Zinc nutritional status during pregnancy: a longitudinal study

Abstract

Dietary zinc (Zn) intake and selected biochemical indices of Zn status were studied longitudinally at monthly intervals in 46 pregnant middle-income women, 10 of whom received a daily supplement of 15 mg Zn. Mean dietary Zn intake for the nonsupplemented subjects (group A) was 11.3 +/- 4.1 mg/day (56% of the Recommended Dietary Allowances), and for the Zn-supplemented subjects (group B) was 21.7 mg/day (109% of the Recommended Dietary Allowance), including an average intake of 11.1 mg/day as supplemental Zn. The mean plasma Zn concentration of group A at 2 months gestation, 71.4 +/- 9.8 micrograms/dl, was 17% lower than that of nonpregnant control women, and continued to decline significantly (p less than 0.01) between 2 and 10 months gestation. Plasma Zn of group B did not differ significantly from group A at any stage of gestation. Mean serum alkaline phosphatase activity of group B was higher than that of group A at 7 of 8 months studied (p less than 0.05). The level of prenatal iron supplementation in group A was negatively correlated with alkaline phosphatase activity and plasma Zn in the 2nd and 3rd trimesters, respectively. It is concluded that an early and progressive decline in plasma Zn which is not influenced by Zn intake occurs during gestation. Tentative standards for lower limits of normal at monthly intervals have been suggested. The higher alkaline phosphatase activity of group B compared with group A suggested that the dietary Zn intake of the latter was suboptimal. Prenatal supplemental iron may adversely affect maternal Zn status.

Low Dietary Zinc Intake During Pregnancy and Lactation of Gilts. I. Effects on the Dam

“…The trends observed in plasma Zn andCu rn our study and elsewhere (Hambidge and Droegemueller 1974;Hambidge et al 1983;Golub et al 1984a) reinforce the suggestion that a similar mechanism(s) may be responsible for the changes in the circulating levels of both elements (Hambidge et al 1983 Hambidge et al (1983). However, Zn-deficient pregnant monkeys showed significantly reduced APA only at the end of pregnancy (Golub et al 1984a).…”

Zinc in Human Nutrition

“…(1985) supplemented low-income teenagers of Mexican descent (mean dietary intake of 10 mg Zn/d) with 20 mg Zn daily throughout pregnancy, but Zn supplementation did not affect the outcome of pregnancy compared with controls. A similar study was performed by Hambidge et al (1983) who gave a supplement of 11 mg Zn/d but found no effect on pregnancy outcome or birth weight. Tuttle et al (1 985) found no association between intravascular mass of Zn and percentilebirth-weight distribution in women taking in 9 mg Zn/d, and Campbell-Brown et af.…”

Zinc Nutrition in Developing Countries

“…For example, plasma Zn correlated weakly with birth weight when sampled at mid pregnancy (McMichael et al 1982), more strongly in early rather than in later pregnancy, i.e. third trimester (Neggers et al 1990), or not at all Buzina et al 1980;Hambidge et al 1983;Campbell-Brown et al 1985;Hunt et al 1985;Tuttle et af. 1985;Mahomed et al 1989).…”