Sharifi 2014.

Methods	Randomised clinical trial with parallel group design (2 groups).
Participants	60 (51% women), aged 18 to 70 years, mean age 42 years, with NAFLD. Inclusion criteria: diagnosis of NAFLD by US and increased serum levels of ALT (> 19 U/L for women and 30 U/L for men). Exclusion criteria: alcohol consumption > 20 g/day; pregnant and lactating women; hereditary haemochromatosis; Wilson's disease; α1‐antitrypsin deficiency; history of jejunoileal bypass surgery or gastroplasty; using total parenteral nutrition in the past 6 months; taking hepatotoxic drugs such as calcium channel blocker, high doses of synthetic oestrogens, methotrexate, amiodarone, and chloroquine; history of hypothyroidism, Cushing's syndrome, renal failure, and kidney stones; serum calcium levels > 10.6 mg/dL; and intake of vitamin D, vitamin E, and calcium supplements during the last 6 months.
Interventions	Intervention: vitamin D3 50,000 IU (D‐Vitin Zahravi Pharm Co., Tabriz, Iran) (n = 30). Control: placebo (Zahravi Pharm Co.) (n = 30). Every 14 days for 4 months.
Outcomes	Primary outcomes: changes in serum ALT and changes in insulin resistance index. Secondary outcomes: other liver enzymes, oxidative stress, and inflammatory biomarkers.
Stated aim of study	To determine effect of vitamin D supplementation on serum liver enzymes, insulin resistance, oxidative stress, and inflammatory biomarkers in people with NAFLD.
Notes	Study financially supported by grant (No. RDC‐9105) from Vice‐Chancellor for Research Affairs of Jundishapur University of Medical Sciences and approved by the Research Institute for Infectious Diseases of the Digestive System, Jundishapur University of Medical Sciences, Ahvaz, Iran.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	The study authors performed sequence generation using computer random number generation
Allocation concealment (selection bias)	Low risk	An investigator with no clinical involvement in the trial packed the supplements and placebos in numbered bottles based on the random list. The other person, who was not involved in the trial and not aware of random sequences, assigned the patients to the numbered bottles of pearls.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Blinding of participants and key study personnel ensured, and it was unlikely that the blinding could have been broken.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Blinding of outcome assessment ensured, and unlikely that the blinding could have been broken.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Missing data were unlikely to make treatment effects depart from plausible values.
Selective reporting (reporting bias)	Unclear risk	It is unclear whether all predefined and clinically relevant and reasonably expected outcomes were reported.
For‐profit bias	Low risk	The trial appeared to be free of industry sponsorship or other type of for‐profit support that could manipulate the trial design, conductance, or trial results.
Other bias	Low risk	The trial appeared to be free of other factors that could put it at risk of bias.