Table 6.

The detailed characteristics of the applied vitamin D supplementation intervention and mental health outcomes for the studies of the irritable bowel syndrome (IBS) patients included to the systematic review.

Ref.	Vitamin D Measure	Intervention—Vitamin D Supplementation	Mental Health Outcome	Psychological Measure
[36]	25(OH)D vitamin D level in blood FFQ	75 µg/day vs. placebo for 12 weeks	Quality of life	Simple question (“How much has IBS affected your life?”)
[37]	25(OH)D vitamin D level in blood	1250 µg/2 weeks vs. placebo for 6 months	Disease-specific quality of life	IBS-QoL
[38]	Three 24-h dietary recalls	1250 µg/2 weeks vs. placebo for 6 weeks	Disease-specific quality of life	IBS-QoL
[39]	25(OH)D vitamin D level in blood 3-days dietary recall	1250 µg/week vs. placebo for 6 weeks	Disease-specific quality of life	IBS-QoL
[40]	25(OH) vitamin D level in blood 3-day dietary records	1250 µg/week vs. placebo for 9 weeks	(1) Disease-specific quality of life (2) Anxiety and depression	(1) IBS-QoL (2) HADS
[41]	25(OH) vitamin D level in blood	75 µg/day vs. placebo for 12 weeks	Disease-specific quality of life	IBS-QoL

25-hydroxyvitamin D (25(OH)D); FFQ—Food Frequency Questionnaire; IBS-QoL—Irritable Bowel Disease-Quality of Life questionnaire; HADS—Hospital Anxiety and Depression Scale.