Table I.

Modified and updated table previously published by Thompson et al. (21), including studies that examined serum zinc (Zn) levels in patients with alopecia areata (AA)

Study	Year	Study type	Study population	Sample size	Results
Abdel Fattah et al. (12)	2016	Case-control (hospital-based)	Sex: 39M/11F; Age: 27 ± 9.5 years Country: Egypt	100 (50 AA cases and 50 sex- and age-matched controls)	Significantly lower serum Zn in AA patients vs controls
Bhat et al. (13)	2009	Case-control (hospital-based)	Sex: 34M/16F; Age: 27.3 years Country: India	100 (50 AA cases and 50 healthy sex- and age- matched controls	Significantly lower serum Zn in AA patients vs controls
Mussalo-Rauhamaa et al. (14)	1986	Case-control (hospital-based)	Sex: 8M/19F; Age: 29 ± 11 years Country: Finland	27 AA cases compared with normal Finnish population reference values	No difference in serum zinc levels in AA vs normal population. Compared AA cases to serum zinc values from the normal Finnish population
Dastgheib et al. (15)	2014	Case-control (not described)	Sex: 16F; Age: 26.6 ± 8.5 years Country: Iran	43 (16 AA cases and 27 sex- and age-matched healthy controls)	No difference in serum zinc levels or hair zinc levels in AA patients vs controls
Amirnia et al. (16)	2013	Case-control (hospital-based)	Sex: 3M/24F; Age: 66.3 ± 9.9 years Country: Iran	54 (27 AA cases and 27 healthy sex- and age- matched controls)	Significantly lower serum and hair Zn in AA patients vs controls
Kil et al. (7)	2013	Case-control (hospital-based)	Sex: 44M/50F; Age: 37.1 ± 14.9 years Country: Korea	126 (94 AA cases and 32 healthy controls)	Significantly lower serum Zn in AA patients vs controls
Current study	2023	Case-control (hospital-based)	Sex: 13M/19F; Age: 18.1 ± 13.4 years, Children/Adults: 20/12 Country: Serbia	64 (32 AA cases and 32 healthy sex- and age-matched controls)	Significantly lower serum Zn in AA patients vs controls