Last updated: August 27, 2021

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Today the use of folic acid is often associate with pregnancy and lactation. You may even know that folic acid is routinely prescribed as part of prenatal care; but do you know why? In this article, we’ll answer all of your questions about this amazing nutrient: when it was discovered, its functions and why it is a popular supplement among pregnant women.

You’ll learn that folic acid contributes to the proper development of cells and DNA replication. With this in mind, it should be of no surprise that it also has a great importance in foetal proper development. Nonetheless, we should also note that this supplement can be a beneficial addition to anyone's diet, pregnant or not. Want to know more? Keep reading!

Key Facts

  • Folic ​acid is the synthetic form of vitamin B9 (folate).
  • Natural folate is abundant in many foods of plant origin, especially leafy green vegetables and legumes.
  • Vitamin B9 is crucial for proper cell​ division and DNA replication. A deficiency of this vitamin will cause foetus malformations and anaemia. An untreated deficiency has the potential of having serious neurological consequences for both the mother and baby.

The best folic acid supplements

This ranking is designed to help you choose from the best folic acid supplements available to you on the market. After diligent research, we have chosen five quality products that stand out above all the rest. If you want a top-quality folic acid supplement at an affordable price, look no further. We are certain that in this list you will find what you’re looking for.

Shopping Guide: Everything you should know about folic acid

Folic acid (vitamin B9) is an essential nutrient for pregnant women and their future children, since it works to prevent the onset of foetal malformations. Nevertheless, keep in mind that the rest of the population requires folic acid (or folate) to support the overall health of their bodies as well. This nutrient provides energy, prevents anaemia and it actively works to decrease the risk of developing a heart disease.

Mom with her baby

Folic acid is essential for the well being of the cells in our body. (Fuente: subbotina: 25227239/

What is folic acid exactly?

In 1931, the famous haematologist Lucy Wills discovered that it was possible to treat anaemia in pregnant women by drinking brewer's yeast, rich in folate. Years later, the first artificial folate supplements (from spinach extract) were synthesised in the form of folic acid.

Folate is an essential nutrient required for a healthy life, it regulates and supports DNA replication and the proper formation of new cells. This organic compound is also known as vitamin B9 - The terms folate and folic acid refer to the Latin word folium (leaf), which is where this nutrient originates from.

Healthy food, sources of folic acid (vitamin B9)

Ingesting foods rich in folic acid poses many benefits to our health. (Fuente: : ????????? ?????????: 77402770/

Remember that B vitamins are water-soluble. This means that they are not only dissolved within the water in our food, but it also dictates how these vitamin are taken up by our bodies. This also means that an overdose of these vitamins can be easily treated by drinking plenty of water, which will allow for renal (urine) elimination. It is for this reason that cases of toxicity from the excess of vitamin B9 are infrequent and very rare.

What is the difference between folate and folic acid?

Vitamin B9 exists in its natural form (folate) or as an artificial product (folic acid). Even though they are essentially the same compound, there are small differences between the structures of these molecules. Due to these small differences, folic acid is metabolised, absorbed and used by the body in a substantially different way than the folate, it’s naturally occurring form.

Part of the folate in food is automatically transformed into the active form of vitamin B9 (folic acid) during digestion. However, the activation by our bodies of folic acid is slower and requires the liver to be involved. It is for this reason that synthetic vitamin B9 can accumulate in the bloodstream, as it waits to be metabolised.

Healthy food, sources of folic acid (vitamin B9)

Broccoli, avocado, papaya, cashes, salmon... The list goes on and on. There are no excuses to have a lack of folic acid in your diet. (Fuente: ????????? ?????????: 77993448/

Some people actually prefer to get vitamin B9 from natural sources, especially since recent research has linked high levels of synthetic folic acid to the emergence of certain diseases. In the table below, we have illustrated the main differences between folate and folic acid:

Folate Folic acid
Origin Natural (present in foods). Artificial (supplements and fortified foods).
Activation Intestinal and hepatic. Done in liver.
Bioaccumulation (what happens with the excess?) There is no excessive or toxic build-up. Excess builds up in the blood, which may be toxic.
Toxicity No toxicity associated with high levels in the system. May mask symptoms of B12 deficiency. High concentrations that are not 
metabolised may be toxic.
(capacity of absorption by the body)
Varies (approximately 50%). Very high: 100% (supplements) and 85% (fortified foods).
Suggestions Recommended for daily intake. Recommended supplementation during pregnancy and lactation.

