Krikorian 2010.

Methods	2‐arm, placebo‐controlled, randomised, controlled trial, duration 12 weeks
Participants	Location: Cincinnati, Ohio, USA. Single centre. Setting of recruitment and treatment: Recruitment via advertisement for volunteers with mild memory problems. Study conducted at Department of Psychiatry and Neuroscience, University of Cincinnati College of Medicine. Sample size: Number randomised: 15 in intervention, 11 in comparison. Number completed: 15 in intervention, 11 in comparison. Participant (Baseline) characteristics: Age in years (mean ± SD): CrPic: 72.2 ± 7.0, placebo 69.8 ± 4.7 Inclusion criteria: Elderly individuals with CDR (Clinical Dementia Rating scale) classification of 0.5, indicating early memory decline consistent with MCI. Exclusion criteria: Diabetes; Liver or kidney disease; Substance abuse disorder; Diagnosed with a psychiatric or neurological condition.
Interventions	Active intervention: Chromium picolinate (CrPic) containing 1000 mcg elemental chromium once daily for 12 weeks. Comparator: Placebo once daily.
Outcomes	Outcomes of interest in the review: Specific cognitive functioning subdomain: episodic memory: California Verbal Learning Test (CVLT)
Source of Funding	Funding and material support for this research was provided by Nutrition 21, Inc., Purchase, NY, USA.
Declaration of Interest	No declarations provided.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "Enrolled subjects were randomly assigned in a double‐blind manner to receive chromium picolinate (CrPic), containing 1000 mcg elemental chromium, or placebo for 12 weeks". Comment: Insufficient information about sequence generation.
Allocation concealment (selection bias)	Unclear risk	Comment: Method of allocation concealment not described in the paper.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote: "double‐blind". Comment: Insufficient information regarding the blinding of participants and personnel.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quote: "double‐blind" Comment: Insufficient information in the paper for judgement on the level of risk.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Comment: The paper did not mention any participants lost to follow‐up or missing data.
Selective reporting (reporting bias)	Low risk	No protocol available. All outcomes mentioned in Methods section reported.
Other bias	Low risk	No other risks identified.