Serum 25-hydroxyvitamin D levels and testosterone deficiency in middle-aged Korean men: a cross-sectional study

Impact of vitamin D supplementation as COVID-19 vaccine adjuvant on sperm parameters and sex hormones in men with idiopathic infertility: Two separate pre-post studies

OBJECTIVE

Vitamin D deficiency is a major problem for human health worldwide. The mechanisms of vitamin D in the male reproductive system are unknown. After coronavirus disease 2019 (COVID-19) vaccines were developed, doubts were raised about their possible effects on male fertility. Based on vitamin D's function in the immune system, its potential role as an adjuvant for COVID-19 vaccines is intriguing. The aims of this study were to assess the effects of vitamin D first on sperm parameters and sex hormones, and then as an immune adjuvant on sperm parameters and sex hormones after study participants had received their second doses of COVID-19 vaccines.

METHODS

Phase 1 (before the COVID-19 pandemic) included 72 men with idiopathic infertility, and phase 2 had 64 participants who received two doses of COVID-19 vaccines. Both groups were instructed to take 50,000 IU of vitamin D twice monthly for 3 months. Sperm parameters and sex hormones were assessed pre- and post-supplementation.

RESULTS

Regular vitamin D intake for 3 months significantly increased the participants' vitamin D levels (p=0.0001). Both phases showed a positive correlation between vitamin D intake and sperm parameters. Vaccination had no negative effects on sperm parameters and sex hormones. Vitamin D was associated with follicle-stimulating hormone (p=0.02) and testosterone (p=0.0001) in phase 2 after treatment.

CONCLUSION

Our results support vitamin D supplementation as an immune adjunct to COVID-19 vaccination for improving sperm parameters and hormone levels. COVID-19 vaccination is not harmful for male fertility potential, and vitamin D is an effective factor for male fertility.

Serum Vitamin D Deficiency and Male Infertility: A Relationship?

Background Male infertility is one of the major reproductive health concerns, causing a lot of distress for couples globally. Others have looked into its connection to vitamin D deficiency, but their findings are conflicting. Aim This study aimed to determine the relationship between male infertility and vitamin D deficiency among Nigerians. Method This analytical cross-sectional study was conducted among 132 men. A purposive sampling technique was employed to recruit 66 participants in the study (men with infertility) and control groups (men with proven fertility). Descriptive statistics were conducted, while the association between vitamin D level and sperm parameters was assessed using bivariate and regression modeling. A two-tailed test of the hypothesis was assumed, and the level of statistical significance was set at a P-value < 0.05. Results None of the participants had a serum vitamin D deficiency. However, the overall serum vitamin D insufficiency rate was 15%. The median vitamin D level for the total study population (both fertile and infertile) was 37.52 ng/ml (IQR: 32.1 - 51.69). This study demonstrated no association between serum vitamin D levels and male infertility, as well as no association between serum vitamin D levels and the quality of semen parameters. Conclusion There was no significant association between vitamin D levels, male infertility, and seminal fluid parameters. However, larger multi-center studies are recommended to provide further insights into this conclusion.

Effects of Vitamin D Supplementation on Testosterone, Prostate, and Lower Urinary Tract Symptoms: A Prospective, Comparative Study

PURPOSE

Several studies have associated the serum vitamin D level with total testosterone levels and the prostate volume. Herein, we investigated the effect of vitamin D supplementation on testosterone, prostate, and lower urinary tract symptoms (LUTS) in men.

MATERIALS AND METHODS

Men over 40 years of age diagnosed with a vitamin D deficiency (25[OH]D <20 ng/mL) who received vitamin D supplementation for one year were included in the study and administered 25,000 IU of cholecalciferol every 2 weeks. Prostate ultrasound, uroflowmetry, postvoid residual urine volume measurement, and serological tests (serum testosterone levels, etc.) were performed upon diagnosis and one year later. Participants also answered the International Prostate Symptom Score (IPSS) and Aging Males' Symptoms Scale (AMS) questionnaires.

RESULTS

A significant increase was observed in the vitamin D level following one year of vitamin D supplementation, with a significant decrease in the postvoid residual urine volume, total IPSS score and without a significant change in the prostate volume. Improved psychological subscale score of AMS questionnaire was observed with a statistical significance.

CONCLUSIONS

Vitamin D supplementation suppressed the increase in the prostate volume and improved the LUTS. Although there is no direct effect on serum testosterone levels, vitamin D supplementation helped improve hypogonadal symptoms.

Association Between 25-hydroxyvitamin D Levels and Testosterone in Healthy, Non-Obese, Young Adult, Filipino Men

Objective

This study seeks to determine the association between vitamin D and testosterone in healthy, adult Filipino males.

Methodology

This cross-sectional study included 110 healthy, non-obese, male volunteers aged 21-40. History and physical exam were taken, and blood was drawn for vitamin D, total testosterone (TT), sex hormone binding globulin (SHBG), albumin, insulin, fasting plasma glucose, and total cholesterol. Free testosterone (FT) was calculated. Vitamin D data were classified by status and TT, FT, and SHBG levels compared using the Kruskal-Wallis test. The associations of vitamin D levels with TT, FT, and SHBG were explored using multiple regression analysis.

