Effect of Oral Vitamin D on Sexual Function and Depressive Symptoms in Women with Sexual Dysfunction and Vitamin D Deficiency or Insufficiency: A Randomized Controlled Trial

Abstract

Abstract Background: Sexual dysfunction and depression in women are important health problems around the world. Vitamin D difficiency or insufficiency is very common among Iranian women. Therefore, given the limited number of studies on the effect of vitamin D on sexual function, and the inconsistent results about the effect of vitamin D on depression, the present study was conducted to determine the effect of vitamin D on sexual function and symptoms of depression in women with vitamin D deficiency (primary objective), and women with vitamin D insufficiency (secondary objective). Methods: This randomized placeb0-controlled clinical trial with four parallel arms was conducted on women aged 18-40 years with sexual dysfunction (57 with vitamin D deficiency and 23 with vitamin D insufficiency) covered by the public health centers in Tabriz. The participants were assigned to intervention and control groups by their serum vitamin D level (deficiency or insufficiency) using stratified (based on the use or non-use of hormonal contraceptives and depression status (two groups: 1-minor or mild, and 2-moderate)) block randomization, with block size of four and allocation ratio of 1:1. The participants with vitamin D deficiency were given two and those with vitamin D insufficiency were given one soft gels of vitamin D 2000 IU or placebo per day for three months. Before the intervention and three months of intervention, the demographic and social characteristics questionnaire, female Sexual function Index (FSFI) and Beck Depression Inventory 2 (BDI-II) were completed and Serum levels of 25-hydroxyvitamin D were measured. Independent t-test and ANCOVA were used for data analysis. Results: Mean serum vitamin D was 13.7 (SD 2.7) and 23.6 (SD 2.6) ng/ml, respectively, in women with vitamin D deficiency and insufficiency. After 3 months of intervention, there were significant differences between vitamin D and placebo groups neither in group of women with vitamin D deficiency, nor in those with vitamin D insufficiency, in terms of mean FSFI (adjusted mean difference (MD) 0.6, 95% confidence interval (CI) -0.9 to 2.1, P=.4; MD -2.0, 95% CI -5.5 to 1.6, P=.3, respectively), and BDI (MD 0.2, 95% CI -4.5 to 4.9, P=.9; MD 3.7, 95% CI -1.4 to 8.8, P=.15, respectively). Conclusion: Oral supplementation of vitamin D for three months does not significantly improve sexual function and depressive symptoms in the women with sexual dysfunction and vitamin D deficiency or insufficiency who have no severe depressive symptoms.