Table 1 Basic characteristics of included studies
Study | Country | Group | Sample size | Age (years) | BMI (kg/m²) | Intervention | Duration (weeks) | Outcome measures |
|---|---|---|---|---|---|---|---|---|
Al-Bayyari 2021 [9] | Jordan | Vitamin D group | 29 | 23.6 ± 4.3 | 27.3 ± 1.9 | 50,000 IU/week of vitamin D3 | 12 | ①② |
Placebo group | 29 | 23.9 ± 6.0 | 26.9 ± 1.6 | Placebo | 12 | |||
Ardabili 2012 [10] | Iran | Vitamin D group | 24 | 26.8 ± 4.7 | 29.1 ± 4.6 | 5,000 IU/daily of vitamin D3 | 8 | ①② |
Placebo group | 26 | 27.0 ± 3.7 | 28.3 ± 3.5 | Placebo | 8 | |||
Asemi 2015 [11] | Iran | Vitamin D group | 26 | 25.6 ± 4.4 | 29.3 ± 3.9 | 50,000 IU/week of vitamin D3 | 8 | ①②③④⑤⑥⑦ |
Placebo group | 26 | 24.3 ± 5.2 | 27.5 ± 5.2 | Placebo | 8 | |||
Dastorani 2018 [12] | Iran | Vitamin D group | 20 | 29.9 ± 4.4 | 27.7 ± 3.9 | 50,000 IU/week of vitamin D3 | 8 | ①②③④⑤⑥⑦ |
Placebo group | 20 | 30.1 ± 3.4 | 28.4 ± 2.6 | Placebo | 8 | |||
Foroozanfard 2017 [13] | Iran | Vitamin D group | 30 | 18 ~ 40 | Na | 4,000 IU/day of vitamin D3 | 12 | ①②③④⑤⑥⑦ |
Placebo group | 30 | 18 ~ 40 | Na | Placebo | 12 | |||
Garg 2015 [14] | India | Vitamin D group | 15 | 22.0 ± 4.6 | 26.8 ± 4.6 | 4,000 IU/day of vitamin D3 | 24 | ①③④⑤⑥⑦ |
Placebo group | 17 | 22.8 ± 4.6 | 26.7 ± 6.1 | Placebo | 24 | |||
Irani 2015 [15] | USA | Vitamin D group | 35 | 30.5 ± 1.0 | 30.0 ± 1.0 | 50,000 IU/week of vitamin D3 | 8 | ②③④⑥⑦ |
Placebo group | 18 | 29.6 ± 1.7 | 28.0 ± 1.6 | Placebo | 8 | |||
Javed 2019 [16] | United Kingdom | Vitamin D group | 18 | 28.6 ± 5.5 | 35.4 ± 10.6 | 3,200 IU/day of vitamin D3 | 12 | ①②③④⑥⑦ |
Placebo group | 19 | 29.1 ± 7.5 | 33.8 ± 7.2 | Placebo | 12 | |||
Maktabi 2017 [17] | Iran | Vitamin D group | 35 | 22.0 ± 1.6 | 22.7 ± 3.4 | 50,000 IU/2 weeks of vitamin D3 | 12 | ①③④⑥⑦ |
Placebo group | 35 | 23.1 ± 3.3 | 24.1 ± 3.8 | Placebo | 12 | |||
Rahimi-Ardabili 2013 [18] | Iran | Vitamin D group | 24 | 26.8 ± 4.7 | 29.1 ± 4.6 | 50,000 IU/2 weeks of vitamin D3 | 12 | ②③④⑥⑦ |
Placebo group | 26 | 27.0 ± 3.7 | 28.3 ± 3.5 | Placebo | 12 | |||
Raja-Khan 2014 [19] | USA | Vitamin D group | 13 | 28.2 ± 5.2 | 37.2 ± 4.5 | 12,000 IU/day of vitamin D3 | 12 | ①②③④⑤⑥⑦ |
Placebo group | 15 | 28.7 ± 5.6 | 35.1 ± 9.8 | Placebo | 12 | |||
Seyyed Abootorabi 2018 [20] | Iran | Vitamin D group | 21 | 26.2 ± 4.6 | Na | 50,000 IU/week of vitamin D3 | 8 | ①② |
Placebo group | 17 | 22.7 ± 4.4 | Na | Placebo | 8 | |||
Trummer 2019 [21] | Austria | Vitamin D group | 81 | 25.4 ± 4.6 | 27.3 ± 7.4 | 20,000 IU/week of vitamin D3 | 24 | ①|
Placebo group | 42 | 27.2 ± 5.5 | 28.3 ± 7.8 | Placebo | 24 |