Results

Vitamin D levels were sufficient in 3 (2.7%), insufficient in 17 (15.45%), and deficient in 90 (81.8%) of the sample. There were no significant differences in the mean TT (p = 0.7981), FT (p = 0.8768), nor SHBG (p = 0.1838) across vitamin D status. Vitamin D was not associated with TT nor FT before or after adjustment for age and age plus body mass index (BMI). Vitamin D was associated with SHBG before and after the aforementioned adjustments, but this became insignificant on sensitivity analysis.

Conclusion

There is no association between vitamin D and TT, FT nor SHBG in our cohort with deficient vitamin D levels.

The Association between Vitamin D and the Components of Male Fertility: A Systematic Review

OBJECTIVE

Previous systematic reviews of the effects of vitamin D on the components of male fertility have been inconclusive. This article systematically reviews the latest research to examine the relationship between vitamin D, semen quality parameters, and sex hormones production.

METHODS

MEDLINE, Cochrane, and Web of Science databases were searched using the appropriate keywords.

RESULTS

Observational studies indicate significant correlation between vitamin D levels and sperm parameters, with a particular emphasis on sperm motility, and partially suggest a relationship between higher serum testosterone and vitamin D levels. Additionally, interventional studies confirmed that vitamin D supplementation has a positive effect on sperm motility, especially progressive. However, most randomized clinical trials indicate that vitamin D treatment does not have any significant effect on testosterone or other hormone levels.

CONCLUSIONS

Although our findings add to the discussion regarding the effect of vitamin D on male fertility, there is still no solid evidence to support the use of vitamin D supplementation to improve the outcomes of patients with impaired sperm parameters and hormonal disorders. Additional dedicated clinical studies are needed to clarify the relationship between vitamin D and male fertility, along with its components.

Functional hypogonadism among patients with obesity, diabetes, and metabolic syndrome

Testosterone deficiency, defined as low total testosterone combined with physical, cognitive, and sexual signs and/or symptoms, is a common finding in adult men. Functional hypogonadism (FH) is defined as borderline low testosterone (T) secondary to aging and/or comorbid conditions such as diabetes, obesity, and/or metabolic syndrome. The relationship between FH and metabolic disorders is multifactorial and bidirectional, and associated with a disruption of the hypothalamic-pituitary-gonadal axis. Resolution of FH requires the correct diagnosis and treatment of the underlying condition(s) with lifestyle modifications considered first-line therapy. Normalization of T levels through dietary modifications such as caloric restriction and restructuring of macronutrients have recently been explored. Exercise and sleep quality have been associated with T levels, and patients should be encouraged to practice resistance training and sleep seven to nine hours per night. Supplementation with vitamin D and Trigonella foenum-graecum may also be considered when optimizing T levels. Ultimately, treatment of FH requires a multidisciplinary approach and personalized patient care.

Factors Defining the Association Between Vitamin D and Testosterone in Males With Type 2 Diabetes and Hypogonadism

OBJECTIVE

This study aimed to evaluate Serum 25-hydroxyvitamin D (25[OH]D) levels in diabetic men with and without hypogonadism and figured out the potential factors influencing the connection between vitamin D and testosterone.

METHODS

A total of 367 men with type 2 diabetes mellitus (T2DM) were investigated, including 254 men with normal gonadal function (Group 1) and 113 men with hypogonadism (Group 2). Men with hypogonadism were classified as either hypogonadotropic hypogonadism (Group 2a) or hypergonadotropic hypogonadism (Group 2b). Serum 25(OH)D levels were detected by liquid chromatography-tandem mass spectrometry in all cases. Morning total testosterone (TT), estradiol (E), dehydroepiandrosterone (DHEA), prolactin (PRL), sex hormone-binding globulin (SHBG), luteinizing hormone (LH), follicle-stimulating hormone (FSH), thyroid function, parathyroid and adrenal hormones, fasting blood glucose (FBG), fasting insulin (Fins) and hemoglobin A1c (HbA1c) were also assessed.

RESULTS

The prevalence of hypovitaminosis D in men with T2DM was up to 96.46%. Serum 25(OH)D levels were significantly lower in men with hypogonadism than those with eugonadism (16.65 ± 6.44 ng/mL vs. 18.17 ± 6.17 ng/mL, P=0.033). The lowest 25(OH)D level was observed in Group 2a (16.22 ± 6.52 ng/mL). After adjustment for the selected factors, serum 25(OH)D concentrations were shown to be positively correlated with TT concentrations (r=0.137, P=0.032). The relationship between 25(OH)D and testosterone was altered by age, duration of T2DM, body mass index, and HbA1c. Serum 25(OH)D level was positively associated with serum TT level in men with age <60 years (r=0.180, P=0.003), or with duration≥5 years (r=0.186, P=0.013), or with body mass index (BMI)≥28kg/m² (r=0.431, P=0.000), or with HbA1c≥9% (r=0.145, P=0.031).

CONCLUSIONS

These findings indicate that type 2 diabetes patients with hypogonadism have lower 25(OH)D levels than those without hypogonadism. There seems to be a positive association between the serum 25(OH)D and TT levels, which affected by age, duration, BMI, and HbA1c.

Insights into the perspective correlation between vitamin D and regulation of hormones: sex hormones and prolactin

Aim. Vitamin D is currently an exciting research target, besides its obvious role in calcium homeostasis and bone health, enormous work is being directed at examining the effects of this vitamin on various biological functions and pathological conditions.

Material and methods. The review of the literature and the analysis took about six months and was carried out through PubMed. This is a search engine opening mainly the MEDLINE database of trusted references. We called up all studies written in English that were published between the years 2004 to 2021 and that came through using the applied search terms, and analysed all those that met the criteria.

