All About Folate
Why Folate?
Folate is a B vitamin, vitamin B9 specifically. It is one of the most supported vitamins to consume prior to and during pregnancy due to its role in helping to prevent neural tube defects. The neural tube closes around day 28 and eventually becomes the brain and spinal cord. That’s only 4 weeks into pregnancy!
Folate is also needed to help produce blood cells, is needed for DNA replication and helps to make proteins in our body. Consuming enough folate can also help lower the risk of congenital heart defects and oral clefts. So, folate is kind of a big deal.
About Folate
There are many different forms of this B vitamin. The word folate is generally used for all of the different forms. Without getting too far into biochemistry and genetics, I want to focus on natural folate, found in food, and the synthetic version, folic acid.
Folic acid is the most common form used in supplements and fortified foods. Fortified foods include, but are not limited to flour, rice, pasta, bread and breakfast cereal. These products usually have “fortified” on the label and have folic acid listed in the ingredients.
Folic acid is said to be more bioavailable (more is absorbed by the body) than food folate. This is true, the body absorbs folic acid efficiently. BUT, before the folic acid can be used it must be converted into the active form. Meaning, the body absorbs the folic acid and then it has to go through various chemical processes to turn it into the active or usable form. The problem is that about 40-60% of the population has difficulty converting folic acid into the active form. Individuals that cannot complete this conversion have a genetic variation that causes an enzyme called MTHFR (5,10-methylenetetrahydrofolate reductase) to not work properly.
If you are curious to find out if you have this variation, ask your doctor or healthcare professional about genetic testing. If you know you have this genetic variation or do not know and want to be cautious, try avoiding most folic acid fortified foods and supplements. Instead look for folate supplements with either folinic acid or L-methylfolate. L-methylfolate is also seen as L-5-MTHF or L-5-methyltetrahydrofolate or 6(S)-L-methyltetrahydrofolate.
Maternal Needs
The RDA (recommended daily allowance) for folate is 600 mcg during pregnancy. The tolerable upper limit for “folic acid” is 1000 mcg.
What does the research say
There is some compelling research on the harms of consuming too much folic acid. Consuming too much folic acid may mask or hide B12 deficiency. Consuming too much folic acid may also overload the body and reduce its effectiveness.
One study found higher insulin resistance in children born to mothers with high folate levels during pregnancy. Another study found maternal doses of folic acid exceeding the tolerable upper limit during pregnancy were associated with lower cognitive development in children aged 4-5 years old.
To put this into perspective, the tolerable upper limit for “folic acid” is 1000 mcg. For example, if you have a bowl of Kellogg’s Special K (1 cup = around 400 mcg) for breakfast, then a luna bar or a powerbar (each are 400 mcg) for a snack, plus your prenatal with folic acid, you are already exceeding the upper tolerable limit.
Many of these findings need further research, but it still seems alarming. Even if you do not trust any of these studies, it is beneficial to eat whole foods rather than foods that require fortification. Natural folate, found in foods, has not been associated with adverse outcomes.
Examples of Folate rich meals:
Crab cake with 3 oz. crab, 4 spears of asparagus, ½ cup cooked spinach, ½ orange. This meal contains around 270 mcg folate.
Vegetarian/Vegan: 1 cup cooked lentils, ½ cup cherry tomatoes, ½ cup diced bell pepper, ¼ cup diced onions. Top with dressing of your choice or try fresh lemon, brown mustard, garlic and extra virgin olive oil blended together. Serve over 1 cup shredded, thoroughly washed romaine lettuce. This meal contains around 445 mcg folate.
Food sources of folate
As with any nutrient, remember not all foods have exactly the amount of the nutrient listed. Variations in climate, soil quality and cooking can affect the levels of nutrients in foods. Also, your body will likely not absorb 100% of a nutrient listed for each food. Consuming more than the recommended daily allowance in food form can help protect you from deficiencies.
Information obtained from NIH Office of Dietary Supplements
References:
Chandler AL, Hobbs CA, Mosley BS, et al. Neural tube defects and maternal intake of micronutrients related to one-carbon metabolism or antioxidant activity. Birth Defects Res A Clin Mol Teratol. 2012;94(11):864-874. doi:10.1002/bdra.23068
Obeid R, Holzgreve W, Pietrzik K. Folate supplementation for prevention of congenital heart defects and low birth weight: an update. Cardiovasc Diagn Ther. 2019;9(Suppl 2):S424-S433. doi:10.21037/cdt.2019.02.03
Greenberg JA, Bell SJ, Guan Y, Yu YH. Folic Acid supplementation and pregnancy: more than just neural tube defect prevention. Rev Obstet Gynecol. 2011;4(2):52-59.
Krishnaveni GV, Veena SR, Karat SC, Yajnik CS, Fall CH. Association between maternal folate concentrations during pregnancy and insulin resistance in Indian children. Diabetologia. 2014;57(1):110-121. doi:10.1007/s00125-013-3086-7
Valera-Gran D, Navarrete-Muñoz EM, Garcia de la Hera M, et al. Effect of maternal high dosages of folic acid supplements on neurocognitive development in children at 4–5 y of age: the prospective birth cohort Infancia y Medio Ambiente (INMA) study. OUP Academic. https://doi.org/10.3945/ajcn.117.152769. Published July 19, 2017. Accessed November 1, 2020.
Office of Dietary Supplements - Folate. NIH Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/Folate-HealthProfessional/. Published June 3, 2020. Accessed November 1, 2020.