Table 1.
Studies investigating Vitamin D supplementation for children.
| References (Authors, Year, Country) | Patients, n | Intervention (VD Prophylaxis) | Timing of the Study (Since Delivery) | Main Outcome | Adverse Events |
|---|---|---|---|---|---|
| Alonso et al. 2011, Spain [30] | 88 (n = 41 intervention group, n = 47 placebo group) | 400 IU/d; oral | From 1 to 12 months | 25(OH)D levels significantly >35 ng/mL at 3 and 6 months in the intervention group only | None |
| Holmlund-Suila et al. 2012, Finland [31] | 93 (n = 29 group 1, n = 32 group 2, n = 32 group 3) | 400 IU/d (group 1), 1200 IU/d (group 2), 1600 IU/d (group 3); oral | From 2 weeks to 3 months | Final serum 25(OH)D concentration >20 ng/mL in all children (regardless of VD dosing) | None |
| Gallo et al. 2013, Canada [32] | 132 (n = 39 group 1, n = 39 group 2, n = 38 group 3, n = 16 group 4) | 400 IU/d (group 1), 800 IU/d (group 2), 1200 IU/d (group 3), 1600 IU/d (group 4); oral | From 1 to 12 months | All dosages established 25(OH)D concentrations of >20 ng/mL or above in 97% of infants at 3 months and maintained this in 98% of infants for 12 months | None |
| Ziegler et al. 2014, USA [33] | 142 (n = 43 group 1, n = 37 group 2, n = 36 group 3, n = 26 group 4) | 200 IU/d (group 1), 400 IU/d (group 2), 600 IU/d (group 3), 800 IU/d (group 4); oral | From 1 to 10 months | Most infants had low (<25 ng/mL) 25(OH)D levels at 1 month, although levels increased with supplementation; the highest doses were more efficacious in maintaining VD sufficiency, although the findings support the recommended 400 IU/d dose. | None |
| Moodley et al. 2015, Mexico [34] | 49 (n = 27 intervention group, n = 22 placebo group) | Single dose of 50,000 IU; oral | From 24 h after birth to 6 months | Sustained levels of VD >32 ng/mL through the first 6 months in the intervention group | None |
| Huynh et al. 2017, Australia [35] | 70 (n = 36 group 1, n = 34 group 2) | 400 IU/d (group 1) vs. single 50,000 IU dose (group 2); oral | From 0 to 4 months | Higher 25(OH)D sufficiency rates (>20 ng/mL) at 1–2 weeks in group 2 compared with group 1; similar rates by 3–4 months | None |
| Houghton et al. 2011, New Zealand [36] | 181 (n = 107 intervention group, n = 74 control—meat derived food) | VD fortified milk (40 IU/100 mL) | From 12 to 20 months | Significantly lower prevalence of 25(OH)D level <20 ng/mL (insufficiency) in the intervention group | Not available |
| Akkermans et al. 2017, Germany/ Netherlands/ England [37] | 318 (n = 158 intervention group, n = 160 control—cow’s milk) | VD fortified milk (70 IU/100 mL) | Children aged 12–36 months for 20 weeks | Decreased VD deficiency rate in the intervention group and increased rate in the control group (−11.8% vs. +11.4%); mean 25(OH)D level in the intervention group >30 ng/mL | No differences in the number or severity between the two groups |