Folic Acid: Are We Getting Too Much?
Updated: Jan 14
If you’re planning to conceive, you would have heard about folic acid. It’s recommended that all women of reproductive age take folic acid 1 month before conceiving and for the first 12 weeks of pregnancy, as it is critical to support the development of the neural tube. I however recommend folic acid (or other activated forms) be taken 3 months before conceiving. Read on for why. You may have heard of folate, folinic acid and methyl folate and are likely confused about them. The differences between all of those words is really important to be are aware of, especially when it comes to preconception and pregnancy supplementation.
The terms ‘folic acid’ and ‘folate’ are both used to describe Vitamin B9, but they are not the same thing. Folate is a ‘natural’ form of vitamin B9 found in leafy green vegetables, whereas folic acid is the synthetic form of vitamin B9 which is found in some supplements and is added to processed and fortified foods.
Mandatory folic acid fortification was introduced in Australia in 2009 as a public health initiative to reduce the instance of neural tube defects in infants. The fortification of bread and cereal products has had positive effect on reducing the rates of neural tube defects. However, as research continues to develop, there is now evidence that too much folic acid may block the action of the natural form folate, as well as masking B12 deficiencies.
Folic acid is not an active nutrient and therefore needs to be converted (or changed) into an active form to enter the biochemical process within the body called the methylation cycle. The methylation cycle is a metabolic process that regulates the conversion of methionine to homocysteine, DNA methylation as well as in the cardiovascular, neurological, reproductive, and detoxification systems. The methylation cycle is happening all the time without us even thinking about it, but sometimes it doesn’t work as optimally as it could. This can be for a few different reasons but is most commonly due to genetic factors referred to as small nucleotide polymorphisms or ‘SNPs’. This means for some people, their methylation cycle may be slower or inhibited to some degree. An example of this is people who are homozygous for the MTHFR (methyl-tetra-hydro-folate reductase) SNP and these people should be taking methyl folate and not folic acid. There are other methylation cycle SNP’s and looking at it all as a whole rather than just one in isolation is important to get an overall picture of methylation functioning.
The current dietary guidelines set by the Australian National Health and Medical Research Council have set the following guidelines for folate and folic acid intake:
Due to the majority of the population consuming a diet that is high in processed grain products and lower in plant-based foods, most are getting more folic acid than folate each day. The problem is that some fortified foods, in particular, breakfast cereals can contain nearly a day’s worth of folic acid. The combination of fortified foods and a multivitamin you can easily surpass the recommended upper limit. That’s a lot to process, even for those of us who have optimal functioning methylation cycles. The latest research is showing that while we still need folate and folic acid supplementation still has a place, we need to mindful of how much we are having and the potential consequences.
Women who are in the preconception and pregnancy period should be opting for supplements that contain an activated form of folate, such as folinic acid. Folinic acid is similar to folic acid in that it is synthetic, however, it is pre-activated, meaning that it bypasses the step in the conversion to the active form inside the body. Basically, this means that it can easily join the methylation cycle, with less concern of it building up. For this reason, folinic acid is commonly used in higher-quality practitioner supplements. In addition to providing an easily utilised form of folate, taking a good quality supplement will also ensure you are getting a balance of other B vitamins, especially vitamin B12 as they work in synergy with B9 within the methylation cycle.
So, what’s the take home?
Choose high quality, practitioner-only prenatal and pregnancy supplement containing an activated form of B9 (folinic acid or methyl folate, if heterozygous for MTHFR SNP).
Consume foods that are high in natural sources of folate (leafy greens and legumes).
If you are taking a supplement that contains folic acid, be mindful of your intake of foods fortified with folic acid (breads, pasta, grains).
If you are concerned about genetic SNPs or have elevated blood homocysteine, reach out to a practitioner who can support you through your pregnancy.
Know your B12 status. I aim for a serum B12 >500, though a "normal range is considered to be 300-800ng/L, though this test isn't very sensitive. MMA (methylmalonic acid) is a more sensitive marker for B12 status.
Folate=natural, folic acid= synthetic, folinic acid= "activated" version of folic acid and is more bioavailable.
Nrv.gov.au. (2019). Folate | Nutrient Reference Values. [online] Available at: https://www.nrv.gov.au/nutrients/folate [Accessed 14 May 2019].
Publishing, H. (2019). Folic acid: Too much of a good thing? - Harvard Health. [online] Harvard Health. Available at: https://www.health.harvard.edu/newsletter_article/Folic_acid_Too_much_of_a_good_thing [Accessed 14 May 2019].
Crider KS, Yang TP, Berry RJ, Bailey LB. Folate and DNA methylation: a review of molecular mechanisms and the evidence for folate's role. Adv Nutr. 2012;3(1):21–38.[Accessed 16 May 2019]