What's the relationship between vitamin B12 and folate?

Why getting the right amounts of B12 and folate is crucial during your pregnancy journey.
Written by
Lucinda Starr
Reviewed by
Last updated on
February 28, 2024
min read
Vitamin B12 & Folate – What's The Relationship | Kin Fertility
Jump to:
Arrow Down

Maintaining a balanced, vitamin-rich diet is important at all stages of life, but especially when you’re pregnant — your body is literally growing a human! B12 and folate are two vitamins that are essential for a healthy pregnancy as they are key to supporting growth and preventing foetal abnormalities.

Deficiencies or imbalances of these vitamins can cause your body to develop a blood disorder known as folate deficiency anaemia or B12 deficiency anaemia, which can have negative health flow-on effects on you and your baby.

Here's a detailed look at why getting the right amounts of B12 and folate is crucial during your pregnancy journey.

What is folate?

Folate is the natural form of vitamin B9 that supports healthy cell division and foetal growth [1]. It's naturally present in foods like beans, leafy green vegetables, asparagus and broccoli. However, folate dissolves in water, meaning it can effectively be "cooked out" of foods.

If you are unable to get enough folate in your diet, you can top up with folic acid — a synthetic form of folate.

Folic acid is found in many fortified foods including cereal, bread, and pasta.

It's good to be aware that the body finds it easier to absorb folate or folic acid (85% versus 50%) [2]. The liver can only process a certain amount of folic acid at a time, so it gets broken into smaller compounds.

This can mean that it is possible to consume too much folic acid — something to be extremely mindful of.

What is B12?

B12, also known as Cobalamin, is also a water-soluble vitamin naturally found in some animal foods such as fish, meat, especially poultry, and dairy — it can also be added to food and supplements

This vitamin plays a crucial role in forming red blood cells and DNA, as well as brain development and nerve maintenance. As B12 is bound to the protein in foods, it must be released before it can be absorbed by the body.

This process starts in the mouth when food is mixed with saliva and continues in the stomach with hydrochloric acid and enzymes unbinding vitamin B12 into its free form [4].

B12 is especially beneficial for pregnant people as it not only supports healthy foetal development but assists in maintaining the nervous system. Pregnant people are advised to take around 2.6 mcg of Cobalamin per day, which is slightly more than the recommended 2.4 mcg dose for adults [4].

What are the benefits of folate and B12?

The benefits of folate and vitamin B12 are endless. Folate helps tissues grow and cells work properly. B12 helps the body to break that folate down and use it to create new proteins and form healthy red blood cells.

Red blood cells carry oxygen around the body using a substance called haemoglobin. This helps prevent anaemia — the condition where you have fewer blood cells than normal, or an abnormally low amount of haemoglobin in each red blood cell [5].

These vitamins are especially important in conception and early pregnancy to promote healthy embryo development. Research has shown that good levels of folate and B12 can decrease the risk of neural tube defects, particularly spina bifida [6].

Why are folate and vitamin B12 important for pregnancy?

As we've mentioned, folate and vitamin B12 work together to support healthy cell growth and baby development. It's typical to have insufficient levels of B12 during pregnancy but thankfully, you can improve your intake with the right foods and supplements.

While B12 isn’t something your body naturally produces, it is found in many animal products, making it easy to incorporate into your diet.

In fact, approximately 1 in 3 people struggle to convert folic acid due to a common gene variant (the MTHFR gene), so using methylated folate means you're getting the good stuff and your body is actually able to use it effectively.

When it comes to B12 deficiency, it can increase the chance of lowering your baby's birth weight and might contribute to other negative health consequences. Maintaining good levels of folate during pregnancy is important for preventing neural tube defects and spina bifida [8].

Spina bifida is one of the most common birth defects and occurs during the first weeks of pregnancy (typically week 5 or 6), so ensuring your vitamin levels are intact before you start trying to conceive is vital.

What causes a vitamin B12 or folate deficiency?

There are several reasons for a vitamin B12 or folate deficiency [5].

