The effects of vitamin D and probiotic co-supplementation on mental health parameters and metabolic status in type 2 diabetic patients with coronary heart disease: A randomized, double-blind, placebo-controlled trial.

Background: This study was carried out to evaluate the effects of vitamin D and probiotic co-supplementation on mental health parameters and metabolic status in diabetic people with coronary heart disease (CHD).

Methods: This randomized, double-blind, placebo-controlled trial was carried out among 60 diabetic people with CHD, aged 45-85 years old. Subjects were randomly allocated into two groups to receive either 50,000 IU vitamin D every 2 weeks plus 8 × 10 CFU/g probiotic of Lactocare Zisttakhmir Co (n = 30) or placebo (n = 30) for 12 weeks. Fasting blood samples were obtained at baseline and after the 12-week intervention to determine metabolic profiles.

Results: After the 12-week intervention, compared with the placebo, vitamin D and probiotic co-supplementation resulted in significant improvements in beck depression inventory total score (-2.8 ± 3.8 vs. -0.9 ± 2.1, P = 0.01), beck anxiety inventory scores (-2.1 ± 2.3 vs. -0.8 ± 1.4, P = 0.009) and general health questionnaire scores (-3.9 ± 4.1 vs. -1.1 ± 3.4, P = 0.005). Compared with the placebo, vitamin D and probiotic co-supplementation resulted in significant reductions in serum insulin levels (-2.8 ± 3.8 vs. +0.2 ± 4.9 μIU/mL, P = 0.009), homeostasis model of assessment-estimated insulin resistance (-1.0 ± 1.6 vs. -0.1 ± 1.5, P = 0.02), and a significant increase in serum 25-OH-vitamin D (+11.8 ± 5.9 vs. +0.1 ± 1.4 ng/mL, P < 0.001), the quantitative insulin sensitivity check index (+0.03 ± 0.04 vs. -0.001 ± 0.01, P = 0.003) and serum HDL-cholesterol levels (+2.3 ± 3.5 vs. -0.5 ± 3.8 mg/dL, P = 0.004). In addition, changes in serum high sensitivity C-reactive protein (hs-CRP) (-950.0 ± 1811.2 vs. +260.5 ± 2298.2 ng/mL, P = 0.02), plasma nitric oxide (NO) (+1.7 ± 4.0 vs. -1.4 ± 6.7 μmol/L, P = 0.03) and plasma total antioxidant capacity (TAC) (+12.6 ± 41.6 vs. -116.9 ± 324.2 mmol/L, P = 0.03) in the supplemented group were significantly different from the changes in these indicators in the placebo group.

Conclusions: Overall, vitamin D and probiotic co-supplementation after 12 weeks among diabetic people with CHD had beneficial effects on mental health parameters, serum hs-CRP, plasma NO, TAC, glycemic control and HDL-cholesterol levels.

Clinical Trial Registration Number: http://www.irct.ir: IRCT2017073033941N4.