title: Effects of dietary zinc supplement during lactation on longitudinal changes in plasma and milk zinc concentration.
abstract: Effects of dietary zinc supplement during lactation on maternal zinc plasma and milk zinc concentration through 5 months of lactation were examined. One hundred and thirty eight healthy lactating mothers received a weekly 100 mg elemental zinc supplement (ZS, n = 67) or placebo (PG, n = 71) starting one week postpartum in a double blind, randomized design. Milk and plasma zinc concentrations were determined by atomic absorption spectrophotometer. During the course of study, there was not a significantly difference between ZG and PG groups in dietary zinc and energy intake. The mean plasma zinc concentration at 1st week and 5th month were 134 +/- 49.1 and 115.6 +/- 23 microg dL(-1) (PV = 0.005) for PG group, respectively; that of the ZG group these figures were 124.9 +/- 52.8 and 121 +/- 27.1 microg dL(-1) (PV = 0.38), respectively. The mean serum alkaline phosphatase concentration at 1st week and 5th month were 94.8 +/- 37 and 92.6 +/- 29.9 iu L(-1) for PG group, respectively; that of the ZG group these fissures were 90.5 +/- 36 and 90 +/- 29 iu L(-1) (PV = 0.21), respectively. Milk zinc concentration declined significantly over the course of study for two groups, with the sharpest decline occurring during the first 2 months. The mean monthly zinc concentration of ZG group declined from 310 +/- 138 at 1st week to 118 +/- 64 microg dL(-1) at 5th month (declined by 52%). Corresponding means for PG group were 322 +/- 161 and 109 +/- 70 microg dL(-1) (declined by 60%), respectively. Milk zinc concentration significantly different between two groups at 3 and 4 months. A similar study, however, with different zinc dose and administration manner, in zinc marginal deficient lactating mothers is needed to assess the impact of zinc supplementation on milk zinc concentrations.
authors.affiliation: Shaheed Sadoughi Medical Sciences and Health Services University, Yazd, Iran.
authors.forename: Hassan Mozaffari
authors.initials: HM
authors.lastname: Khosravi
authors.forename: Beman Ali
authors.initials: BA
authors.lastname: Jalali
authors.forename: Mohamad Hassan
authors.initials: MH
authors.lastname: Eftekhari
mesh_terms: D000821:Animal Feed; D000818:Animals; D002417:Cattle; D002986:Clinical Trials as Topic; D019587:Dietary Supplements; D005260:Female; D007774:Lactation / Q000187:drug effects / Q000502:physiology*; D008892:Milk / Q000502:physiology*; D010919:Placebos; D015032:Zinc / Q000032:analysis* / Q000494:pharmacology*
chemical_list: D010919:Placebos; D015032:Zinc