The effect of vitamin D supplementation on tobacco-related disorders in individuals with a tobacco use disorder: a randomized clinical trial.

Vitamin D deficiency in cigarette smokers (CS) might associate with several complications, including metabolic deficits, depression and anxiety. This study evaluated the effects of vitamin D on mental health symptoms, nicotine misuse, and biomarkers of metabolic diseases in individuals with a tobacco use disorder. A randomized, double-blind, placebo-controlled trial was conducted with 60 CS subjects receiving either 50,000 IU vitamin D supplements (n = 30) or placebo (n = 30) every 2 weeks for 24-weeks. Nicotine misuse, mental health scale, and metabolic parameters were measured before and after the intervention in the CS subjects. Compared with the placebo-group, after the 24-weeks intervention, serum 25 (OH) vitamin D levels increased in the intervention group (ß 2.96; 95% CI, 0.91, 5.01; P = 0.006). In addition, vitamin D supplementation significantly improved Beck Depression Inventory (BDI) (ß -2.06; 95% CI, -3.84, -0.28; P = 0.02). In addition, vitamin D administration significantly decreased fasting plasma glucose (FPG) (ß -4.56; 95% CI, -8.94, -0.19; P = 0.04), insulin (ß -0.50; 95% CI, -0.88, -0.13; P = 0.009), and homeostasis model of assessment-estimated insulin resistance (HOMA-IR) levels (ß -0.21; 95% CI, -0.33, -0.08; P = 0.001). Furthermore, vitamin D resulted in a significant elevation in total antioxidant capacity (TAC) (ß 81.20; 95% CI, 18.30, 144.11; P = 0.01), and plasma glutathione (GSH) levels (ß 73.05; 95% CI, 18.56, 127.54; P = 0.01), compared with the placebo-group. Administration of vitamin D for 24-weeks to CS subjects had beneficial effects on symptoms of depression and several metabolic biomarkers. While this preliminary study suggests that vitamin D might have beneficial effects, its clinical efficacy in individuals with a tobacco use disorder should be further validated in future clinical trials.

Vitamin D supplementation attenuates the behavioral scores of neuropathic pain in rats.

Objective(s): Neuropathic pain due to lesion or dysfunction of the peripheral or central nervous system is often refractory to the conventional analgesics. Currently, there is no proven treatment to prevent or cure neuropathic pain. A recent surge of new data suggests the potential effects of vitamin D in the medical community. This study was designed to determine whether acute or chronic vitamin D administration was effective in alleviating symptoms of neuropathic pain in a rat model of neuropathic pain. Materials and Methods: Neuropathic pain was induced by chronic constriction injury (CCI) of the sciatic nerve in the rats that resulted in thermal hyperalgesia, mechanical, and cold allodynia. Results: Acute vitamin D injections (250, 500, and 1000 unit/kg i.p.) on the 7th, 14th, and 21st postoperative days could not attenuate mechanical and cold allodynia as well as heat hyperalgesia compared to CCI group. But when vitamin D (1000 unit/kg i.p.) administration was started on the first day after surgery and given daily until the 21st day, cold allodynia and heat hyperalgesia considerably were attenuated. However, no differences in paw withdrawal thresholds were observed. Conclusion: These results indicate that chronic vitamin D administrations can attenuate the behavioral scores of neuropathic pain in rats.