Do multivitamins help to reduce risks in pregnant women and infants in high-income countries?

The supply of sufficient micronutrients in the first 1000 days of life is crucial for a healthy physical and mental development of the child. Pregnant women in high-income countries, unlike in poorer countries, are almost always provided with micronutrient-rich foods. Nevertheless, even in high-income countries malnutrition may still occur due to poverty and a lack of knowledge about the quality of nutrition, especially in disadvantaged neighborhoods.

A recent study suggests that multivitamin supplements may be the drug of choice in this situation. Based on literature reviews from 35 studies, Danish scientists describe the extent to which risks could be reduced in 98,926 pregnant women and their babies with the help of multivitamin preparations (1).

Results:
Compared to mothers who did not use multivitamins during pregnancy, mothers who supplemented with vitamins and minerals unfortunately did not observe significant differences in premature birth rates and trisomy in their babies (2). However, it was possible to see a decreased likelihoods of
– reduced growth of the fetus by as much as 23%
–  too low birth weight by up to 21%
– neural tube defects (eg. spina bifida) by up to 33%
– cardiovascular defects by up to 27%
– urinary tract defects by up to 40%
– malformations of limbs up to 32%
 

Based on this, the Danish experts advocate the careful use of multivitamins during pregnancy in high-income countries. At the same time, they point out that additional high-quality studies are needed to make more differentiated recommendations. Transferability of these study results to low-income countries should be treated with caution. Above all, it is important to prevent the fallacy that vitamin supplements could replace a healthy diet. Instead, pregnant women, in consultation with their gynecologist, should specifically cover deficiencies in critical vitamins and minerals, such as iron and iodine, if needed. Supplementation with folic acid is recommended before pregnancy, during planning phase, because the neural tube defects mentioned above can best be counteracted by adequate coverage of the folic acid requirement at the time of conception.

Read more:

(1) HT Wolf et al. Multivitamin use and adverse birth outcomes in high-income countries: a systematic review and meta-analysis. Am J Obstet Gynecol. 2017 Oct;217(4):404.e1-404.e30. doi: 10.1016/j.ajog.2017.03.029, available at http://www.ajog.org/article/S0002-9378(17)30467-2/fulltext 

(2) Ibid. complete overview in a chart, available at http://www.ajog.org/action/showFullTableImage?isHtml=true&tableId=tbl1&pii=S0002937817304672