Some multivitamin supplements can help women conceive faster

Multivitamin supplements that contain folic acid and iodine may be beneficial to women who are planning to get pregnant, as reported in a study from Singapore.

“In this prospective preconception cohort study that included 908 community-recruited women … preconception micronutrient supplementation [(specifically folic acid and iodine supplements)] was associated with better fecundability and shorter time to pregnancy (TTP) of approximately one menstrual cycle,” according to the investigators.

“Evening primrose oil, on the other hand, was associated with poorer fecundability and slightly longer TTP,” they added.

The investigators attributed the beneficial effects of folic acid on fertility to the micronutrient’s involvement in reducing homocysteine levels in the body. There is evidence to suggest that increased concentrations of homocysteine can induce oocyte maturity, endothelial inflammation, trophoblast apoptosis, and oxidative stress. [Hum Reprod 2005;20:1521-1528; Hum Reprod Update 2010;16:80-95; N Engl J Med 2006;354:1567-1577; Biol Reprod 2003;69:1129-1134; Adv Nutr 2021;12:2372-2386]

Meanwhile, iodine, a key component of thyroid hormones, has the potential to regulate ovulation, promote oocyte fertilization, and aid in embryo implantation—all of which indirectly increase fertility, they added. [Hum Reprod 2021;36:265-274]

Study details

The study was conducted at KK Women’s and Children’s Hospital. Of the 908 women included, 613 had taken some form of supplements in the past 3 months before recruitment (preconception period) while 295 did not. All of them had been attempting to conceive over a median of 1.0 cycle prior to study entry.

Women who did vs did not take supplements were more likely to be ≥35 years of age (16.6 percent vs 10.8 percent), of Chinese ethnicity (78.8 percent vs 58.0 percent), nulliparous (70.8 percent vs 54.9 percent), have normal body mass index (50.2 percent vs 38.0 percent), have no smoking exposure (80.3 percent vs 69.8 percent), have consumed alcohol in the past 3 months (52.2 percent vs 36.9 percent), and have lower total daily energy intake (1,918 vs 2,020 kcal). There were no between-group differences in cycle regularity and cycle length. [Nutrients 2022;doi:10.3390/nu14235110]

Over 1 year of follow-up, a total of 387 women (42.6 percent) conceived spontaneously, with conception occurring within six and 12 cycles of follow-up in 268 (29.5 percent) and 369 (40.6 percent) women, respectively.

Discrete-time proportional hazard modelling showed that fecundability was higher with folic acid (fecundability ratio [FR], 1.26, 95 percent confidence interval [CI], 1.03–1.56) and iodine (FR, 1.28, 95 percent CI, 1.00–1.65) use but lower with evening primrose oil supplement use (FR, 0.56, 95 percent CI, 0.31–0.99) relative to nonuse.

In terms of TTP, pregnancy occurred considerably sooner with preconception folic acid (8.70 vs 9.61 cycles; p=0.004) and iodine supplementation (8.25 vs 9.33 cycles; p=0.010) but nonsignificantly longer with evening primrose oil use (9.86 vs 9.11 cycles; p=0.316) as opposed to nonuse.

Multivitamins for preconception supplementation

“To our knowledge, this is the only multi-ethnic Asian cohort that comprehensively evaluated various types of micronutrient supplements, including evening primrose oil, on fecundability in women planning pregnancy,” the investigators said.

“Our findings suggest that women who are trying to conceive could potentially benefit from taking multivitamin supplements containing folic acid and iodine. However, the exact dosage remains to be elucidated,” they added.

With supplements being widely accessible to the general population, the investigators believe that multivitamins may be a more practical option than multiple pills of different single vitamins, as multivitamins have the potential to increase compliance with preconception supplementation. [Clin Ther 2015;37:e95-e96]

“Leveraging on the global trend of increasing health consciousness and willingness to consume micronutrient supplements, the recommendation of appropriate preconception supplements might have a profound impact on fertility rates worldwide. However, the emphasis in preconception nutrition should be on a healthy and well-balanced diet, with micronutrient supplementation acting as an adjunct to optimize micronutrient reserve and improve fecundability,” they said. [Ann Intern Med 2019;170:604-613]