Table 5.

The observations and conclusion formulated within the studies of multiple sclerosis (MS) patients included to the systematic review.

Ref.	Observations	Conclusions
[35]	After 3 months, the vitamin D group had a significant difference in mental health component of quality of life with placebo group, 62.41 ± 13.99 vs. 60.99 ± 17.99 (p = 0.041). Change in health component of quality of life was 75.74 ± 25.73 and 70.59 ± 26.45 in vitamin D and placebo group, respectively (p = 0.036).	Mental quality of life improved significantly after taking high dose vitamin D for 3 months in vitamin D group relative to placebo. Also a positive change in health status was reported by patients receiving high dose vitamin D relative to placebo group.
[36]	Pre- and post-supplementation depression scores, measured using the Hospital Anxiety Depression Scale (HADS) depression subscale (HADS-D), showed a significant decrease within the vitamin D3 group (median HADS-D 4.0 to 3.0, p = 0.02), a trend towards a decrease within the placebo group (median HADS-D 3.0 to 2.0, p = 0.06), but no significantly different reductions between groups (p = 0.78).	There was no evidence for a reduction of depressive symptoms upon vitamin D3 supplementation in relapsing remitting multiple sclerosis patients.
[37]	Depressive symptoms were high at baseline and improved with vitamin D replacement although, Expanded Disability Status Scale (EDSS) score was not improving. Vitamin D levels correlated negatively with depressive symptoms at baseline and follow up periods.	Lower vitamin D levels are associated with higher depressive scores, and vitamin D replacement could improve depressive symptoms in patients with relapsing remitting multiple sclerosis.
[38]	After vitamin D supplementation, health-related quality of life and fatigue scores improved significantly. There was a direct association between health-related quality of life with absence of fatigue and vitamin D status at the end of study.	The 90% frequency of multiple sclerosis patients with vitamin D deficiency, together with the significant association of vitamin D status with the absence of fatigue and improved physical and functional well-being, points to vitamin D supplementation as a potential therapy to enhance the patient’s quality of life.
[39]	Vitamin D supplementation at baseline was associated with lower frequency of positive depression-screen 2.5 years later. After adjusting for potential confounders, vitamin D supplementation was not associated with a change in risk for depression.	Vitamin D supplementation was associated with lower frequencies of depression risk, but this association was no longer significant after adjusting for potential confounders.
[40]	At 2.5-year follow-up, quality of life scores were higher among participants reporting taking vitamin D supplements (physical: aβ = 3.58, 95% CI = 1.35–5.80; mental: aβ = 3.08, 95% CI = 0.72–5.44), particularly average daily dose over 125 µg/d. Baseline-reported vitamin D supplementation was associated with greater increase in physical (aβ = 1.02, 95% CI = 0.22–1.81), but not mental quality of life (aβ = 0.11, 95% CI = −1.00–1.23).	Self-reported vitamin D supplement use was cross-sectionally associated with higher physical and mental quality of life, but prospectively only with increased physical quality of life.

CI—confidence interval.