The effect of calcium supplementation in pregnancy on breast milk calcium concentration

Introduction: The relationship between calcium intake during lactation and breast milk calcium concentration has been studied by many investigators, but there is no conclusive evidence on the effect of supplementation during pregnancy on the breast milk content. The aim of this double blind, placebo controlled trial was to determine the effect of calcium supplementation during the third trimester of pregnancy on the breast milk calcium concentration. Materials and Methods: Sixty-eight pregnant mothers were assigned randomly to "Calcium Supplement" (1 g daily, as two calcium carbonate capsules) or "Placebo" groups from 28th-30th week of gestation through delivery. Breast milk samples were taken 1.5-3 months after delivery. Calcium concentration was measured using atomic absorption spectrometry. Data analyses were done by SPSS (Version 9). Results: There were no significant differences between the two groups with respect to demographic characteristics, anthropometric measures, dietary energy and calcium intakes, and blood pressure. Compliance was similar between the two groups and no participant was a smoker. Mean±SD of calcium concentrations in mature breast milk were 228±38 and 235±42 mg/L in "Calcium Supplement" and "Placebo" groups, respectively (p=0.49). Conclusion: Our study did not support the hypothesis stating that calcium supplementation during the third trimester of pregnancy affects concentration in mature breast milk.