These include:

  • Pernicious anaemia is an autoimmune condition whereby vitamin b12 absorption is affected by your immune system attacking healthy cells in your stomach.
  • Digestive system diseases like Crohn's disease and coeliac disease can stop the proper absorption of folate and folic acid.
  • Medicines affecting absorption such as anticonvulsants, proton pump inhibitors (PPIs), a medicine sometimes used to treat indigestion, some anti-seizure drugs — as well as kidney dialysis.
  • Lack of vitamins in your diet. This is less common and mainly affects vegans who don't consume animal foods and who aren't taking any B12 supplements. An issue with folate consumption can also be caused by overcooking fruit and vegetables and the heat destroying the naturally occurring folate. Interestingly, stores of vitamin B12 can last up to 2-4 years in the body without being replenished, so you may not notice any issues from a diet change for some time [9].
  • Surgery that removes or bypasses the end of the small intestine where vitamin B12 is absorbed.
  • Lack of intrinsic factor, which is a protein made in the stomach that is needed to absorb vitamin B12. This type of B12 deficiency anaemia is called pernicious anaemia.

Symptoms of vitamin B12 or folate deficiency

If you're not getting regular blood tests, how do you know if you have a vitamin B12 or folate deficiency? 

One of the first signs of a folate deficiency is fatigue, however, because fatigue is a fairly common symptom, it can be difficult to pinpoint a lack of folate as the primary cause.

Other, folate deficiency symptoms to look out for include:

  • Paleness
  • Shortness of breath
  • Irritability
  • Dizziness
  • Tender, red tongue
  • Mouth sores or ulcers
  • Reduced sense of taste
  • Diarrhoea
  • Numbness
  • Memory loss [10].

Symptoms of B12 anaemia or a deficiency include:

  • Numb or tingling feeling in hands and feet
  • Trouble walking
  • Nausea
  • Decreased appetite
  • Weight loss
  • Irritability
  • Lack of energy or tiring easily (fatigue)
  • Diarrhoea
  • Smooth and tender tongue
  • Fast heart rate [11].

How is vitamin B12 deficiency anaemia treated?

Your medical practitioner will work with you to diagnose a vitamin B12 deficiency through a routine blood test. Once identified, there are some simple ways to boost your levels. Folate and B12 deficiencies are typically treated together as they are hard to tell apart.

Treatment options include:

  • A vitamin B12 shot. There are two types of vitamin B12 injections: hydroxocobalamin and cyanocobalamin. Hydroxocobalamin is usually the recommended option as it stays in the body for longer.
  • Folic acid supplements or tablets.
  • Diet changes including a healthy, balanced diet with foods rich in B12 and folate or folic acid [11].

Your treatment path will depend on whether you're pregnant, how severe your deficiency is and your age. If you increase your folate or B12 intake, the effects of your deficiency should reverse fairly quickly.

Can you take B12 and folate together?

It's usually recommended to start taking a B12 supplement before a folic acid supplement or increasing your intake of folate. That's because folic acid can mask the symptoms of a B12 deficiency [12].

Before you start taking folic acid, your GP will check your vitamin B12 levels to make sure they're normal. This is because folic acid treatment can sometimes improve your symptoms so much that it masks an underlying vitamin B12 deficiency.

If you suspect you have a deficiency or are unsure, remember to consult your doctor to ensure you are making a safe decision for your body and potentially, your unborn child.

Before you start taking folic acid, your GP will check your vitamin B12 levels to make sure they're normal.

How do folate and B12 work together?

Vitamin B12 has a close relationship with folate, as both depend on the other to work properly [13]. The B-group vitamins, including B12, work together to help with your body's metabolic processes.

This includes helping break folate down to create new proteins and forming healthy red blood cells.

Sources of folate and B12 for pregnancy

While folate and B12 can both be sourced from foods, to ensure you are getting enough of these vitamins while pregnant, you can also take a supplement. For people who are planning a pregnancy, or are in the first 3 months of pregnancy, a daily folic acid supplement of 500 micrograms is recommended [13].

To achieve the recommended amount of B12/Cobalamin per day, you may also want to take a high-quality supplement [4]. 

Kin’s Prenatal Vitamin is an excellent option — it contains 652mg of methylated folate to help support your baby’s brain development, as well as 250mcg of vitamin B12 to maintain healthy foetal growth.

Remember, if you suspect you have a folate or B12 deficiency and are pregnant or looking to conceive, chat with your medical professional.

They'll be able to point you in the right direction of what treatments and supplements are right for your body.

All of the tools you need to take your reproductive health into your own hands.