Vitamin D status is independently associated with plasma glutathione and cysteine thiol/disulphide redox status in adults

Abstract

Summary Objective Redox status and inflammation are important in the pathophysiology of numerous chronic diseases. Epidemiological studies have linked vitamin D status to a number of chronic diseases. We aimed to examine the relationships between serum 25-hydroxyvitamin D (25(OH)D) and circulating thiol/disulfide redox status and biomarkers of inflammation. Design This was a cross-sectional study of N=693 adults (449 females, 244 males) in an apparently healthy, working cohort in Atlanta, GA. Plasma glutathione (GSH), cysteine (Cys), and their associated disulfides were determined with high performance liquid chromatography, and their redox potentials (Eh GSSG and Eh CySS) were calculated using the Nernst equation. Serum inflammatory markers included interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-α, assayed on a multiplex platform; and C-reactive protein (CRP), assayed commercially. Relationships were assessed with multiple linear regression analyses. Results Serum 25(OH)D was positively associated with plasma GSH (β ± SE: 0.002 ± 0.0004) and negatively associated with plasma Eh GSSG (β ± SE: −0.06 ± 0.01) and Cys (β ± SE: −0.01 ± 0.003) (P<0.001 for all); statistical significance remained after adjusting for age, gender, and race, percent body fat, and traditional cardiovascular risk factors (P=0.01-0.02). The inverse relationship between serum 25(OH)D and CRP was confounded by percent body fat, and full adjustment for covariates attenuated serum 25(OH)D relationships with other inflammatory markers to non-statistical significance. Conclusions Serum 25(OH)D concentrations were independently associated with major plasma thiol/disulfide redox systems, suggesting that vitamin D status may be involved in redox-mediated pathophysiology.

Vitamin D supplementation does not improve plasma thiol/disulfide homeostasis

“…Similar to the present results, Alvarez et al found that the vitamin D level in plasma was associated with the plasma thiol/disulfide redox system in healthy adults. 6 In another study with critically ill children, the oxidative cysteine and redox potential were lower in children with a sufficient level of vitamin D, but their glutathione (GSH), glutathione disulfide and glutamine levels were also low. 5 Thus, a low level of both oxidant and antioxidant parameters produced conflicting results.…”

“…Research has shown that vitamin D deficiency increases oxidative stress and protein oxidation . In adults, vitamin D concentration is associated with thiol/disulfide homeostasis …”

“…5 In adults, vitamin D concentration is associated with thiol/disulfide homeostasis. 6 Increased production of reactive oxygen species (ROS) causes oxidative stress, which is a potential condition for DNA, lipid and protein damage. Increased thiols (RSH) interacting with ROS immediately increase the formation of disulfide bond (RSSR).…”

Association between serum 25-hydroxyvitamin D levels and age-related cataracts

“…8 Vitamin D is positively associated with plasma glutathione, a major intracellular antioxidant, and with cysteine, a major extracellular antioxidant. 9 Moreover, vitamin D appears to catalyze glutathione production. 34 However, the trend analysis for the OR did not show a significant declining trend in the risk for cataracts in association with the higher serum 25-hydroxyvitamin D quintiles, suggesting the possibility of a poor dose-response relationship between serum 25-hydroxyvitamin D levels and cataracts.…”

Evaluation of socioeconomic status as a risk factor of pterygium using the Korean National Health and Nutrition Examination Survey 2010 to 2011

“…Vitamin D has generally been considered to have protective effects against chronic inflammatory diseases through its anti-inflammatory and antioxidative actions. [12] Several studies have suggested that vitamin D is inversely associated with ophthalmic diseases such as myopia, [13] age-related macular degeneration, [14] diabetic retinopathy, [15] and cataracts. However, Bonakdaran and Shoeibi [16] reported that vitamin D insufficiency was not related to risk factors of diabetic retinopathy.…”