TABLE 1.
Baseline characteristics of mothers and their children enrolled in a trial of zinc and multivitamin supplementation1
| Zn+MVs (n = 602) | Zinc only (n = 596) | Multivitamins only (n = 598) | Placebo (n = 604) | P | |
| Maternal characteristic | |||||
| Age, y | 26.1 ± 5.02 | 26.8 ± 5.1 | 26.2 ± 5.0 | 26.5 ± 5.0 | 0.049 |
| Formal education, n (%) | 0.538 | ||||
| None | 9 (1.5) | 8 (1.4) | 10 (1.7) | 9 (1.5) | |
| 1–7 y | 441 (73.4) | 421 (71.1) | 416 (70.2) | 453 (75.3) | |
| ≥8 y | 151 (25.1) | 163 (27.5) | 167 (28.2) | 140 (23.3) | |
| Employment, n (%) | 0.125 | ||||
| Housewife without income | 357 (59.8) | 365 (62.3) | 337 (56.7) | 386 (64.4) | |
| Housewife with income | 201 (33.7) | 175 (29.9) | 212 (35.7) | 176 (29.4) | |
| Other | 39 (6.5) | 46 (7.9) | 45 (7.6) | 37 (6.2) | |
| Marital status (married or living with partner), n (%) | 542 (90.5) | 534 (90.5) | 542 (91.4) | 537 (90.0) | 0.860 |
| Previous pregnancy, n (%) | 0.378 | ||||
| None | 187 (31.2) | 169 (28.6) | 205 (34.5) | 184 (30.6) | |
| 1–4 | 396 (66.1) | 410 (69.3) | 375 (63.1) | 398 (66.2) | |
| ≥5 | 16 (2.7) | 13 (2.2) | 14 (2.4) | 19 (3.2) | |
| Midupper arm circumference, cm | 26.7 ± 3.2 | 27.1 ± 3.1 | 27.1 ± 3.1 | 27.0 ± 3.1 | 0.090 |
| Socioeconomic characteristic | 0.925 | ||||
| Daily food expenditure per person in household <1000 Tanzanian shillings,3 n (%) | 170 (29.4) | 162 (28.6) | 164 (28.8) | 158 (27.6) | |
| Household possessions,4 n (%) | 0.292 | ||||
| None | 180 (30.0) | 192 (32.7) | 173 (29.2) | 171 (28.4) | |
| 1–3 | 339 (56.5) | 308 (52.4) | 330 (55.7) | 358 (59.5) | |
| ≥4 | 81 (13.5) | 88 (15.0) | 90 (15.2) | 73 (12.1) | |
| Child characteristics | |||||
| Age at random assignment, wk | 5.9 ± 0.4 | 5.9 ± 0.4 | 5.9 ± 0.4 | 5.9 ± 0.4 | 0.543 |
| Sex, M, n (%) | 289 (48.0) | 300 (50.3) | 316 (52.8) | 311 (51.5) | 0.388 |
| Low birth weight (<2500 g), n (%) | 22 (3.7) | 21 (3.6) | 21 (3.6) | 18 (3.0) | 0.920 |
| Born preterm (<37 wk),5 n (%) | 67 (12.1) | 80 (14.6) | 66 (12.0) | 77 (14.0) | 0.501 |
| Small for gestational age5,6 | 53 (9.9) | 48 (8.9) | 35 (6.5) | 55 (10.1) | 0.143 |
| z score7 | |||||
| Length-for-age | −0.37 ± 1.23 | −0.33 ± 1.19 | −0.26 ± 1.20 | −0.17 ± 1.31 | 0.028 |
| Weight-for-length | 0.15 ± 1.31 | 0.16 ± 1.33 | 0.14 ± 1.29 | 0.05 ± 1.28 | 0.477 |
| Weight-for-age | −0.26 ± 1.02 | −0.23 ± 0.97 | −0.17 ± 0.99 | −0.16 ± 1.05 | 0.247 |
1
P values for continuous variables were derived from ANOVA tests. P values for categorical variables were derived from chi-squared tests. Zn+MV, zinc and multivitamin.
2
Mean ± SD (all such values)
3
At the time of the study, this amount was roughly equal to US$0.75/d.
4
From a list that included a sofa, television, radio, refrigerator, and fan.
5
n = 2157
6
Calculated on the basis of the standards developed by Oken et al. (23).
7
Anthropometric z scores from baseline (ages 5–7 wk).