2.3. | Data extraction
Study selection and data extraction was performed by two independent researchers (FM and MRA). Any disagreements about eligibility were discussed with a third reviewer (SS-b). Data abstracted from the eligible studies were (a) first author’s name; (b) year of publication; (c) study design; (d) intervention (type, dose and duration of supplementation); (e) number of participants; (g) subjects’ information, age, sex, and health status; and (h) outcomes (ALT, AST) assessed, before and after the intervention of serum ALT, AST.