Multivitamin Supplementation and Adequacy of Gestational Weight Gain among Pregnant Women

Gestational weight gain (GWG), a modifiable risk factor, is associated with adverse birth outcomes. Studies have shown that providing multiple micronutrient supplements to pregnant women lowers the risk of low birth weight. However, the effect of multiple micronutrient supplements on GWG remains unclear.

The present study examined the effect of daily supplementation of pregnant women with multivitamins on GWG concerning the GWG recommendation by the Institute of Medicine (IOM).

It randomized 7573 women with singleton pregnancies and gestational age between 12 and 27 wk to receive daily multivitamins or a placebo until delivery; and measured weight at enrollment and every follow-up visit. The study looked for severely inadequate (<70%), inadequate (<90%), and excessive GWG (≥125%). It calculated the percentage adequacy of GWG as actual GWG divided by the recommended GWG according to the IOM recommendation. 

The study observed-

• The mean percentage adequacy of GWG was 96.7% in the multivitamin arm and 94.4% in the placebo arm, with a mean difference of 2.3%.
• Compared with women in the placebo arm, those receiving multivitamins showed a lower risk of severely inadequate GWG and inadequate GWG. 
• No significant difference in excessive GWG.

This study shows that multivitamin supplementation can increase GWG and reduce the risk of severely inadequate and inadequate GWG among pregnant women. Together with previously reported beneficial effects of the supplements on birth outcomes in low- and middle-income countries, these findings support scaling up the use of prenatal supplements, including multivitamins along with iron and folic acid.

Liu E, Wang D, Darling AM, et al. Multivitamin Supplementation Is Associated with Greater Adequacy of Gestational Weight Gain among Pregnant Women in Tanzania. The Journal of Nutrition. 2022;152(4):1091–1098. https://doi.org/10.1093/jn/nxab448