Table 2.
Study design, participants, and details of RCTs assessing 400 IU/day vitamin D supplementation in 1–12-month-old infants.
| First Author | Dose (IU) | Comparison (IU) | Intervention Duration (months old) | Blinding | Sample Size of 400 IU Group | Country | |
|---|---|---|---|---|---|---|---|
| Randomisation | Analysis | ||||||
| Rueter, K. [47] | 400 | placebo | 1–6 | double | 98 | 86 * | Australia (35°S) |
| Alonso, A. [48] | 400 | no treatment | 1–12 | none | 41 | 30 | Spain (43°N) |
| Ziegler, E.E. [49] | 400 | 200,600,800 | 1–9 | double | 60 | 30 | USA (41°N) |
| Gallo, S. [50] | 400 | 800,1200,1600 | 1–12 | double | 39 | 29 | Canada (45°N) |
* this number includes infants who discontinued the intervention, and it is unclear if it includes infants who attended the 6-month endpoint but did not have their 25(OH)D measured. IU = international units.