Association of self-reported symptoms with serum levels of vitamin D and multivariate cytokine profile in healthy women

Abstract

Background: Although a large number of studies have investigated possible relationships among serum levels of vitamin D or cytokines with disease progress and prognosis, similar studies on self-reported symptoms are still controversial. The overall objective of this study was to look into the association between serum levels of vitamin D or cytokines with self-reported symptoms related to musculoskeletal pain, sleep disorders, and premenstrual syndrome (PMS) in healthy adult women.

Subjects and methods: Venous blood samples were collected from 117 healthy adult women, and serum levels of vitamin D, pro-inflammatory cytokines (IL-1β, IL-6, IL-8, IL-17, IFN-γ, and TNF-α) and anti-inflammatory cytokines (IL-4, IL-10, and IL-13) were measured. Groups were tested for differences in single parameters, pro-:anti-inflammatory cytokine ratios, and differences in multivariate patterns.

Results: There were no significant associations between serum levels of vitamin D and any of the self-reported symptoms studied. However, serum levels of certain pro-inflammatory cytokines were significantly higher in subjects with musculoskeletal pain (IL-8, P=0.008), sleep disorders (IFN-γ, P=0.02), and PMS (IL-8 and TNF-α, P=0.009 and 0.002, respectively) compared to subjects who reported no symptoms. The pro-:anti-inflammatory cytokine ratios showed pro-inflammatory cytokine dominance in subjects with self-reported symptoms, particularly in the groups with deficient levels of vitamin D. However, the multivariate cytokine-pattern analysis was significantly different between PMS groups only.

Conclusion: These data point to a possible role of pro-inflammatory cytokines as a contributing factor in self-reported symptoms related to musculoskeletal pain, sleep disorders, and PMS.

Keywords: adult women; cytokines; inflammation; self-reported symptoms; vitamin D.

Figure 1

Median serum levels of (A) IL-8, (B) IL-17, (C) IFN-γ, and (D) TNF-α in the subject groups. Abbreviations: S, symptomatic; NS, not symptomatic; D, deficient levels of vitamin D, ND, non-deficient levels of vitamin D.