Effect of the COVID-19 Pandemic on Serum Vitamin D Levels in People Under Age 18 Years: A Systematic Review and Meta-Analysis

25 May 2022: Meta-Analysis

Xian Cui ^1ABCDEF** , Yuhang Zhai ^2CE* , Shuai Wang ^1BF , Ke Ding ^1E , Zhenya Yang ^1E , Yan Tian ^1D , Tingting Huo ^1D

DOI: 10.12659/MSM.935823

Med Sci Monit 2022; 28:e935823

Supplementary Table 1 Quality assessment of included studies by Newcastle-Ottawa Scale.

NOS case-control Study	Is the case definition adequate?	Representativeness of the cases	Selection of controls	Definition of controls	Comparability of cases and controls on the basis of the design or analysis	Ascertainment of intervention	Same method of ascertainment for cases and controls	Non-response rate	Total quality scores
Kang et al, 2020	✰	✰	✰	✰	✰✰	–	✰	✰	8
Feketea et al, 2021	✰	✰	✰	✰	✰	–	✰	✰	7
Wong et al, 2021	✰	✰	✰	✰	✰	–	✰	✰	7
Rustecka et al, 2021	✰	✰	–	✰	✰	–	✰	✰	6
Yu et al, 2020	✰	✰	–	✰	✰	–	✰	✰	6