Bjorneboe 1989.

Methods	This was a randomised controlled trial (single centre, Norway). D = parallel AC =unclear RS = block randomisation B = unclear
Participants	Inclusion criteria of the trial 31 adults aged 16 to 56 years. 23 were evaluable (7 men and 16 women) Setting = unclear SAE = unclear Dig = Hanifin and Rajka Co‐T = allowed to use topical steroid
Interventions	T1: fish oil (18% eicosapentaenoic acid (EPA), 12% docosahexaenoic acid (DHA), 30% total n‐3 fatty acids, and 3% total n‐6 fatty acids). Each capsule contained 1 IU alpha‐tocopherol as antioxidant, 100 IU vitamin A, and 10 IU vitamin D (n = 16) T2: olive oil placebo (n = 15) T1 vs T2 ‐ 10 capsules daily for 12 weeks
Outcomes	1) The objective evaluation of erythema, scale, visibility, severity, excoriation, weeping, lichenification, and area affected were separately assessed in a 10‐point score system 2) Participants, in addition, noted the degree of erythema, visibility, itch, scale, and effect on daily living in a similar score system Each final symptom score (after 12 weeks of intervention) in the objective and subjective evaluation was subtracted from the initial symptom score for each participant.
Notes	A per‐protocol analysis was undertaken. There were no randomisation details. The baseline characteristics (age and sex, severity and intensity of AD) were only described for those completing supplementation. There were 4 dropouts in each group due to inability to swallow capsules. No ITT was carried out.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No details were given.
Allocation concealment (selection bias)	Unclear risk	No details were given.
Blinding (performance bias and detection bias) All outcomes	Unclear risk	The blinding was not clear (double‐blind was stated in the Methods).
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	There were 4 dropouts in each group due to inability to swallow capsules. No ITT was carried out.
Certainty of AD	Low risk	This was measured using criteria by Hanifin and Rajka.
Baseline comparability	Unclear risk	Baseline characteristics (age and sex, severity and intensity of AD) were described only for those completing supplementation.
Compliance	Low risk	This was evaluated by measuring the fatty acid composition of serum phospholipids at baseline and at the end of the study by gas chromatography.
Severity of AD	Unclear risk	This was not stated.
Conflict of interest	Low risk	This was a university study.