Hosseini 2018.

Study characteristics
Methods	Randomised clinical trial with parallel‐group design (2 groups)
Participants	Country: Iran Number of participants randomised: 82 women, aged 18 to 50 years, mean age 34 years Inclusion criteria: BMI between 25 and 40 kg/m2 with NAFLD confirmed by single ultrasonographist, vitamin D insufficiency (serum 25‐hydroxyvitamin D < 30 ng/mL), not taking dietary supplements including calcium and vitamin D over the last 6 months Exclusion criteria: renal, hepatic, other endocrine disorders, malignancies, pregnancy and lactation, alcohol consumption, menopause condition, receiving medications influencing vitamin D metabolism or insulin
Interventions	Intervention: vitamin D3 (cholecalciferol) 600,000 IU single intramuscular injection (n = 41) Control: no intervention (n = 41) All participants received pearl of vitamin E 400 IU/day for 1 month. Participants were followed up for 1 month.
Outcomes	Primary outcomes: changes in serum 25‐hydroxyvitamin D, serum adiponectin, HOMA‐IR, liver enzymes, and change in grade of NAFLD Secondary outcomes: change in anthropometric variables
Stated aim of study	To examine the effect of single intramuscular injection of 600,000 IU of cholecalciferol on serum levels of vitamin D, adiponectin, insulin resistance, and liver function status of women with NAFLD
Notes	Study authors did not report any deaths. No information provided about adverse events.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "The patients were randomly assigned in the random blocks of four subjects using a computer Random Allocation Software, version 1, with stratification by age."
Allocation concealment (selection bias)	Unclear risk	Method used to conceal the allocation not described, so intervention allocations may have been foreseen before, or during, enrolment.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Insufficient information to permit judgement of 'low risk' or 'high risk'
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Insufficient information to permit judgement of 'low risk' or 'high risk'
Incomplete outcome data (attrition bias) All outcomes	Low risk	Missing data unlikely to make treatment effects depart from plausible values.
Selective reporting (reporting bias)	Low risk	The trial was registered in the Iranian Registry of Clinical Trials with code number of IRCT201503163320N10.
Other bias	Low risk	Trial appeared to be free of other factors that could put it at risk of bias.