Table 1.

The summary of the patient, intervention/exposure, comparator, outcome, and study design (PICOS) criteria for inclusion and exclusion of studies in a systematic review.

PICOS Parameter	Inclusion Criteria	Exclusion Criteria
Population	Multiple sclerosis adult patients	Children and adolescents with multiple sclerosis, individuals with any intellectual disabilities, any eating disorders, or any other neurological disorders
Intervention/exposure	Any vitamin D supplementation applied	Vitamin D applied within multiple nutrients supplementation
Comparison	Influence on a mental health outcomes assessed while compared with baseline/placebo/various doses and regimens	Lack of comparison
Outcome	Any mental health outcome assessed	Cognitive function assessed
Study design	Articles published in peer-reviewed journals, in English	Articles not published in English, reviews, meta-analyses, expert opinions, letters to editor, comments, studies in animal models, methodological articles, case reports, conference reports