What is the function of folate in the body?

Vitamin B9, or folate, acts in conjunction with vitamin B12. Together, they support to the process of DNA replication and cell synthesis, promoting the creation of new blood cells and the renewal of body tissues. In children, this process is crucial for growth and development.

Moreover, folate has been shown to help lower blood homocysteine levels. Homocysteine is an amino acid that in high amounts has been linked to cardiovascular diseases. Furthermore, folate can transform excess homocysteine into methionine, another less dangerous amino acid.

What is the recommended daily dose of folate?

It is important to consume an adequate amount of folate daily in order to keep the levels of this vitamin within healthy levels. In the table below, you can find the recommended daily dose of vitamin B9 depending on age, sex and other factors such as pregnancy:

Population group Dose (micrograms per day)
Infants 0-6 months 65
Infants 7-12 months 80
Toddlers 1-3 years 150
Boys and girls 4-8 years 200
Boys and girls 9-13 years 300
Men older than 14 years 400
Women older than 14 years 400
Pregnant or planning pregnancy 600-800
Breastfeeding women 500

To ensure the proper development of the foetus, experts recommend increasing the dosage of folate in pregnant women. This recommended daily dose of B9 can be achieved by incorporating a diet rich in folate, even though supplementation or the consumption of foods fortified with folic acid is generally preferred.

How does a folate deficiency occur?

Vitamin B9 deficiency may occur if folate intake is inadequate (prolonged fasting or a low nutrient diet), if there are problems of malabsorption (Crohn's disease, celiac disease), if the folate intake needs to be higher than normal (pregnancy and lactation), or if there is a loss of folate (use of certain medications).

There is another hypothesis that links a decrease in folate levels with the excessive use of tanning beds. Ultraviolet light has been shown to degrade and deactivate vitamin B9, so it has been deduced that the indiscriminate use of UV equipment on the skin could potentially reduce blood folate levels.

A 2014 study from the University of Queensland (Australia) found that young women who were exposed to UV radiation from the sun after taking folic acid showed a decrease in the overall effectiveness of their supplement.

How does folate deficiency manifest in the body?

Chronic folate deficiency is rarely found, this makes sense if we consider that much of the processed foods available to to us (such as cereals, biscuits or pastries) have been fortified with folic acid. Even so, this deficiency can appear in certain population groups and give rise to undesirable symptoms, such as:

  • Neural tube defects in the foetus: Folic acid deficiency has been associated with an increase in foetal malformations such as spina bifida (alterations in the formation of the spinal cord) and anencephaly (absence of brain or skull).
  • Cutaneous and capillary alterations: Folate deficiencies can manifest by desquamation and dryness of the skin. It is also possible that alterations in hair colour may appear, generally in the form of premature greying.
  • Anaemia: Anaemia is defined as a deficiency in the number or quality of red blood cells in your body. This deficiency negatively affects the transport of oxygen and nutrients to body tissues. This type if anaemia is megaloblastic (red blood cells increased in size) and it can be confused with the anaemia caused by vitamin B12 deficiency.
  • Negative neurological and psychiatric repercussions: If anaemic levels persist for an extended period of time, symptoms such as memory problems, insomnia (at night), drowsiness (during the day), alterations in sensitivities, balance, depression and even dementia will begin to appear.

The onset of anaemia and neuropsychiatric disorders is slow and may go unnoticed in adults. A healthy person has a reserve of folate in their organism. If the patient suffers from a folate deficit (due to malnutrition or illness for example), the effects of folate deprivation will take about four months to appear.

Another form of B9 deficiency is an acute deficit. In this case, there is a loss of folate due to the use of certain drugs, such as methotrexate (anti-tumour agent), the appearance of dermatitis, diarrhoea, and ulcers in the mouth and tongue. This type of medication is usually accompanied by a supplement that mitigates the occurrence of most of these complications and side effects.

sport, fitness, healthy lifestyle and people concept - close up of man with jar and bottle preparing protein shake

If you wish to manage your folic acid dosage down to the gram, your best option is to opt for a powder supplement. (Fuente: dolgachov: 54776175/

What foods are rich in folate?

