Micronutrient supplementation programs for vitamin A, iron and folic acid, calcium, zinc, and multiple micronutrients effectively impacted the micronutrient status of pregnant and lactating women, as well as women of reproductive age and adolescent girls (13, 14, 33, 35–48). Interventions making use of multiple micronutrients were more effective at changing plasma micronutrient concentrations than interventions focused solely on 1 nutrient alone (38, 42). In countries with comprehensive programs for iron supplementation during pregnancy, anemia prevalence dropped (1, 49). Positive health impacts of supplementation were most notable among pregnant women who were deficient and at risk of low intake (43, 50). However, there were some studies that showed inconsistent or limited evidence for the effectiveness of supplementation on other maternal health outcomes (31, 51–58).
^ Jump up to: a b c Aldridge, Robert W.; Story, Alistair; Hwang, Stephen W.; Nordentoft, Merete; Luchenski, Serena A.; Hartwell, Greg; Tweed, Emily J.; Lewer, Dan; Vittal Katikireddi, Srinivasa (2017-11-10). "Morbidity and mortality in homeless individuals, prisoners, sex workers, and individuals with substance use disorders in high-income countries: a systematic review and meta-analysis". Lancet. 391 (10117): 241–250. doi:10.1016/S0140-6736(17)31869-X. ISSN 1474-547X. PMC 5803132. PMID 29137869. All-cause standardised mortality ratios were significantly increased in 91 (99%) of 92 extracted datapoints and were 11·86 (95% CI 10·42–13·30; I2=94·1%) in female individuals