Results. The endocrine system with its many glands and hormones and their essential roles in the maintenance of normal body functioning cannot be far from interactions with vitamin D. Male and female sex hormones are no exceptions and many studies have investigated the correlations between these hormones and vitamin D. As such, direct and indirect relationships have been found between vitamin D, its receptors or one of its metabolising enzymes with sex hormones and the development of reproductive organs in males and females.

Conclusion. This review summarises the research investigating the associations of vitamin D with sex hormones and reproductive organs in males and females, and thus may pave the road for future studies that will investigate the clinical significance of vitamin D in the management of reproductive system disorders. Despite some conflicting results about the relationship between VD and the effectiveness of the reproductive system, many studies confirm the presence of receptors for this vitamin in the reproductive system, and this supports the direct or indirect relationship between VD and prolactin or VD and testosterone through PO4 and Ca2+ homeostasis, or production of osteocalcin. Therefore, VD is positively associated with semen quality and androgen status. Furthermore, a direct relationship between VD and the production of progesterone, estrogen and estrone in human ovarian cells has been supported by many studies.

Vitamin D, testosterone and depression in middle-aged and elderly men: a systematic review

Depression is one of the common psychiatric disorders during elderly. This systematic review aims to present the relationship between vitamin D deficiency, depression and testosterone serum concentration in the middle-aged and elderly men. We performed a comprehensive search in the Google Scholar, PubMed, ProQuest, Web of Science, Cochrane, Science Direct, and Scopus databases to collect any relevant published studies. The data of the articles that had been investigated the relationship between depression and 25-hydroxy vitamin D (25[OH]D) serum concentration (nine studies), or testosterone and 25[OH]D (six studies), as the primary outcomes, were included in our review. The results of the cohort and cross-sectional studies have shown that vitamin-D deficiency is associated with the incidence of depression in older men. In addition, documents have reported the positive association between vitamin D and testosterone, and previous studies have shown that testosterone can involve in the mood. We have proposed scientific mechanisms that have shown vitamin D may also play a protective role in depression through its effect on the testosterone. Therefore, it is a low risk and safe recommendation for the middle-aged and elderly men to use the vitamin D supplement or exposure to the sunlight to prevent depression.

Is there a relationship between serum vitamin D and semen parameters? A cross-sectional sample of the Iranian infertile men

BACKGROUND

Recent studies suggest that serum vitamin D may be associated with semen parameters. In the present cross-sectional study, we attempted to investigate the association between serum vitamin D levels and semen parameters among Iranian sub-fertile men.

RESULTS

A total of 350 infertile men recruited for this cross-sectional study using a simple random sampling method with a mean age of 34.77 years old, body mass index of 26.67 kg/m², serum vitamin D of 20.17 ng/ml, semen volume of 3.82 mL, sperm count of 44.48 (10⁶/mL), sperm total motility of 38.10 %, and morphologically normal sperm of 7.0 %. After controlling for potential confounders, serum vitamin D was positively associated with semen volume (β = 0.63, 95 % CI: 0.06, 1.20), sperm count (β = 14.40, 95 % CI: 4.56, 24.25), sperm total motility (β = 18.12, 95 % CI: 12.37, 23.86), and sperm normal morphology (β = 1.95, 95 % CI: 1.07, 2.83).

CONCLUSIONS

The present findings suggest that higher serum vitamin D levels are positively associated with higher semen volume, sperm count, sperm total motility, and normal morphology rate. These findings, however, do not specify a cause-and-effect relationship, and there is a need for further research in this area to understand whether vitamin D supplementation can improve semen parameters.

Correlative studies on vitamin D and total, free bioavailable testosterone levels in young, healthy men

The relationship between vitamin D levels and testicular hormonal function in men has not been clearly established. Therefore, we aimed to investigate the relationship between deficiency/insufficiency levels of 25(OH)D and luteinizing hormone (LH), follicle-stimulating hormone (FSH), total (TT), free (FT), and bioavailable testosterone (BT), and sex hormone binding globulin (SHBG) in young, healthy men. We enrolled 176 healthy, active young men aged 18–35 years from a genetically homogenous population of Lower Silesia, Poland. Serum levels of 25(OH)D, LH, FSH, and TT were measured by electrochemiluminescence (ECLIA). FT levels were measured by enzyme-linked immunosorbent assay (ELISA). BT levels were calculated from TT, SHBG, and albumin. SHBG was measured by chemiluminescent immunoassay CLIA. We did not find any significant differences between the mean hormonal values (LH, FSH, TT, FT, BT, and SHBG) and the status of 25(OH)D level (deficient and insufficient). Based on our results, we concluded that there is no relationship between deficient and insufficient 25(OH)D concentration and androgen levels in young, healthy men.

Revised manuscript R2, clean version are serum levels of 25-hydroxy vitamin D reduced following orchiectomy in testicular cancer patients?

