Table 6 GRADE evidence profile for VitD food fortification for preventing vitD deficiency among children
Certainty assessment | Summary of findings | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
No. of participants (studies)Follow-up | Risk of bias | Inconsistency | Indirectness | Imprecision | Other considerations | Overall certainty of evidence | Number of children | Relative effect (95% CI) | Anticipated absolute effects | ||
No. fortification | Vitamin D fortification | Risk with no fortification | Risk difference with vitamin D fortification | ||||||||
25(OH)D concentration (follow-up: range 2 to 24 months; assessed with: nmol/L) | |||||||||||
4044 (18 RCTS) | Not serious | Seriousa, b | Not serious | Not serious | Strong associationd | ⨁⨁⨁⨁High | 1731 | 2313 | – | The mean vitamin D concentration was 44 nmol/L | MD 15.51 nmol/L higher (6.28 higher to 24.74 higher) |
Vitamin D deficiency prevalence (follow up: range 2 to 24 months) | |||||||||||
4093 (16 RCTS) | Not serious | Seriousa | Not serious | Not serious | Strong associationd | ⨁⨁⨁⨁High | 739/1732 (42.7%)* | 632/2361 (26.8%)* | RR 0.53 (0.41 to 0.69) | 427 per 1000 | 201 fewer per 1000 (252 to 132 fewer) |
Cognitive function (follow up: range 6 to 14 months; assessed with: IQ) | |||||||||||
904 (2 RCTS) | Seriousc | Not serious | Not serious | Not serious | Strong associatione | ⨁⨁⨁OModerate | 446 | 458 | – | - | MD 1.22 IQ points higher (0.65 higher to 1.79 higher) |
School grade for Math (follow up: range 6 to 14 months) | |||||||||||
904 (2 RCTs) | Seriousc | Seriousa | Not serious | Serious | None | ⨁OOOVery LOW | 446 | 458 | – | – | SMD 0.90 SD higher (0.39 lower to 2.18 higher) |