Folic Acid or Vitamin B9

Restless legs sometimes arise as a result of a lack of something. In this case it is called secondary RLS. Apart from a deficiency of iron, magnesium or vitamin B12, there may be a deficiency of folic acid. Folic acid is also known as vitamin B11. In some countries it is not called vitamin B11 but vitamin B9.

Folic acid deficiencies are more likely to develop during pregnancy, because you then need more of it for the unborn child. This also applies to the period that women are breastfeeding. That is why women during this phase of life more often suffer from restless legs, as well as leg cramps.

A friend of mine pointed me to vitamin B11. I had to search in Google before I saw that this is the same as folic acid. This friend knows a lot about orthomolecular medicine. She had read about a possible connection between vitamin B11 and restless legs. She also wondered whether there is a connection with intermittent claudication.

In this blog I further explore this topic. I deal with the following questions:

  1. What is folic acid?
  2. Is there a link between folic acid and restless legs?

What is folic acid

Folic acid is a water-soluble vitamin also known as vitamin B11 or vitamin B9. It is converted in the body into the active form folate. You need folic acid for growth, the immune system and for the production of white and red blood cells. With a (severe) deficiency, there is a greater risk of anemia, intestinal disorders, fatigue and birth defects.

You should get enough folic acid through your diet. Leafy vegetables are the richest source of this vitamin. It is mainly found in green vegetables, wholemeal products, dairy, eggs and bread. You don’t get too much of it through food. That’s because folic acid is water soluble. As a result, it is not so easily absorbed by the body.

The recommended daily allowance for an adult is 300 micrograms per day. Pregnant women or women trying to conceive are often advised to take extra folic acid. Only through food you do not get enough of it. The recommended daily allowance during pregnancy is 400 micrograms per day. This amount also applies to breastfeeding women. Folic acid is important for the construction of the nervous system of the unborn child. It also prevents birth defects.


You have to be more careful with extra folic acid via supplements. These supplements contain a different variant of the vitamin than in food, namely folate. This variant does not need to be released such as from food. A vitamin B11 supplement works directly and can be used directly by the body.

The Health Council has set an upper limit for folic acid from supplements. This has a maximum of 1000 micrograms per day for an adult. That is more than three times the recommended daily amount. An even higher dose than 1000 micrograms per day can cause gastrointestinal complaints or skin problems.

There are also reasons other than pregnancy for taking a vitamin B11 (or vitamin B9) supplement. For example, side effects of certain medicines sometimes lead to a shortage of this vitamin. Certain intestinal diseases also hinder the absorption of folic acid. Too much alcohol or a one-sided diet can be a reason to take extra folic acid as well. It is important to ensure that you get enough vitamin B12 when taking this supplement.

Folic acid and restless legs

I don’t think I have a shortage of folic acid. I get a lot of it through food. I eat more than a pound of vegetables every day, much of which are green vegetables. Part of it I steam and part of it I eat raw. I also eat dairy, eggs and whole grains. I do not use medication. I don’t drink alcohol and I don’t have a bowel disease. Besides, I’m not pregnant.

The friend who asked me if I had ever thought of a possible folic acid deficiency also mentioned intermittent claudication as a possible link. I already knew that this is more often confused with restless legs. However, it is really something else. I can well imagine that my friend does not know all this exactly.

Recently, however, I was in touch with an online compression stocking store. Via the chat I asked an employee a question about the use of compression stockings for restless legs. From the answer she gave me, I inferred that she saw RLS as the same as display legs. I found this quite disappointing and could not take her advice seriously afterwards.

Blood test

I think it may be worthwhile for me to have a blood test at the doctor in the future. With a blood test it can be checked whether I might have a folic acid deficiency. Such a deficiency can also be a hereditary issue, in the case of primary RLS. Blood tests for other deficiencies, such as iron and magnesium, are another option and I could have it done right away.

I am not someone who goes to the doctor quickly. I prefer to read about it first. Fellow sufferers are also a source of information for me. However, sometimes it is good to just have something tested. Measuring is knowing. I always keep in mind that such a test is a snapshot. I like to remain alert to what exactly the GP measures and on which basis he or she draws conclusions. As far as I am concerned, Western medicine is not the only one with a right to exist. Other health theories also provide valuable insights.

2 thoughts on “Folic Acid or Vitamin B9”

  1. Hey Sylvia!

    Leuk artikel! Ik heb er zeker wat van opgestoken. Ik ben momenteel op zoek naar een foliumzuursupplement omdat ik zwanger probeer te raken en kwam zo op jouw website terecht. Heb je toevallig ook een suggestie over welk supplement van foliumzuur je zou gebruiken? Ik heb al wat research gedaan, maar ik weet niet zo goed waar ik op moet letten. Kan jij me verder helpen?


    • Het hangt een beetje af van hoeveel je te besteden hebt, Valentine. Ik vermoed dat er meer supplementen foliumzuur zijn die goed zijn. Zelf slik ik het niet. Volgens mij kun je via verschillende websites met dat soort producten wel wat meer informatie vragen. Succes!

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