Background

The testis represents one place where the progenitor of vitamin D is converted into its active form. Loss of one testis was suggested to result in reduced vitamin D serum levels. Vitamin D deficiency would represent a significant health problem in the long-term course of patients with testicular germ cell tumors (GCTs) since most of them survive. The purpose of this study was to look to the serum 25(OH)-Vitamin D (25OHD) levels in patients with GCTs before and after orchiectomy. A total of 177 GCT patients underwent measurements of serum 25OHD levels, thereof 83 with preoperative measurements and 94 with measurements at six particular time-points from immediate postoperatively to >24 months. Longitudinal assessments of 25OHD serum levels were performed in individual patients with repeated measurements. A second analysis involved patient cohorts with measurements at six postoperative time-points. Serum levels of patients were also compared with 2 control groups, one consisting of 84 patients with non-neoplastic testicular diseases and another with 237 patients with non-neoplastic urologic diseases. We also looked to associations of 25OHD levels with levels of testosterone, follicle stimulating hormone (FSH), age, histology of GCT and season. Descriptive statistical methods were employed to compare groups and to analyze changes over time.

Results

Normal serum levels of 25OHD were found in 21.7%, 23.1%, 20.2%, 21.9% in GCT patients preoperatively, after >2 years, in control group 1 and control group 2, respectively. Levels were significantly higher in spring and summer, but no association was found with other parameters. We found a significant transient decrease of 25OHD levels with a nadir at 6-12 months after orchiectomy and a recovery thereafter.

Conclusion

Contrasting with previous studies we found no permanent reduction of serum 25OHD levels after orchiectomy but transient postoperative drop of 25OHD levels. There were no associations of 25OHD levels with age, and levels of testosterone or FSH. Our results may point to a particular role of the testis in vitamin D metabolism and may thus enhance the understanding of the diverse physiological roles of the testis.

Relationship of Vitamin D status with testosterone levels: a systematic review and meta-analysis

PURPOSE

Despite a biological plausibility of a direct link between low vitamin D and androgen deficiency, the association remains inconclusive in epidemiological studies. Therefore, this systematic review and meta-analysis of case-control studies aim to assess whether and in what populations such an association can be demonstrated.

METHODS

A systematic search was performed in PubMed, EMBASE, Cochrane Library, Web of science, Science Direct, and CINAHL. Standardized mean differences (SMDs) and 95% confidence intervals (CIs) in total testosterone (TT) levels between men with 25-hydroxyvitamin D (25(OH)D) <20 and ≥20 ng/mL were combined using random-effects models. Funnel plot and trim-and-fill analysis were used to assess publication bias. Heterogeneity source was explored by a sub-group analysis according to health-related characteristics of the study populations.

RESULTS

Eighteen included studies collectively gave information on 9892 men with vitamin D deficiency and 10,675 controls. The pooled SMD revealed a slight, albeit just significant, positive association between 25(OH)D and TT (pooled SMD: -0.23, 95% CI: -0.45 to -0.01; P = 0.04) with a large between-study heterogeneity (I² = 98%, P_{for heterogeneity} < 0.00001). At the sub-group analysis, a significant positive association, along with noticeable decrease in heterogeneity, could only be demonstrated in studies of patients with frailty states (pooled SMD: -0.19; 95% CI: -0.27, -0.10,  P < 0.0001; I² = 51%, P_{for heterogeneity} = 0.06). A sensitivity analysis revealed a high stability of the result and the trim-and-fill adjustment for publication bias did not affect pooled estimate.

CONCLUSIONS

Both hypovitaminosis D and androgen deficiency should be regarded as markers of a poor health status, sharing common underlying aetiologies and risk factors.

Evaluation of the effect of vitamin D3 supplementation on quantitative and qualitative parameters of spermograms and hormones in infertile men: A Randomized controlled trial

BACKGROUND

25-Hydroxy Vitamin D3 is known to have an effect on reproductive system in both genders and may change the semen parameters in men.

OBJECTIVE

Our study aimed to evaluate the effect of oral vitamin D3 supplementation on spermogram quantitative and qualitative parameters in infertile men.

MATERIALS AND METHODS

This study was a triple-blind randomized controlled trial involving 62 infertile men with impaired spermatogonial tests. They were randomly divided into placebo and D3-supplemented groups. Spermograms and tests for LH (Luteinizing Hormone), FSH (Follicle Stimulating Hormone), TT (Total Testosterone), FT (Free Testosterone), SHBG (Sex Hormone Bonding Globulin), FAI (Free Androgen Index) and vitamin D3 levels were performed before and after the intervention.

RESULTS

There were no significant differences between the two groups in parameters of the spermograms or serum levels of LH, FSH, TT, and FAI. In the intervention group, SHBG was significantly decreased after intervention (p = 0.01) and there was a significant increase in FT in the placebo group (p = 0.03).

CONCLUSION

The intake of vitamin D3 did not change the quality and quantity of spermograms and serum levels of LH, FSH, TT, and FAI but affected FT and SHBG. Further studies are still needed to clarify the biological role of vitamin D3 on fertility particularly on male fertility. This study lays a foundation for more extensive studies on male infertility.

Reviewing the Evidence on Vitamin D Supplementation in the Management of Testosterone Status and Its Effects on Male Reproductive System (Testis and Prostate): Mechanistically Dazzling but Clinically Disappointing

PURPOSE

Vitamin D supplementation has been suggested to increase testosterone levels. The primary purpose of this literature review was to critically assess the physiologic effects of vitamin D supplementation on serum testosterone concentrations in men and the secondary purpose was to evaluate the feasibility of vitamin D status toward urologic health (testis and prostate).

METHODS

A structured literature review was performed using the Cochrane, MEDLINE, and Web of Science databases. The literature search encompassed studies published between 2011 and 2019.

