How much folic acid to I need before getting pregnant?

The link between folate (or folic acid) and healthy pregnancy outcomes is widely accepted and most women will be advised to take folate when their pregnancy has been confirmed. However, the timing for supplementation is key, and research shows that it is best to start as early as possible, and ideally before conception. Indeed, the NHS recommend that you start taking 400 micrograms of folic acid as soon as you start trying for a baby, or ideally for three months before, to ensure that you have adequate levels when you do fall pregnant.

While we do get some folate from diet, predominantly from green leafy vegetables such as broccoli, kale and spinach (folate is derived from the term “foliage”!) in a large percentage of the population, intake from food is insufficient to support health, and certainly to support the growth and development of a baby. It should also be noted that absorption can be affected by certain medications such as aspirin and antacids, and that much of the folate in these foods is lost through preparation and cooking – so supplementation is certainly recommended prior to conception to ensure adequate levels.

Folate is part of the water-soluble ‘B-Complex’ vitamins and is necessary for proper brain function as it is concentrated in the spinal and extra cellular fluids. Folate plays an important role toward the production of RNA and DNA as it helps in the formation of red blood cells and nucleic acids. In terms of the health of the developing foetus, folate can help to prevent birth defects including serious neural tube defects (NTDs) such as spina bifida – a condition that could result in multiple surgeries, paralysis or long-term disability. Normally the neural tube develops into the spinal cord and brain by 28 days after conception – but if the neural tube doesn’t close correctly, NTDs can occur, and supplementing with folate has been shown to increase the maternal folate status, which contributes to the reduction in risk of NTDs.

While the advice is to supplement with folate up to 12 weeks of pregnancy, there is evidence to suggest that continuing to supplement throughout pregnancy could give additional health benefits to your baby. For example, supplementation with multivitamins containing folic acid during pregnancy could significantly lower preeclampsia risk and may have beneficial effects on the neurodevelopment of children beyond its proven effect on NTDs. A review of the evidence also points to a positive association between maternal folate supplementation and a decreased risk of congenital heart defects.

It is important to note that not all folate supplements are created equally. Methylfolate (also known as 5-MTFH, L-Methylfolate and 5-methyltetrahydrofolate) is the most stable, safe and bioeffective form of folate, that can be used immediately by the body without the need for conversion – and the ideal form for pregnant women or women planning a pregnancy. This is a natural folate form, and very different in structure and function to isolated folic acid, the most common supplemental form which does not occur naturally in food.

Isolated folic acid is converted to the active methylfolate in the body, but often this process is inefficient and un-metabolised folic acid remains in the body, which can be detrimental to health. Research has established that up to 40% of the population have a mutation on their MTHFR gene, resulting in an enzyme deficiency that prevents the efficient conversion of folic acid to methylfolate – the required biologically active form – and in these individuals, taking folic acid will not effectively raise folate levels. Without testing, we cannot know who has this genetic mutation, so we advise that all women planning a pregnancy or who are pregnant choose a pregnancy multivitamin containing 400mcg of methylfolate.