Effect of multiple-micronutrient supplementation on maternal nutrient status, infant birth weight and gestational age at birth in a low-income, multi-ethnic population

Poor nutrient intake during pregnancy can adversely affect both infant and maternal health. The aim was to investigate the efficacy of multiple-micronutrient supplementation during pregnancy in a socially deprived population in the developed world. We conducted a randomised, double-blind, placebo-controlled trial of multiple-micronutrient supplementation including 20 mg Fe and 400 mu g folic acid, from the first trimester of pregnancy in 402 mothers, in East London, UK. Nutrient status was measured at recruitment, and at 26 and 34 weeks of gestation. Infants were weighed at birth. At recruitment the prevalence of anaemia was 13%, vitamin D insufficiency 72%, thiamin deficiency 12% and folate deficiency 5%, with no differences between groups. Only 39% of women completed the study; rates of non-compliance were similar in both groups. Intention-to-treat analysis showed that participants receiving treatment had higher mean Hb at 26 weeks of gestation (110 (SD 10) v.108 (SD 10) g/l; P=0.041) and 34 weeks of gestation (113 (SD 12) v.109 (SD 10) g/l; P=0.003) and packed cell volume concentrations at 26 weeks of gestation (0-330 (SD 0.025) v. 0.323 (SD 0.026) l/l; P=0.011) and 34 weeks of gestation (0.338 (SD 0.029) v. 0.330 (SD 0.028) l/l; P=0.014) compared with controls. Analysis of compliant women showed supplemented women had higher median concentrations of serum ferritin, erythrocyte folate and 25-hydroxyvitamin D later in gestation than controls. In the compliant subset (n 149), placebo mothers had more small-for-gestational age (SGA) infants (eight SGA v. thirteen; P=0.042) than treatment mothers. Baseline micronutrient deficiencies were common; the multiple-micronutrient supplement was well-tolerated and improved nutrient status. Multiple-micronutrient supplements from early pregnancy may be beneficial and larger studies are required to assess impact on birth outcomes and infant development.