Effect of Vitamin D Therapy on Sexual Function in Women with Sexual Dysfunction and Vitamin D Deficiency: A Randomized, Double-Blind, Placebo Controlled Clinical Trial

PURPOSE: We investigated the effect of vitamin D therapy on sexual function in women with low vitamin D levels and sexual dysfunction. MATERIALS AND METHODS: We performed this randomized, double-blind, placebo controlled trial in women 18 to 45 years old with sexual dysfunction, defined as a FSFI (Female Sexual Functioning Index) score less than 26.55, and serum 25OHD less than 30 ng/ml. Participants received an intramuscular injection of 300,000 IU cholecalciferol or a placebo at baseline and then after 4 weeks. Sexual function was evaluated with the FSFI at baseline, and 4 and 8 weeks. The serum level of 25OHD was measured and depression symptoms were evaluated by the BDI (Beck Depression Inventory) at baseline and 8 weeks. RESULTS: A total of 38 women in each group completed the study. Serum 25OHD levels increased only in the cholecalciferol group by a mean ± SD of 14.4 ± 3.2 ng/ml (p <0.001). The FSFI score was higher in the intervention group at study week 4 (19.6 vs 16.3, p = 0.002) and week 8 (25.0 vs 17.1, p <0.001). The BDI score was significantly decreased only in the cholecalciferol group by a mean of -21.0 ± 12.3 (p <0.001). The effect of treatment on sexual function was independent of its effect on depression symptoms. CONCLUSIONS: Vitamin D therapy in women with sexual dysfunction and vitamin D deficiency can improve sexual function. This effect does not seem to be mediated by an improvement in depression symptoms

Slow deep breathing modulates cardiac vagal activity but does not affect peripheral glucose metabolism in healthy men.

Parasympathetic nervous system innervates peripheral organs including pancreas, hepatic portal system, and gastrointestinal tract. It thereby contributes to the regulation of whole-body glucose metabolism especially in the postprandial state when it promotes secretion of insulin and enhances its action in major target organs. We now aimed to evaluate the effect of parasympathetic modulation on human&nbsp;glucose metabolism. We used slow deep breathing maneuvers to activate the parasympathetic nervous system and tested for effects on metabolism during an oral glucose tolerance test in a randomized, controlled, cross-over trial in 15 healthy young men. We used projections towards the heart as a readout for parasympathetic activity. When analyzing heart rate variability, there was a significant increase of RMSSD (root mean square of successive differences) when participants performed slow deep breathing compared to the control condition, indicating a modulation of parasympathetic activity. However, no statistically significant effects on peripheral glucose metabolism or energy expenditure after the glucose tolerance test were detected. Of note, we detected a significant association between mean heart rate and serum insulin and C-peptide concentrations. While we did not find major effects of slow deep breathing on glucose metabolism, our correlational results suggest a link between the autonomic nervous system and insulin secretion after oral glucose intake. Future studies need to unravel involved mechanisms and develop potential&nbsp;novel treatment approaches for impaired insulin secretion in diabetes