Table 3

Serum concentration distributions of select biochemical indicators for pregnant Peruvian women1
Biochemical indicator1 LOD2 Trimesters 1–3 Combined Cord serum p-values4
% of samples below LOD n GM (95% CI)3 Median (range) Min. Max. % of samples below LOD n GM (95% CI) Median Min. Max.
Retinol 0.035 0.0 193 1.43 (1.40-1.49) 1.46 0.74 2.63 0.0 52 0.64 (0.60-0.69) 0.66 0.34 1.29 ≤ 0.0001
Retinyl palmitate 0.025 65.3 193 NC5 LOD LOD 0.11 100.0 52 NC NC LOD LOD NC
Retinyl stearate 0.013 97.4 193 NC LOD LOD 0.027 100.0 52 NC NC LOD LOD NC
Alpha-tocopherol 0.94 0.0 193 27.2 (26.2-28.3) 27.9 14.3 46.0 0.0 52 5.92 (5.52-6.35) 5.80 3.60 15.5 ≤ 0.0001
Gamma-tocopherol 0.26 0.0 193 3.14 (2.98-3.32) 3.21 1.10 7.68 17.3 52 0.35 (0.31-0.39) 0.34 0.18 0.98 ≤ 0.0001
Alpha-carotene 0.013 0.0 193 0.19 (0.18-0.21) 0.19 0.042 1.14 65.4 52 NC NC LOD 0.007 NC
Beta-carotene 0.015 0.0 193 0.21 (0.20-0.23) 0.21 0.050 1.90 69.2 52 NC NC LOD 0.005 NC
Cis-beta-carotene6 0.013 23.9 71 0.018 (0.017-0.020) 0.017 0.009 0.12 100.0 31 NC NC LOD LOD NC
Beta-cryptoxanthin 0.016 0.0 193 0.43 (0.39-0.47) 0.45 0.07 2.39 0.0 52 0.052 (0.045-0.063) 0.051 0.018 0.26 ≤ 0.0001
Lutein + zeaxanthin 0.042 0.0 193 0.53 (0.50-0.58) 0.53 0.11 1.24 0.0 52 0.11 (0.10-0.12) 0.10 0.065 0.28 ≤ 0.0001
Trans-lycopene 0.015 0.5 193 0.058 (0.052-0.063) 0.054 0.011 0.53 100.0 52 NC NC LOD LOD NC
Total lycopene 0.019 0.0 193 0.15 (0.14-0.18) 0.15 0.028 1.04 94.2 52 NC NC LOD 0.050 NC
Ferritin7 6.81 0.0 192 52.1 (45.2-60.2) 52.8 6.74 528 0.0 47 321 (272–377) 315 101 1090 ≤ 0.0001
Iron 0.90 0.0 202 12.1 (11.2-13.0) 12.8 2.33 30.6 0.0 47 26.2 (24.4-28.2) 26.9 12.0 36.2 ≤ 0.0001
Unbound iron capacity 1.80 0.0 182 55.6 (52.9-58.4) 56.9 24.2 128 0.0 42 10.0 (8.09-12.6) 10.4 1.79 31.7 ≤ 0.0001
Total iron bound capacity8 N/A 0.0 181 71.3 (69.0-71.3) 70.0 34.7 134 0.0 42 38.2 (36.2-40.3) 37.5 25.1 57.7 ≤ 0.0001
Transferrin saturation9 N/A 0.0 181 17.9 (16.4–19.6) 19.0 3.0 53.0 0.0 42 67.0 (61.7–72.6) 73.5 34.0 95.0 ≤ 0.0001
Selenium 0.063 0.0 204 1.44 (1.41-1.44) 1.46 0.79 2.15 0.0 44 0.86 (0.83-0.89) 0.87 0.61 1.14 ≤ 0.0001

1All values expressed in μmol/L unless otherwise noted.

2LOD limit of detection.

3GM geometric means; 95% CI = 95% confidence interval.

4p-values are based on a t-test and compare trimesters 1–3 combined with cord serum.

5NC not calculated. No calculations were conducted on samples for which 40% or more of the values were < LOD as per CDC methodology guidelines (17). For all other samples < LOD, calculations were based upon the LOD values divided by the square root of two.

6Because of laboratory quality control issues, the total sample size for CBC is lower compared with the remaining biochemical indicators.

7Values expressed in pmol/L (1 pmol/L = 2.247 ng/ml).

8TIBC total iron-binding capacity. TIBC = IRN + UIBC.

9Transferrin saturation = IRN/TIBC. Values expressed in %. TS does not have a specified LOD.

Horton et al.

Horton et al. Nutrition Journal 2013 12:80   doi:10.1186/1475-2891-12-80

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