FINDINGS

Observational studies suggest an association between higher testosterone and serum vitamin D concentrations. Conversely, most randomized clinical trials that investigated the effect of vitamin D administration on testosterone levels have failed to detect any significant effect. Physiologically, vitamin D is engaging in spermatogenesis, but it remains unclear whether vitamin D is a determinant of fertility. With prostate support, the management of vitamin D status has been associated with a decreased prevalence of benign prostatic hyperplasia and symptoms (ie, lower urinary tract symptoms). However, with prostate cancer, there is a paucity of evidence pertaining to vitamin D supplementation.

IMPLICATIONS

Mechanistically, vitamin D exhibits essential roles in the testis and prostate; otherwise, there is no apparent evidence to support the use of vitamin D supplementation to increase testosterone levels and to improve clinical outcomes related to the male reproductive system.

The effect of vitamin D on sperm motility and the underlying mechanism

Vitamin D deficiency is a common health issue around the world. We therefore evaluated the associations of semen quality with both serum and seminal plasma vitamin D levels and studied the mechanisms underlying these by incubating spermatozoa with 1,25(OH)₂D in vitro. Two hundred and twenty-two men were included in our study. Vitamin D was detected using an electrochemiluminescence method. Spermatozoa used for in vitro experiments were isolated by density gradient centrifugation. Positive relationships of serum 25(OH)D with semen volume and seminal plasma fructose were identified. Seminal plasma 25(OH)D level showed no relationship with serum 25(OH)D level, while it was inversely associated with sperm concentration and positively correlated with semen volume and sperm kinetic values. In vitro, sperm kinetic parameters increased after incubation with 1,25(OH)₂D, especially upon incubation for 30 min with it at a concentration of 0.1 nmol l⁻¹. Under these incubation conditions, the upward migration of spermatozoa increased remarkably with increasing adenosine triphosphate (ATP) concentration. The concentration of cyclic adenosine monophosphate (cAMP) and the activity of protein kinase A (PKA) were both elevated, and the PKA inhibitor, N-[2-(p-Bromocinnamylamino)ethyl]-5-isoquinolinesulfonamide dihydrochloride (H89) reversed the increase of ATP production. The concentrations of cytoplasmic calcium ions and nicotinamide adenine dinucleotide (NADH) were both enhanced, while mitochondrial calcium uniporter (MCU) inhibitor, Ruthenium 360 (Ru360) did not reverse the increase of ATP production. Therefore, seminal plasma vitamin D may be involved in regulating sperm motility, and 1,25(OH)₂D may enhance sperm motility by promoting the synthesis of ATP both through the cAMP/PKA pathway and the increase in intracellular calcium ions.

Vitamin D and Male Erectile Function: An Updated Review

Literature support that vitamin-D is important for different systems of the human body including, but not limited to endocrine and immune systems, vasculature and endothelial function of the body. Male erectile function depends on many factors and can be perceived as a health indicator of the body. Epidemiological data have shown that vitamin-D deficiency is also associated with erectile dysfunction. In this review, our aim is to interpret the mechanisms by which vitamin-D might regulate anatomy and physiology of penis. Evidence showed that vitamin-D is needed for an adequate erectile function. Briefly, vitamin-D is crucial for a better healthy body and sexual activity.

Sex Differences of Vitamin D Status across BMI Classes: An Observational Prospective Cohort Study

Growing evidence reported that vitamin D deficiency is a common finding in obesity. Vitamin D status also seems to be sex-related, although little is known regarding this association. Therefore, the aim of this study was to investigate the sex-related differences of serum 25OH vitamin D (25OHD) concentrations across body mass index (BMI) classes and, if there were any differences, whether they could be explained by sex-related differences in body composition. We enrolled 500 subjects (250 males, age 37.4 ± 11.8 years; 250 females, age 36.6 ± 11.8 years). Body composition was assessed by bioelectrical impedance analysis (BIA) phase-sensitive system. Serum 25OHD concentration was quantified by a direct, competitive chemiluminescence immunoassay. Vitamin D deficiency was defined as a serum 25OHD concentrations < 20 ng/mL (50 nmol/L). Stratifying the sample population according to sex and BMI categories, 25OHD concentrations were significantly higher in males compared to females in all BMI classes and decreased along with the increase of BMI values. Females with vitamin D deficiency had higher fat mass (FM) % compared to males with vitamin D deficiency. The 25OHD concentrations inversely correlated with FM % in both sexes. In a multiple regression analysis model, sex, FM %, and BMI were predictive factors of 25OHD concentration. In conclusion, our study suggests that 25OHD concentrations were lower in females than males across all BMI categories. Given the tight correlation between 25OHD concentrations and FM %, it can be hypothesized that the lower 25OHD concentrations in females than males can be explained by the fact that females have a higher amount of fat than males.

Towards a comprehensive etiopathogenetic and pathophysiological theory of multiple sclerosis

