Clinical trial of the effects of vitamin D supplementation on psychological symptoms and metabolic profiles in maintenance methadone treatment patients

- This study has evaluated the effects of vitamin D intake in MMT patients.
- Vitamin D supplementation in MMT patients improved psychological symptoms.
- Vitamin D supplementation in MMT patients improved metabolic status.

BackgroundVitamin D deficiency may be associated with some complications including nonspecific musculoskeletal pain and periodontal disease in maintenance methadone treatment (MMT) patients. This study was designed to determine the effect of vitamin D supplementation on psychological symptoms and metabolic profiles in MMT patients.MethodsThis randomized, double-blind, placebo-controlled, clinical trial was carried out among 68 MMT patients. Participants were randomly allocated to receive either 50,000 IU vitamin D supplements (n = 34) or placebo (n = 34) every 2 weeks for 12 weeks. Fasting blood samples were taken at baseline and post-intervention to evaluate relevant variables.ResultsAfter the 12-week intervention, serum 25(OH) vitamin D levels significantly increased in the intervention group compared with the placebo group (+ 8.1 ± 4.9 vs. − 0.4 ± 3.0, P < 0.001). In addition, vitamin D supplementation significantly improved Pittsburgh Sleep Quality Index (− 1.5 ± 2.2 vs. − 0.2 ± 2.3, P = 0.02) and Beck Depression Inventory (− 4.8 ± 7.3 vs. − 1.5 ± 6.1, P = 0.04) compared with the placebo. Patients who received vitamin D supplements had significantly decreased fasting plasma glucose (− 7.5 ± 10.6 vs. + 0.3 ± 10.7 mg/dL, P = 0.004), serum insulin levels (− 3.6 ± 5.3 vs. − 0.9 ± 3.5 μIU/mL, P = 0.01), homeostasis model of assessment-insulin resistance (− 1.0 ± 1.3 vs. − 0.2 ± 0.7, P = 0.003), serum triglycerides (− 9.6 ± 30.8 vs. + 15.6 ± 30.2 mg/dL, P = 0.001), total- (− 8.7 ± 20.9 vs. + 11.0 ± 27.4 mg/dL, P = 0.001) and LDL-cholesterol (− 11.1 ± 17.9 vs. + 5.9 ± 27.5 mg/dL, P = 0.004) compared with the placebo. Additionally, vitamin D intake resulted in a significant decrease in serum high sensitivity C-reactive protein (− 2.2 ± 4.2 vs. + 2.0 ± 3.7 mg/L, P < 0.001), and significant increases plasma total antioxidant capacity (+ 26.2 ± 99.8 vs. − 86.3 ± 127.5 mmol/L, P < 0.001) and glutathione levels (+ 292.3 ± 172.4 vs. + 48.9 ± 208.9 μmol/L, P < 0.001) compared with the placebo. There was no significant effect of vitamin D supplementation on serum HDL-cholesterol, and other markers of insulin metabolism, inflammation and oxidative stress.ConclusionsTotally, taking 50,000 IU vitamin D supplement every 2 weeks for 12 weeks in MMT patients had beneficial effects on psychological symptoms and few metabolic profiles.