Today’s post in our series on lifestyle & fertility focuses on vitamins and supplements. Taking vitamins and supplements in preparation for fertility treatment is something that we can control and that’s easy to do. But what’s been shown to help fertility outcomes? What has been tested but shown no or inconclusive results? We’ll discuss folic acid, vitamin D, and antioxidants below – some of the results surprised us. As usual, ask your doctor prior to your treatment for their recommendations and guidance, as they may be aware of even more recent unpublished research.
Folic acid has long made a name for itself for its role in helping form the neural tube and preventing major birth defects of the brain and spine. That’s why the CDC recommends taking 400 micrograms a day of folic acid for at least a month before trying to conceive. Folic acid has also been shown to lead to higher birth rates in two different studies: One such study compared pregnancy rates between women hoping to conceive (who’d been trying unsuccessfully for 36 months) and split them into a group that received supplements containing folic acid, and a group that took placebo pills. After 3 months of taking the supplement/placebo, 1/3 of the women in the folic acid group were pregnant, and none in the placebo group were (however, the sample size was small). A second study compared live birth rates among women in the general population in Hungary who either took folic acid or a placebo pill on a daily basis. Over a period of 14 months, significantly more women in the folic acid group gave birth, though the effect was relatively small.
Similarly, 232 fertility patients at Mass. General Hospital took low or high levels of folate supplements during fertility treatment, and those with higher levels of folate intake (<400 micrograms/day vs. >800 micrograms/day, i.e. more than double the CDC’s recommendation!) had significantly higher rates of implantation, pregnancy, and live birth. Several studies have also associated folic acid intake with higher sperm count and motility after 3 months of taking the supplement.
Unlike folic acid, the effectiveness of Vitamin D supplements has been called into question, with studies showing no connection between Vitamin D levels and rates of natural conception. However, when comparing women who had normal, low, and very low levels of Vitamin D who were undergoing reproductive treatment, researchers found that over 50% of the 500 participants had very low levels of Vitamin D and were slightly less likely to have a baby following treatment compared to those with low and normal levels of Vitamin D.
The research on antioxidants and fertility is the least strong at this point – researchers recently pulled together all existing studies on women and concluded that there is “very low-quality evidence to show that taking an antioxidant may provide benefit for subfertile women, but insufficient evidence to draw any conclusions about adverse events.” Their conclusions for men taking antioxidants were similar – while they may improve outcomes for fertility treatment, it’s still unclear if certain antioxidants are more effective than others.
To summarize, folic acid has the strongest evidence for a positive effect on fertility and pregnancy outcomes for both women and men. Testing your Vitamin D levels also sounds like a good idea, to make sure you’re not significantly deficient. When it comes to antioxidants, the research on their effectiveness is low quality, though taking antioxidants also seems to have no adverse effects. Keep in mind that most of this research on supplements did not identify particular mechanisms affecting fertility outcomes (except for folic acid’s role in the formation of the baby’s neural tube), making it hard to say at what stage of fertility treatment their intake is most helpful.