. It’s most commonly known as folate or folic acid. These two forms of vitamin B9 are slightly different.

Folate refers to the naturally-occurring vitamin B9 found in food. In the digestive system, it’s first converted to its active form, 5-methyltetrahydrofolate, before it enters the bloodstream.

Folic acid is the synthetic form of vitamin B9 and is often preferred as a dietary supplement, due to its high bioavailabilityThe degree to which a substance is absorbed in the body and can be utilised for physiological functions.. Your body will absorb around 18% more folic acid than folate from an equal intake of each.

Health benefits of vitamin B9

Vitamin B9 acts as a coenzymeEnzymes are substances, mostly proteins, that speed up biochemical reactions in the body. A coenzyme is a substance that helps enzymes do their job.. It partners with proteins and ensures their biological activation – the process which allows them to perform their function in the body. One of the most important reactions that depend on vitamin B9 is related to the synthesis of S-adenosyl methionine, SAM. SAM regulates key processes in your cells, including protein metabolism, immune response and DNA synthesis.

The key functions that depend on vitamin B9 are:

  • Regulation of gene expression: Vitamin B9 helps the synthesis and maintenance of DNADeoxyribonucleic acid (DNA) is the carrier of genetic information in humans. and RNARibonucleic acid (RNA) conveys genetic information from DNA to initiate the synthesis of specific proteins that regulate gene expression., which are responsible for turning genes ‘on’ and ‘off’.
  • Cell division and growth: Vitamin B9 is essential for cell replication. This makes it especially important during times of rapid tissue growth, such as pregnancy and infancy.
  • Production of red blood cells.

Some studies suggest a potential dual role of vitamin B9 in cancer developmentSource: Molecular Nutrition and Food Research. Modest doses seem to suppress the development of cancer in normal tissues. At the same time, high doses administered after the first appearance of abnormal cells seem to enhance cancer progression. Further research is needed to fully understand the connection between vitamin B9 and cancer.

How much vitamin B9 do you need?

Healthy adults need 330 mcg of vitamin B9 per day to meet their dietary needs.This amount reflects the recommended dietary allowance (RDA) according to the European Food Safety Authority (EFSA). An RDA is the average daily intake sufficient to meet the nutritional requirements of 97-98% of healthy individuals. In practical terms, this equals 130 grams of beef liver.

Women of childbearing age are advised to take 400 mcg of vitamin B9 per day as early as possible prior to conception. During pregnancy and lactation, the recommended daily intake is increased to 600 mcg and 500 mcg, respectively.

Vitamin B9 in foods

True to its name, vitamin B9 is found in many dark green leafy vegetables. However, there are various other sources of vitamin B9, including liver, yeast, some fruits, nuts, beans and seafood.

These are the top sources of vitamin B9:

FoodRDA (%)*Vitamin B9 (mcg)
Beef liver (100 g)77%253
Spinach, raw (100 g)59%194
Asparagus, boiled (100 g)45%149
Peas, green, raw (100 g)20%65
Brussels sprouts, boiled (100 g)18%60

* Based on the recommended dietary allowance (RDA) established by EFSA for healthy adults (330 mcg/day)

What if you’re not getting enough vitamin B9?

Vitamin B9 deficiency is quite rare on its own. It’s usually associated with deficiencies in other nutrients.

The main sign of vitamin B9 deficiency is megaloblastic anaemiaAnaemia is a pretty serious blood disorder characterised by a decrease in the number of red blood cells. Megaloblastic anaemia is a type of anaemia that is further associated with unusually large red blood cells. Due to their size, red blood cells may not be able to exit the bone marrow and enter the bloodstream to deliver oxygen., characterised by weakness, fatigue, poor concentration, irritability and shortness of breath. Insufficient intake of vitamin B9 can also alter the pigmentation of skin, hair or nails.

The following groups are at a risk of vitamin B9 deficiency:

  • Pregnant women: Insufficient vitamin B9 intake can increase the risk of malformations of the baby’s spine, skull and brain. These malformations are commonly known as neural tube defects (NTD). The exact mechanism that causes NTDs is not fully understood. However, consuming enough vitamin B9 can help prevent them.
  • People with chronic alcoholism: Alcohol inhibits the absorption of vitamin B9.

If you spend a lot of time in the sun, keep in mind that UV light destroys vitamin B9 in your body. This could have health consequences, especially for pregnant women Source: Journal of Photochemistry and Photobiology B: Biologywhose vitamin B9 needs are higher compared to the general population.

How much vitamin B9 is too much?

There is currently no evidence of negative health effects following high intakes of the naturally occurring form of vitamin B9, folate. However, excessive consumption of folic acid is associated with a certain health benefit that is actually a health risk, too: Folic acid doses higher than 5mg/day can ‘mask’ a vitamin B12 deficiency by correcting anaemia, one of its typical symptoms. As a result, diagnosis and treatment of a vitamin B12 deficiency can be delayed, potentially leading to permanent brain, spine and nerve damage.

To avoid negative health consequences, folic acid consumption should be limited to a maximum of 1mg/day.This is the tolerable upper intake level (UL) set by the European Food Safety Authority (EFSA). No adverse health effects are expected at this level of intake.


These are the top things to remember about vitamin B9:

  • It’s important for cell division, tissue growth and gene expression. That makes it essential during periods of rapid growth, like pregnancy and infancy.
  • You can find it in a variety of foods. The top sources of vitamin B9 are liver, spinach, peas and asparagus.
  • If you consume excessive amounts of vitamin B9 (>5mg/day) over time, it can obstruct the diagnosis and treatment of a vitamin B12 deficiency, with potential long-term health consequences.
  • Women of childbearing age are advised to start supplementation with vitamin B9 at least three months before conception to prevent birth defects.