Vegetables, such as leafy greens and legumes, are rich in folate. This vitamin can also be found in foods of animal origin, such as veal liver or fatty fish.

Below is a table that includes information on the main sources of folate:

Food Folate dose (mcg) per serving Recommended daily dose %
Lentils 358 90
Chickpeas 282 71
Spinach 263 65
Asparagus 262 65
Veal liver 212 52
Chard 177 44
Papaya 115 29
Avocado 110 28
Peanut 88 22
Broccoli 84 21
Orange 40 10
Salmon 14 4

However, remember that cooking eliminates some of the folate present in these foods, considerably reducing their nutritional content. If you want to make the most of your diet and increase your intake of vitamin B9, increase your intake of raw fruit and vegetables. Steaming and the use of microwaves also reduces the loss of folate during cooking.

Unfortunately, these tips to eat raw foods are not always extended to pregnant women. Usually, pregnant women are advised to eat well-cooked foods in order to avoid risk of infections that may be harmful to the foetus. In this case, the use of a folic acid supplement will be much more beneficial.

Who will benefit from the use of a folic acid supplement?

In certain demographics, the intake of folate through diet may not be sufficient enough to ensure adequate levels of vitamin B9. In these cases, it is recommended to add a folic acid supplement to the diet in order to prevent the onset a deficiency.

The following demographics could benefit from including a supplement in their diets:

  • Pregnant or lactating women: During pregnancy there is an increase in the nutritional requirements of vitamin B9. The introduction of a folic acid supplement will help expecting moms meet their daily recommended dose.
  • People over 65 years of age: The lack of folate in the elderly can create issues with memory and vision. The use of a supplement can keep these symptoms at bay.
  • Newborn infants (specially premature ones): If the mother's folate levels were insufficient, the newborn will need an extra intake of folic acid to avoid alterations in their growth and development.
  • strong>Intestinal ​malabsorption: Some diseases (Crohn's disease, celiac disease, ulcerative colitis) cause difficulties in the absorption of nutrients, including folate. The use of a supplement will help avoid deficiencies of this vitamin.
  • People suffering from addiction to alcohol: Although moderate consumption of beer has been shown to contribute to increased folate levels, excessive intake of high-grade alcohol (such as whisky or gin) will have the opposite effect. In these cases, it’s necessary to add a folic acid supplement to the diet.
  • Consumption of certain pharmaceutical drugs: There are drugs (anti-tumour, anti-epileptics, antimalarials, anti-rheumatics, contraceptives, diuretics and some antibiotics) with "anti-folate" activity that reduce B9 reserves in the body. In these cases, a supplement can prevent the appearance of a folic acid deficiency.
  • Metabolic​ deficits: Genetic alterations have been discovered in which the individuals capacity to absorb, activate or store folate decreases partially or totally. In these cases, the intake of folic acid (or even active forms of vitamin B9) will be essential to avoid the appearance of negative symptoms.
  • People with a cardiovascular ​pathology: Adequate levels of B9 contribute to a decrease in circulating homocysteine in the blood. This decreases the likelihood of adverse cardiac events. The use of a folic acid supplement will help to keep vitamin B9 at adequate levels supporting carfiovadscnlar health.
  • People with vitiligo and psoriasis: In most clinical studies, an extra intake of folic acid has been shown to improve the symptoms of these skin pathologies.

There are other hypotheses about the benefits of folic acid. For example, this nutrient is often recommended for people who want to improve the texture and growth of their hair. However clinical studies have not been able to prove the actual usefulness of folic acid in these situations, due to the fact that little or no improvement was observed.

Currently, the role of folic acid in the treatment of depression is also being researched. Folic acid administration showed benefits in 20% of patients treated simultaneously with B9 and antidepressants. Unfortunately, more data is needed before this promising hypothesis can be confirmed.

Nutritious different ingredients containing vitamin B9, dietary fiber, natural minerals and folic acid, healthy nutrition concept

You can find folic acid in a wide variety of foods. (Fuente: ratmaner: 105448070/

What types of folic acid supplements are there?