Background: Multiple sclerosis (MS) is a neurodegenerative disease caused by dysfunction of the immune system that affects the central nervous system (CNS). It is characterized by demyelination, chronic inflammation, neuronal and oligodendrocyte loss and reactive astrogliosis. It can result in physical disability and acute neurological and cognitive problems. Despite the gains in knowledge of immunology, cell biology, and genetics in the last five decades, the ultimate etiology or specific elements that trigger MS remain unknown. The objective of this review is to propose a theoretical basis for MS etiopathogenesis.Methods: Search was done by accessing PubMed/Medline, EBSCO, and PsycINFO databases. The search string used was "(multiple sclerosis* OR EAE) AND (pathophysiology* OR etiopathogenesis)". The electronic databases were searched for titles or abstracts containing these terms in all published articles between January 1, 1960, and June 30, 2019. The search was filtered down to 362 articles which were included in this review.Results: A framework to better understand the etiopathogenesis and pathophysiology of MS can be derived from four essential factors; mitochondria dysfunction (MtD) & oxidative stress (OS), vitamin D (VD), sex hormones and thyroid hormones. These factors play a direct role in MS etiopathogenesis and have a modulatory effect on many other factors involved in the disease.Conclusions: For better MS prevention and treatment outcomes, efforts should be geared towards treating thyroid problems, sex hormone alterations, VD deficiency, sleep problems and melatonin alterations. MS patients should be encouraged to engage in activities that boost total antioxidant capacity (TAC) including diet and regular exercise and discouraged from activities that promote OS including smoking and alcohol consumption.

Gender Differences in Vitamin D Status in China

Background

Vitamin D insufficiency is widespread in China. Various factors influence vitamin D level in the body. The present study investigated vitamin D status of residents in Jinzhong city, China, and analyzed the influence of gender on vitamin D status.

Material/Methods

In this cross-sectional study, 302 participants (176 men and 126 women) were recruited. Anthropometric data (body circumferences and height, weight) were collected, and serum vitamin D concentration was tested.

Results

Inadequate levels of vitamin D were found in 69% of men and 75% of women. Women’s 25(OH)D level (38.40±12.37 nmol/l) was substantially lower than that of the men (43.49±14.78 nmol/l) (p<0.01). The young women group had the lowest vitamin D level, which was even significantly below that of the elderly women group. Multiple linear regression analysis showed gender was significantly associated with vitamin D status (p<0.01).

Conclusions

Vitamin D deficiency is common in residents of Jinzhong during the winter. Compared to men, women are more prone to have inadequate vitamin D levels.

Vitamin D and Male Fertility: An Updated Review

To date, the key role of vitamin D in male reproductive system has been suggested, since the expression of vitamin D receptors and metabolizing enzymes was demonstrated in the testis and spermatozoa. Nevertheless, a general consensus about the role of vitamin D in male fertility is still debated. The aim of this review is to provide an updated systematic revision of the current available literature, discussing the experimental and clinical evidence on the role of vitamin D in the regulation of testis hormone production, seminal parameters and male fertility. The consequences of vitamin D deficiency on serum levels of testicular hormones have been analysed by several observational and interventional studies, with controversial results. Equally, the experimental researches not were able to state a certain relationship between vitamin D status and testis hormone production. Possible bias, including age, body mass index, and baseline vitamin D status justified the differences among studies. As well as concerning the effect of vitamin D on semen parameters, most of the studies agreed in the possibility that vitamin D might have a positive effect on human male fertility potential, particularly through better sperm motility. Regarding pregnancy outcomes, normal level of vitamin D seems to be related to better pregnancies. However, all the previous studies displayed a wide heterogeneity in study design, population, methodology, and cut off values used for the evaluation of vitamin D status. Future studies are needed to better clarify the exact role of vitamin D on hormonal and seminal panel in both fertile and infertile men.

Prevalence of Age-Associated Testosterone Deficiency Syndrome in Indian Population

Testosterone deficiency syndrome (TDS) is a gradual age-related phenomenon that occurs in a large proportion of the aging male population. This current prospective study was done with the objective to estimate the prevalence of age-associated TDS in India and its clinical profile. A total of 800 male patients aged ≥40 year were approached to participate in the study. A brief history and focused examination was done. Based on our exclusion criteria, 55 patients were excluded. Androgen deficiency in aging male (ADAM) questionnaire was administered to all remaining 745 patients. Out of these 745 patients, ADAM-positive (symptomatic TDS) patients were found to be 359 and enrolled in the study. In all ADAM-positive patients, serum testosterone levels were measured. Prevalence of symptomatic TDS in study population was found to be 48.18%. Mean total and free testosterone level of symptomatic TDS population were 3.287 ± 1.494 ng/ml (1.12–9.61) and 7.476 ± 2.902 pg/ml (2.18–21.76), respectively. Prevalence of biochemically confirmed TDS among symptomatic TDS population was 60.17%. Prevalence of TDS increases progressively with each decade of life (p=0.034). Prevalence was higher in patients with diabetes, hypertension, coronary artery disease, obesity, and metabolic syndrome. TDS is a real phenomenon with a prevalence of 28.99% in our study population.

Current vitamin D status in European and Middle East countries and strategies to prevent vitamin D deficiency: a position statement of the European Calcified Tissue Society

Vitamin D deficiency (serum 25-hydroxyvitamin D (25(OH)D) <50 nmol/L or 20 ng/mL) is common in Europe and the Middle East. It occurs in <20% of the population in Northern Europe, in 30-60% in Western, Southern and Eastern Europe and up to 80% in Middle East countries. Severe deficiency (serum 25(OH)D <30 nmol/L or 12 ng/mL) is found in >10% of Europeans. The European Calcified Tissue Society (ECTS) advises that the measurement of serum 25(OH)D be standardized, for example, by the Vitamin D Standardization Program. Risk groups include young children, adolescents, pregnant women, older people (especially the institutionalized) and non-Western immigrants. Consequences of vitamin D deficiency include mineralization defects and lower bone mineral density causing fractures. Extra-skeletal consequences may be muscle weakness, falls and acute respiratory infection, and are the subject of large ongoing clinical trials. The ECTS advises to improve vitamin D status by food fortification and the use of vitamin D supplements in risk groups. Fortification of foods by adding vitamin D to dairy products, bread and cereals can improve the vitamin D status of the whole population, but quality assurance monitoring is needed to prevent intoxication. Specific risk groups such as infants and children up to 3 years, pregnant women, older persons and non-Western immigrants should routinely receive vitamin D supplements. Future research should include genetic studies to better define individual vulnerability for vitamin D deficiency, and Mendelian randomization studies to address the effect of vitamin D deficiency on long-term non-skeletal outcomes such as cancer.

