Summary of meta-analysis findings by outcome
| Outcome . | Iron + vitamin C (incidence/sample size) . | Iron with no vitamin C (incidence/sample size) . | Effect size . | No. of studies in systematic review (total sample size N = 1930) . |
|---|---|---|---|---|
| Primary outcome | ||||
| Change in serum Hb levels (g/dL) | NA/sample size | NA/sample size | MD, 0.14 (95% CI, 0.08-0.20; P < .01; I2 = 86%) | 10 (n = 1490) |
| Secondary outcomes | ||||
| Change in serum ferritin levels (μg/L) | NA/sample size | NA/sample size | MD, 3.23 (95% CI, 1.63-4.84; P < .01; I2 = 95%) | 9 (n = 1682) |
| Change in reticulocyte percentage (%) | NA/sample size | NA/sample size | MD, 0.22 (95% CI, 0.08-0.36; P <.01; I2 = 94%) | 3 (n = 620) |
| Adverse events outcomes | ||||
| Incidence of all adverse events (events/total sample) | 76/680 | 113/820 | OR, 0.71 (95% CI, 0.50-1.00; P = .05; I2 = 0%) | 3 (n = 1500) |
| Incidence of constipation (events/total sample) | 19/300 | 30/320 | OR, 0.83 (95% CI, 0.35-1.96; P = .66; I2 = 0%) | 3 (n = 620) |
| Incidence of nausea or vomiting (events/total sample) | 45/300 | 58/360 | OR, 0.80 (95% CI, 0.52-1.24; P = .32; I2 = 40%) | 3 (n = 660) |
| Incidence of GI irritation (events/total sample) | 12/80 | 25/140 | OR, 0.40 (95% CI, 0.18-0.92; P = .03; I2 = 0%) | 2 (n = 220) |
| Incidence of poor taste (events/total sample) | N/A | N/A | Not estimable | 0 |
| Outcome . | Iron + vitamin C (incidence/sample size) . | Iron with no vitamin C (incidence/sample size) . | Effect size . | No. of studies in systematic review (total sample size N = 1930) . |
|---|---|---|---|---|
| Primary outcome | ||||
| Change in serum Hb levels (g/dL) | NA/sample size | NA/sample size | MD, 0.14 (95% CI, 0.08-0.20; P < .01; I2 = 86%) | 10 (n = 1490) |
| Secondary outcomes | ||||
| Change in serum ferritin levels (μg/L) | NA/sample size | NA/sample size | MD, 3.23 (95% CI, 1.63-4.84; P < .01; I2 = 95%) | 9 (n = 1682) |
| Change in reticulocyte percentage (%) | NA/sample size | NA/sample size | MD, 0.22 (95% CI, 0.08-0.36; P <.01; I2 = 94%) | 3 (n = 620) |
| Adverse events outcomes | ||||
| Incidence of all adverse events (events/total sample) | 76/680 | 113/820 | OR, 0.71 (95% CI, 0.50-1.00; P = .05; I2 = 0%) | 3 (n = 1500) |
| Incidence of constipation (events/total sample) | 19/300 | 30/320 | OR, 0.83 (95% CI, 0.35-1.96; P = .66; I2 = 0%) | 3 (n = 620) |
| Incidence of nausea or vomiting (events/total sample) | 45/300 | 58/360 | OR, 0.80 (95% CI, 0.52-1.24; P = .32; I2 = 40%) | 3 (n = 660) |
| Incidence of GI irritation (events/total sample) | 12/80 | 25/140 | OR, 0.40 (95% CI, 0.18-0.92; P = .03; I2 = 0%) | 2 (n = 220) |
| Incidence of poor taste (events/total sample) | N/A | N/A | Not estimable | 0 |
N/A, not applicable.