Table 3. Mean changes in serum vitamin D concentration during supplementation with vitamin D in the intervention and control groups in selected studies.
| Study | Supplemented dose of vitamin D (IU/d) | Analysed groups | Serum 25(OH)D (nmol/l) concentration Mean ± SD |
|
|---|---|---|---|---|
| Baseline | Intervention | |||
| Salehpour A. et al.25 | 1000 | D groupb Control group | 36.80 ± 30.00 46.90 ± 32.00 | 75.00 ± 22.00 51.50 ± 31.00 |
| Mason C. et al.21 | 2000 | D groupb Control group | 53.40 ± 15.50 53.40 ± 15.20 | 87.40 ± 23.50 50.20 ± 16.70 |
| Beilfuss J. et al.27 | 2857/5714c,d | D groupb Control group | 54.30 (15.40–111.50)a 52.40 (18.50–99.40)a | 99.00 (46.70–193.40)a 50.00 (20.30–99.80)a |
| Zittermann A. et al.31 | 3332 | D groupb Control group | 30.0 ± 17.5 30.3 ± 20.1 | 85.5 ± 57.5 42.0 ± 35.0 |
| Kelishadi R. et al.20 | 3571c | D groupb Control group | 45.60 ± 5.09 44.70 ± 5.66 | 79.89 ± 5.34 47.59 ± 5.02 |
| Belenchia A. M. et al.22 | 4000 | D groupb Control group | 47.90 ± 15.70 48.90 ± 19.70 | 99.80 54.90 |
| Carrillo A. E. et al.24 | 4000d | D groupb Control group | 51.90 ± 20.70 45.20 ± 16.20 | 83.40 ± 18.00 58.70 ± 15.00 |
| Harris S. S. et al.28 | 4000d | D groupb Control group | 39.60 ± 12.90 38.20 ± 15.50 | 81.10 ± 27.90 37.40 ± 16.10 |
| Wamberg L. et al.22 | 7000 | D groupb Control group | 33.0 ± 10.8 34.0 ± 9.0 | 110.2 ± 21.2 46.8 ± 17.3 |
| Nagpal J. et al.30 | 12000 | D groupb Control group | 35.1 ± 27.28e 0.65 ± 11.78 | |
*The changes in the serum 25(OH)D concentration between baseline and the end of intervention were statistically significant (p < 0.05) in the D groups of each analysed study.
aMean and range.
bGroup receiving vitamin D supplementation.
cVitamin D was administered once a week.
dAdditional calcium supplementation (500–600 mg/d).
eChanges where p < 0.0001.