Table 2.

General characteristics of the selected studies.

Athletic level of participants	Young men/High school	2 studies: Pilch et al., 2020 [36]    Shanely et al., 2014 [33]
	Resistance-trained men/Male runners	2 studies: Ashtary-Larky et al., 2020 [35]    Żebrowska et al., 2020 [37]
	Male soccer players	1 study: Parsaie et al., 2019 [34]
	NASCAR pit crew	1 study: Nieman et al., 2013 [32]
Age of participants	<20 years old	1 study: Shanely et al., 2014 [33]
	20–30 years old	4 studies: Nieman et al., 2013 [32]    Parsaie et al., 2019 [34]    Ashtary-Larky et al., 2020 [35]    Pilch et al., 2020 [36]
	30–40 years old	1 study: Żebrowska et al., 2020 [37]
Vitamin D administration	Ingestion	5 studies: Nieman et al., 2013 [32]    Parsaie et al., 2019 [34]    Pilch et al., 2020 [36]    Shanely et al., 2014 [33]    Żebrowska et al., 2020 [37]
	Injection	1 study: Ashtary-Larky et al., 2020 [35]
Vitamin D dose (type)	600 IU/day (vitD2)	1 study: Shanely et al., 2014 [33]
	2000 IU/week (vitD3)	1 study: Żebrowska et al., 2020 [37]
	3800 IU/day (vitD2)	1 study: Nieman et al., 2013 [32]
	50,000 IU/day (vitD3)	1 study: Parsaie et al., 2019 [34]
	300,000 IU injected in one dose (vitD3)	1 study: Ashtary-Larky et al., 2020 [35]
	Calculated from participant’s body mass using Singh and Bonham formula (vitD3)	1 study: Pilch et al., 2020 [36]
Extent of supplementation	3 weeks	1 study: Żebrowska et al., 2020 [37]
	4 weeks	1 study: Ashtary-Larky et al., 2020 [35]
	6 weeks	2 studies: Nieman et al., 2013 [32]    Shanely et al., 2014 [33]
	8 weeks	1 study: Parsaie et al., 2019 [34]
	12 weeks	1 study: Pilch et al., 2020 [36]
Exercise type	Eccentric exercise	3 studies: Nieman et al., 2013 [32]    Pilch et al., 2020 [36]    Żebrowska et al., 2020 [37]
	Loughborough intermittent shuttle test	2 studies: Parsaie et al., 2019 [34]    Shanely et al., 2014 [33]
	Acute resistance exercise (different presses and weights)	1 study: Ashtary-Larky et al., 2020 [35]

Abbreviations used: IU, international units; VitD₂, ergocalciferol; VitD₃, cholecalciferol.