Why You Need a Prenatal Multi-Vitamin With B9 - Quality for Life

Michael Roizen, MD, FACP




If you’re pregnant or thinking about getting pregnant, you probably have heard – take folic acid. That’s because folate/folic acid (also known as vitamin B9) is essential for fetal development. Your baby needs folate because it has a direct effect on DNA (1). Folate is an essential ingredient of one of the building blocks of DNA, thiamine. Without folate, your body may substitute a less effective backup building block called uracil, which can lead to birth defects, primarily spina bifida.

Spina bifida occurs when the neural tube—a structure that encases the spinal cord—doesn’t fully close. This incomplete closure can happen near the neck or the buttocks and lead to a variety of issues. Because the spinal cord forms so early on, folic acid is critical in the first six weeks of development—a time when many women might not even know they’re pregnant. 

In utero nutrients influence out-of-utero health. That is why the official recommendation of The U.S. Preventive Services Task Force (USPSTF) is “all women who are planning or capable of pregnancy take a daily supplement containing 0.4 to 0.8 mg (400-800 μg) of folic acid. (2) Ideally, you should take folic acid supplements or make sure you’re getting enough folate from food if there’s even a chance that you could become pregnant or be pregnant already.  That’s why we like you to start taking a prenatal vitamin at least three months prior to becoming pregnant—or, to be safe, during all years when you might become pregnant.

Interestingly, when Canada added folate to flour and bread to increase the country’s intake among women who might not know they’re pregnant, the country saw birth defect rates drop by more than 50 percent (3,4). You should get 800 mcg of folic acid a day; some women need extra supplementation because their bodies aren’t able to convert it to the form that’s needed for DNA production, and health care practitioners may prescribe up to four milligrams. Look for a prenatal vitamin that contains folic acid from methylfolate, as this seems to make the folate/folic acid more available.  

Research also suggests other health benefits of folic acid (if these weren’t enough), including longer gestation (so your baby will have proper time in-utero before having to brave the outside world) (5,6) and quieting the “kick.” Many pregnant women suffer from leg cramps and restless leg syndrome, which occurs when your leg reflexively spasms in a kicking motion. The problem isn’t that you risk bruising your bedmate; it’s that the motion can wake you out of a good sleep. The syndrome is also associated with that creepy-crawly sensation; your leg feels as if it’s being pinched. It seems to be caused by irregular levels of the chemical dopamine. Some treatments include making sure you get 800 micrograms of folate a day during pregnancy (400 micrograms from a prenatal multi-vitamin and 400 mcg from food or supplements) and 30 mg of iron (7). Applying a heating pad to the area also seems to quiet the disturbances. Also, magnesium (400 mgs) and calcium (1,200 mgs) can help leg cramps, as these minerals are used by muscles to contract normally (8).

For my patients who are sexually active and thinking about conceiving, I suggest they take a prenatal multi-vitamin and split it down the middle, so they take one half in the morning and the other in the evening. The body will rid itself (through urination) of water-soluble vitamins in approximately 12 to 16 hours, so this split will help to keep the nutrient levels steady in your body and in your baby’s.

Thanks for reading. Feel free to send questions—to ageprooflife@gmail.com, and some of them we may know enough to answer (we’ll try to get answers for you if we do not know). 




1. Duthie SJ, Narayanan S, Blum S, Lynn Pirie,  Brand GM. Folate Deficiency In Vitro Induces Uracil Misincorporation and DNA Hypomethylation and Inhibits DNA Excision Repair in Immortalized Normal Human Colon Epithelial Cells. Nutrition And Cancer 2009; 245-251 | Published online: 18 Nov 2009 http://dx.doi.org/10.1207/S15327914NC372_18

2. US Preventive Services Task Force, Bibbins-Domingo K, Grossman DC, Curry SJ, Davidson KW, Epling JW Jr, García FA, Kemper AR, Krist AH, Kurth AE, Landefeld CS, Mangione CM,Phillips WR, Phipps MG, Pignone MP, Silverstein M, Tseng CW.  Folic Acid Supplementation for the Prevention of Neural Tube Defects: US Preventive Services Task Force Recommendation Statement. JAMA.  2017 Jan 10;317(2):183189. doi: 10.1001/jama.2016.19438  https://www.ncbi.nlm.nih.gov/pubmed/28097362

3.De Wals P, Fassiatou Tairou F, Van Allen MI, Soo-Hong Uh M.Sc,  Lowry RB,  Sibbald B, et al. Reduction in Neural-Tube Defects after Folic Acid Fortification in Canada. N Engl J Med 2007; 357:135-142July 12, 2007DOI: 10.1056/NEJMoa067103

4. Ray JG, Meier C, Vermeulen MJ, Boss S, Wyatt PR, Cole DEC, Association of neural tube defects and folic acid food fortification in Canada. The Lancet  2002; 360, Issue 9350, 2047–2048

5. Bukowski R, Malone FD, Porter F, et al. Preconceptional folate prevents preterm delivery. Am J Obstet Gynecol, 2007; 197 (6S),  3

6. Zhanga Q, Wang Y, Xin X, Zhang Y,  Liub D, et al.  Effect of folic acid supplementation on preterm delivery and small for gestational age births: A systematic review and meta-analysis. Reproductive Toxicology 2017; 67: 35–41  

7.  Lee KA, Zaffke ME,  Baratte-Beebe K. Restless Legs Syndrome and Sleep Disturbance during Pregnancy: The Role of Folate and Iron Journal of Women's Health & Gender-Based Medicine. 2004, 10(4): 335-341. doi:10.1089/152460901750269652.

8. Dahle LO . Berg G. Hammar M, Hurtig M, Larsson L. The effect of oral magnesium substitution on pregnancy-induced leg cramps. American Journal of Obstetrics and Gynecology 1995; 173, 175-180.  https://doi.org/10.1016/0002-9378(95)90186-8

Published on

30 August 2017

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