Heavy Metal Index
Ask the IndexAboutIndex Pro

Zinc Concentration during Pregnancy and Lactation in Enugu, South-East Nigeria

Cite this pageVersion history

This Nigerian cohort survey measured serum zinc across pregnancy and after delivery, and zinc in breast milk over the first 15 days of lactation, in women attending three Enugu antenatal clinics. Serum zinc was lowest in the third trimester and breast milk zinc fell steadily from colostrum to day 15. The authors read the results as a call for maternal zinc supplementation and dietary improvement.

Key numbers

  • Serum zinc (mean ± SD, µg/dL): controls 109.75 ± 17.69; first trimester 106.82 ± 19.76; second 101.65 ± 14.47; third 85.57 ± 15.50; postpartum 90.66 ± 12.94 (P < 0.0001 overall) (Results, p. 72).
  • Breast milk zinc (µg/dL): day 0 to 3, 71.52 ± 4.06 (n = 10); day 4 to 6, 65.55 ± 3.74 (n = 14); day 7 to 9, 61.32 ± 3.14 (n = 19); day 10 to 12, 58.76 ± 2.73 (n = 22); day 13 to 15, 54.18 ± 3.44 (n = 15) (Table 2, p. 73).
  • Estimated daily zinc intake by 24-hour recall: 26.65 ± 7.10, 24.92 ± 6.70 and 23.43 ± 5.20 mg/day by trimester and 21.72 ± 4.90 mg/day in controls (Table 1, p. 73).
  • Of 120 pregnant women recruited, 80 completed the study (22, 31 and 27 by trimester); 35 non-pregnant controls (p. 71).

Methods (brief)

Pregnant women were randomly recruited by trimester at one tertiary and two secondary clinics in Enugu between March and December 2009; women with anemia, infection, chronic disease, or zinc supplements were excluded. Serum and expressed breast milk were analyzed by atomic absorption spectrophotometry. Dietary zinc was estimated from a single 24-hour recall and food composition tables.

Evidence fitness

The paper supports descriptive maternal serum and early breast milk zinc values for one Nigerian city. It is a nutrition-status study and does not address zinc contamination. Its cross-sectional trimester groups cannot show within-woman change through pregnancy.

Limitations

Different women were sampled in each trimester and dropout was high (80 of 120). No reference material or recovery data are given for the analysis. A single 24-hour recall is acknowledged by the authors as a possible source of bias, and the high estimated intakes sit oddly beside falling serum levels.

Update history

No substantive edit history is available in this build. The full commit record is available in git.

Referenced by