When it comes to supplementation, folic acid is the most popular synthetic form of vitamin B9. However, there are people who are unable to metabolise this form of the vitamin, causing folic acid to build up in the blood, which increases the risk of serious diseases (such as cardiovascular diseases and cancer).

People who can’t metabolise and activate this substance can get an adequate folate intake by taking levomefolic acid (5-MTHF) supplements. This substance is the active form of vitamin B9, capable of providing all the benefits of folate without the need for it to be metabolised in the body.

Below is a table comparing the two types of supplements:

Folic acid supplements 5-MTHF supplements
Molecular structure Artificial structure Same as natural form.
Biodavailability Very high (100-85%). Inadequate gastric pH may impair absorption. Very high (100-85%). Independent of gastric pH.
Activation Through the liver and metabolism. Not necessary, comes already active and bioavailable.
Toxicity May mask symptoms of B12 deficiency. High un-metabolised concentrations may be toxic. Does not mask symptoms of B12 deficiency. Does not accumulate in its inactive state.
Side effects Very few (hypersensitivity reactions). Described: Irritability, insomnia, muscle aches, joint pains, acne, skin irritation, anxiety, palpitations, headache, migraines.
Safety Very safe when ingested at the recommended dose. Probably safe, currently under study.

Folic acid supplements are a cheap and safe option for the majority of the population. However, people with issues metabolising it can raise their B9 levels by using levomefolic acid. If side effects occur after use, stop taking the supplement and consult your family doctor.

Joe LeechNutritionist. University of Wollongong, Australia
"[Levomefolic acid supplementation] is like taking your food home already prepared, instead starting with raw ingredients. To have a mutation of the MTHFR gene is to have no pan or pot in which to cook those ingredients."

How to take folic acid supplements?

Folic acid supplementation is very simple. The only thing that is necessary is to take one tablet with the recommended dose (between 250 and 400 mcg) once a day, preferably before breakfast. Some people may experience an upset stomach after swallowing the tablet. In that case, folic acid should be taken with meals.

Supplementation with folic acid or 5-MTHF is intended only for a limited period of time (about four months). One exception to this would be for women of childbearing age. It’s often suggested that this demographic take small amounts of B9 daily, ensuring the health of a future embryo in the event of an unplanned pregnancy.

beautiful young brunette woman with vitiligo disease

Vitiligo is a disease that produces alterations in the skins pigmentation. Supplementing with folic acid can help manage the symptoms. (Fuente: Afanasiev: 75815057/

What adverse effects can folic acid cause?

For the most part folic acid supplementation is considered safe. However, in some people minor adverse effects such as nausea, stomach pain and discomfort after taking the tablets has been reported. In these cases, taking the supplement with food or just before going to bed can often mitigate these unpleasant effects.

On the other hand, some studies have found an increased incidence of cancer and cardiovascular disease among people who took very high amounts (more than 1,000 mcg) of folic acid supplements over a long period of time. This is why experts advise never exceeding the maximum recommended dose of 1mg per day.

Moreover, some adverse effects have been described from the high intake of 5-MTHF. These symptoms include irritability, insomnia, body aches, skin irritation, anxiety and headaches, among others. These effects do not affect all individuals and there are no indicators as to whether or not someone is susceptible to these symptoms prior to supplementation.

In most cases, the nausea caused by taking a folic acid supplement reduces or completely disappears within a few weeks.

When is the use of folic acid supplements not recommended?

People with hypersensitivity to this compound are advised to exercise caution when deciding to supplement this nutrient. Furthermore, this product is not suitable for individuals with defects in folate metabolism (alterations in the MTHFR gene). For them, it is recommended they use levomefolic acid instead.

Another important contraindication for the use folic acid supplements is the presence of a vitamin B12 deficiency. In this case, the use of folic acid may mask the first symptoms of a vitamin B12 deficiency, which makes treatment and diagnosing more difficult, this in turn can increase the risk of more serious complications.

Mariana CamarenaNutritionist
"Vitamin B12 and B9 (folic acid) are essential for good mental performance."