Investigating the effect of testosterone by itself and in combination with letrozole on 1,25-dihydroxy vitamin D and FGF23 in male rats

BACKGROUND

Testosterone deficiency might be associated with vitamin D levels in hypogonadal men, but it is not clear whether testosterone can affect vitamin D and fibroblast growth factor-23 (FGF23), either directly or indirectly via aromatization to estradiol. We aimed to investigate the role of testosterone on vitamin D metabolism and serum FGF23 in male rats.

METHODS

A total of 48 male rats were divided into 4 equal groups: sham; O, orchiectomy; O + T, orchiectomized rats treated with testosterone; and O + T + L, orchiectomized rats treated with combination of testosterone and letrozole. We compare the vitamin D metabolism biochemical parameters in these four groups, before and after the study.

RESULTS

We detected a significant reduction in 25-hydroxyvitamin D (25(OH)D), vitamin D binding protein (DBP), FGF23, and 1,25-dihydroxyvitamin D (1,25(OH)2D) serum level in O group compared to sham group (p = 0.004, p = 0.009, p < 0.001 and p < 0.001, respectively), and a significant increase in serum phosphorus, parathyroid hormone (PTH), and alkaline phosphatase (ALP) levels in orchiectomized rats in comparison to sham group (p < 0.001, p = 0.022, and p = 0.006, respectively). However, these changes were corrected by testosterone replacement in O + T and O + T + L groups. In addition, we found that DBP and 1,25(OH)2D serum levels were significantly higher in O + T group in comparison to O + T + L group (p = 0.030 and p = 0.026, respectively).

CONCLUSIONS

Testosterone plays a significant role on regulating 25(OH)D, DBP, FGF23, phosphate (Phos), PTH, and 1,25(OH)2D serum levels in male rats. Also, testosterone has a potent effect on 1,25(OH)2D and DBP by its conversion to estradiol.

Association of serum content of 25-hydroxy vitamin D with semen quality in normozoospermic and oligoasthenoteratozoospermic men

BACKGROUND

Vitamin D has multifaceted function in human reproductive physiology. It has been revealed that vitamin D is involved in spermatogenesis, and semen quality can be linked to vitamin D status in men.

OBJECTIVE

Evaluating the correlation of 25-hydroxy vitamin D (25-OHD) levels in serum with basic and advanced semen parameters and essential determinants of spermatozoa function.

MATERIALS AND METHODS

Participants were categorized, based on semen parameters, into normozoospermic (NS) and oligoasthenoteratozoospermic (OAT) men. Serum level of 25-OHD was measured. Apoptotic status of spermatozoa, mitochondrial membrane potential and reactive oxygen species content of semen were assessed.

RESULTS

Difference of 25-OHD concentration in serum of NS men versus OAT ones did not meet significance threshold. DNA fragmentation, reactive oxygen species content of semen and mitochondrial membrane potential state revealed significant difference between NS and OAT subjects. There were no significant differences in basic and functional semen parameters when men were stratified based on serum 25-OHD level. Taking both 25-OHD and semen categories (NS and OAT) into consideration did not indicate any significant difference in studied parameters. Total motility of spermatozoa was positively correlated with serum concentration of 25-OHD in all studied subjects. In addition, normal morphology of spermatozoa in NS men revealed a positive and significant correlation with levels of 25-OHD in serum.

CONCLUSION

Vitamin D may affect motility and morphology of spermatozoa. Lower content of serum vitamin D may affect fertility of men and should be considered in examination of men with abnormal spermogram.

Effects of Vitamin D Restricted Diet Administered during Perinatal and Postnatal Periods on the Penis of Wistar Rats

Vitamin D deficiency is common in pregnant women and infants. The present study aimed to investigate the effects of vitamin D restricted diet on the Wistar rats offspring penis morphology. Mother rats received either standard diet (SC) or vitamin D restricted (VitD) diet. At birth, offspring were divided into SC/SC (from SC mothers, fed with SC diet) and VitD/VitD (from VitD mothers, fed with VitD diet). After euthanasia the penises were processed for histomorphometric analysis. The VitD/VitD offspring displayed metabolic changes and reduction in the cross-sectional area of the penis, corpus cavernosum, tunica albuginea, and increased area of the corpus spongiosum. The connective tissue, smooth muscle, and cell proliferation percentages were greater in the corpus cavernosum and corpus spongiosum in the VitD/VitD offspring. The percentages of sinusoidal spaces and elastic fibers in the corpus cavernosum decreased. The elastic fibers in the tunica albuginea of the corpus spongiosum in the VitD/VitD offspring were reduced. Vitamin D restriction during perinatal and postnatal periods induced metabolic and structural changes and represented important risk factors for erectile dysfunction in the penis of the adult offspring. These findings suggest that vitamin D is an important micronutrient in maintaining the cytoarchitecture of the penis.

