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Can You Take Too Much Folic Acid?

Having spent over two years trying to get pregnant, I spent a lot of time doing research, and I am sharing what I found out.

Who Should Take Folic Acid?

Folic acid is the one vitamin that it is recommended that you take if you are trying to get pregnant or in fact you have found out that you are pregnant. It is essential to take it to reduce the risk of neural tube defects in the baby. These defects can form very early on in the development of the foetus so it is key that folic acid or folate is taken as soon as possible in the pregnancy*.

When I was trying to get pregnant I did a lot of research into folic acid, how much you should take, how much is too much folic acid and what foods provide us with folic acid?

The results have been quite interesting, as well as occasionally conflicting.

Folic acid is generally known as a supplement that women of childbearing age should take. What I didn't know before this research was that meant everyone of childbearing age and not just those who were trying to have a baby.

One of the reasons for this is that, in the US, it was reported that 49% of pregnancies were unplanned in 2006**. That is a figure that I was surprised about for one. I never really imagined that that many people would have unplanned pregnancies. It seems that the majority of the unplanned pregnancies were in the younger age groups, which you would expect, but there are still a lot of unplanned pregnancies of women in their 30s.

Therefore this makes it pretty important to take folic acid even if you are not planning on becoming pregnant.

* The CDC recommends 400mcg of folic acid a day for women of childbearing age.

** Unintended pregnancy in the United States: Incidence and disparities, 2006 Lawrence B. Finer and Mia R. Zolna, 2011

If you are thinking of becoming pregnant you should take folic acid.

If you are thinking of becoming pregnant you should take folic acid.

Why Do We Need Folic Acid Anyway?

The reason that we need folic acid is to help prevent neural tube defects in babies - for example spina bifida. Research has shown that if we take the recommended dose of folic acid before and during pregnancy, the chances of having a child with a neural tube defect are reduced by as much as 70%*.

And don't forget that as well as the woman taking folic acid, it is important that the man takes folic acid too, before conception, to aid the quality of the sperm. Also children need a daily dose of folate but that can mostly be got from eating fortified cereals etc so it is unlikely that they will need and additional folic acid supplement.

* Cavalli P. Prevention of neural tube defects and proper folate periconceptional supplementation. J Prenat Med. 2008;2:40–1. [PMC free article] [PubMed]

Folic Acid Dose

So the recommended dose of folic acid for pregnant women or women of child bearing age by the CDC is 400 micrograms. The US Preventative Services Task Force recommends a dose of between 400 and 800 mcg.

It is recommended that folic acid is taken as a supplement as it is not expected that most people will be able to get this much folic acid (or folate as it is in its natural form) from their diet.

The recommended upper level for folic acid intake is 1,000 micrograms*, although some people, particularly those who have had a pregnancy that has resulted in a neural tube defect, plus others who may suffer from a folate deficiency or other medical issues, may need a daily dose of 5mg of folic acid**.

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Most often this kind of level is recommended by a doctor and you will need to get a prescription for it as you often can't pick it up at this level from a pharmacy. Also, some women who have had multiple miscarriages are prescribed 5mg of folic acid as this can help in some circumstances to lead to a full term pregnancy.

* The National Institutes for Health specifies a tolerable upper intake level for those age 19+ of 1,000 mcg

** Identifying women who might benefit from higher doses of folic acid in pregnancy - Deborah Kennedy and Gideon Coren

Foods Containing Folic Acid

There are two types of food that contain folic acid - there are those that have a natural source of folate and those that have been fortified by folic acid.

Actually a lot of foods seem to have folic acid added to them. On a quick look round my kitchen I found all of the cereals, marmite and milkshake powder had folic acid added. The fortification of flour in the US, Canada and other places started in 1997 and this led to a decrease of around 50% in neural tube defects*.

There are plenty more foodstuffs that have been fortified with folic acid (and other vitamins). Added to that you can get a good supply of folate from, in particular, leafy green vegetables. - for example you can get around 60mcg of folic acid from 2 florets of broccoli, or a helping of Brussels sprouts. So if you eat a lot of foods that are rich in folic acid then you will get a good intake but are unlikely to eat an excess of folic acid or folate.

* Incidence of open neural tube defects in Nova Scotia after folic acid fortification - Vidia L. Persad, Michiel Hof, Johanne M. Dubé, and Pamela Zimmer

Broccoli is a great natural source of folic acid.

Broccoli is a great natural source of folic acid.

Trying for a Baby?

If you are trying for a baby then you should definitely be taking folic acid tablets. You only need to take 400 micrograms a day unless you have been advised otherwise by your doctor.

Folic acid tablets are very cheap so there is really no excuse for not taking them and often they are given out free if you are in a particularly difficult situation. Folic acid tablets are very small and easy to swallow too for those people who have difficulty taking tablets.

As soon as I started thinking about having a baby I bought these really cheap folic acid tablets and took one a day. The whole bottle will last more than six months and only costs a few dollars. Once I became pregnant I switched to a prenatal vitamin which also included 400mcg of folic acid.

© 2011 Jackie Grant


Jackie Grant (author) from UK on May 12, 2011:

Thanks kafsoa

kafsoa on May 12, 2011:

Good information! rated up and useful:)

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