Shopping Criteria

Choosing a vitamin B9 supplement can be complicated. Do you have any doubts between whether you should choose a folic acid supplement or a 5-MTHF supplement? Do you know whether to opt for a supplement that combines, in addition to vitamin B9, iodine and iron? Our purchase criteria will inform you of everything you need to know about these particular supplements and help you choose the one that best suits your needs:

Pharmacological interactions

Negative drug interactions with folic acid are few. Most of the time, combining a given drug with vitamin B9 will decrease the effectiveness of the supplement. If you use any of the following treatments, we advise you to discuss with your family doctor whether folic acid is the right supplement for you:

  • Anticonvulsants (medications for the treatment of epilepsy)
  • Methotrexate
  • Pharmaceuticals for the treatment of malaria

Tablets of Vitamin B complex, vitamin C, Magnesium, Zinc, minerals in brown to help reduce symptoms of stress, reduce tension, support energy production.

The tablets are easily accessible to the public, and can be found at any nearby drugstore.
(Source: Siamphotos: 103700457/

Content of 5-MTHF

Depending on your personal medical history (taking anti-epileptic drugs, genetic alterations or malabsorption pathologies), it may be beneficial to change your folic acid supplement to a 5-MTHF supplement. The active form of vitamin B9 offers all the benefits of folic acid and does not need to be metabolised by the body.

Vegan or vegetarian requirements

Fortunately, folic acid supplements are available in forms suitable for both vegans and vegetarians. If you wish to purchase a product free of animal products, make sure that the capsule coating of your supplement is of vegetable origin. Make sure to look for quality seals and to consult the list of ingredients of the product you choose.

Vegan icon design.

Folic acid supplements suitable for vegans will often have a very distinct seal on the packaging, allowing for easy recognition.
(Source: themoderncanvas: 57067475/

In the table below, you can see the recommended dosages (according to experts) for each demographic. However, remember that the optimal dosage of folic acid varies from person to person and should be adjusted individually, preferably after a visit to a your family doctor.

Population group Recommended dose
People with folate deficiency 250 mcg - 1,000 mcg
Pregnant, prevention of neural tube defects in the foetus 400 mcg
Breastfeeding women 250 mcg - 400 mcg
People with elevated homocysteine levels 200 mcg - 15,000 mcg*
People with symptoms of depression 250 mcg - 500 mcg
Age-related macular degeneration 2,500 mcg*
Individuals with vitiligo 5,000 mcg*

*High doses of folic acid require the supervision of a health care professional.

Method of administration

Folic acid supplements usually come in the form of capsules or tablets. Some tablets must be taken with water and food at the same time every day. It is also possible to find folic acid and 5-MTHF in the form of powder. This presentation is not as popular and is usually ingested and marketed to bodybuilding enthusiasts.

The recommended dose of folic acid for pregnant women can usually be found in prenatal vitamin supplements, which usually contain, in addition to vitamin B9, compounds such as iron, B12 and iodine. If you are pregnant or plan to start a pregnancy, discuss with your doctor or midwife which type of supplement will be right for you.

Eva Bermejo-SanchezArea Coordinator of the Institute for Rare Diseases - Carlos III Health Institute
"There are many ways to prevent birth defects. Important: plan your pregnancy, get vaccinated, take a folic acid supplement before you become pregnant, avoid alcohol, tobacco and drugs."

Value for your money

There is no doubt that folic acid supplements are much cheaper than 5-MTHF acid supplements. It’s a good idea to buy a bulk "savings" option, which normally contains enough product to use for three or four months. Vitamin B9 powder is more expensive, but will allow you to adjust the dosages more precisely.


Folic acid has created a revolution supporting the health of pregnant women and their children. As a prenatal supplement, it reduces the appearance of malformations of the neural tube and it ensures the birth of healthy, strong babies. However, one must not forget that this vitamin is also an indispensable compound for the overall well-being of the entire population.

We hope you found this article helpful in understanding this important nutrient. Remember that, when used in the recommended doses, folic acid is a safe and extremely useful supplement. Go one step further and combine it with a proper diet and an active lifestyle to get the most out of all its benefits.

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(Featured image source: Yemelyanov: 47531853/

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