Cochrane: Maternal nutrition during pregnancy is known to have a significant effect on fetal growth and development.
In our review, regular intake of extra calcium tablets during pregnancy did not improve the number of preterm births or other infant outcomes, except for a slight increase in infant birthweight in the group of women who received calcium supplementation. Most studies included in this review were assessed as of low risk of bias, and evidence for specific outcomes was graded as of moderate quality, Taking calcium supplementation did not appear to have any obvious side effects. Our review included 25 randomised controlled studies, but only 23 studies involving 18,587 women contributed outcome data. The majority of the evidence was based on fewer numbers of studies.
In our review, regular intake of extra calcium tablets during pregnancy did not improve the number of preterm births or other infant outcomes, except for a slight increase in infant birthweight in the group of women who received calcium supplementation. Most studies included in this review were assessed as of low risk of bias, and evidence for specific outcomes was graded as of moderate quality, Taking calcium supplementation did not appear to have any obvious side effects. Our review included 25 randomised controlled studies, but only 23 studies involving 18,587 women contributed outcome data. The majority of the evidence was based on fewer numbers of studies.
Authors' conclusions:
This review indicates that there are no clear additional benefits to calcium supplementation in prevention of preterm birth or low infant birthweight. While there was a statistically significant difference of 56 g identified in mean infant birthweight, there was significant heterogeneity identified, and the clinical significance of this difference is uncertain.