Vitamin D, PCOS and androgens in men: a systematic review

BACKGROUND

Accumulating evidence from animal and human studies suggests that vitamin D is involved in many functions of the reproductive system in both genders.

AIM

The aim of this review was to provide an overview on the effects of vitamin D on polycystic ovary syndrome (PCOS) in women and androgen metabolism in men.

METHODS

We performed a systematic literature search in PubMed for relevant English language publications published from January 2012 until September 2017.

RESULTS AND DISCUSSION

The vitamin D receptor and vitamin D-metabolizing enzymes are found in reproductive tissues of women and men. In women, vitamin D status has been associated with several features of PCOS. In detail, cross-sectional data suggest a regulatory role of vitamin D in PCOS-related aspects such as ovulatory dysfunction, insulin resistance as well as hyperandrogenism. Moreover, results from randomized controlled trials (RCTs) suggest that vitamin D supplementation may be beneficial for metabolic, endocrine and fertility aspects in PCOS. In men, vitamin D status has been associated with androgen levels and hypogonadism. Further, there is some evidence for a favorable effect of vitamin D supplementation on testosterone concentrations, although others failed to show a significant effect on testosterone levels.

CONCLUSION

In summary, vitamin D deficiency is associated with adverse fertility outcomes including PCOS and hypogonadism, but the evidence is insufficient to establish causality. High-quality RCTs are needed to further evaluate the effects of vitamin D supplementation in PCOS women as well as on androgen levels in men.

Impact of metabolic status on the association of serum vitamin D with hypogonadism and lower urinary tract symptoms/benign prostatic hyperplasia

OBJECTIVE

The objective of this study is to investigate the impact of metabolic status on associations of serum vitamin D with hypogonadism and lower urinary tract symptoms (LUTS)/benign prostatic hyperplasia (BPH).

PATIENTS AND METHODS

A total of 612 men underwent physical examination, biochemical/hormonal blood testing, and transrectal prostate ultrasound. Moreover, the subjects filled out standard questionnaires for identification and grading of LUTS and hypogonadism symptoms. Parameters were statistically compared with independent t-tests and correlation analyses.

RESULTS

Vitamin D levels positively correlated with total testosterone (TT) but not with prostate volume or International Prostate Symptom Score (IPSS). Patients with metabolic syndrome had significantly lower vitamin D levels, which were not correlated with TT, prostate volume, or IPSS. However, vitamin D was positively correlated with TT, and negatively correlated with prostate volume and quality-of-life IPSS in subjects without metabolic syndrome.

CONCLUSION

The clinical usefulness of vitamin D for treatment of hypogonadism or LUTS/BPH varies according to metabolic status.

Association Between Vitamin D, Reproductive Hormones and Sperm Parameters in Infertile Male Subjects

Background: The prevalence of infertility and vitamin D deficiency is common in Pakistan. Therefore, our study aims were to assess and compare Vitamin D; 25-hydroxyvitamin (25OHD) and reproductive hormone levels in male fertile and infertile subjects with normal and abnormal sperm parameters. Furthermore, the study is aimed to explore the association of 25OHD levels with these sperm parameters in a selected population of Karachi, Pakistan. Methods: The cross-sectional study was carried out from August 2016 till December 2017, 313 study subjects were recruited from an Infertile Clinic from Islamabad, Pakistan, and the general population. First, we took the couples' history of parenting and then carried out a semen analysis and infertile and fertile male subjects were then subgrouped into "normal" and "altered sperm parameter/s." Forward linear regression was done for selection of 25OHD as a significant predictor of sperm parameters. Results: The median values of the total count, motility, morphology as well as serum 25OHD were significantly higher in the group with "normal" (186) as compared to subjects (127) in "abnormal sperm parameters" group. The 25OHD levels were significantly high in males with "normal sperm parameters"; 80.90 ± 23.33 nmol/L vs. "altered sperm parameter/s," 64.68 ± 24.21 nmol/L (mean ± SD) with p < 0.001. Serum testosterone level had a significant positive correlation with 25OHD while LH had a significant negative correlation with 25OHD (p < 0.001), and FSH level had a non-significant negative correlation with 25OHD. Results of regression model showed one unit increase of motility would give 0.15-unit positive significant impact on 25OHD; 20% variation in 25OHD was explained by the total count, motility, and morphology, while the model was adjusted for BMI. Conclusion: The impact of 25OHD levels on sperm parameters can be emphasized on the basis of detection of its high serum levels in "normal" subjects in both fertile as well as infertile males in comparison to subjects that had altered sperm parameters; total sperm count, motility, and normal morphology. The considerably positive association between 25OHD, testosterone, total count, motility, and morphology further accentuates its impact on normal spermatogenesis and the male reproductive functions required for acquiring fertility.

Possible influence of vitamin D on male reproduction

Vitamin D is a versatile signaling molecule with an established role in the regulation of calcium homeostasis and bone health. In recent years the spectrum of vitamin D target organs has expanded and a reproductive role is supported by the presence of the vitamin D receptor (VDR) and the vitamin D metabolizing enzymes in the gonads, reproductive tract, and human spermatozoa. Interestingly, expression levels of VDR and the vitamin D inactivating enzyme CYP24A1 in human spermatozoa serve as positive predictive markers of semen quality and are higher expressed in spermatozoa from normal than infertile men. VDR mediates a non-genomic increase in intracellular calcium concentration, sperm motility, and induces the acrosome reaction. Furthermore, functional animal model studies have shown that vitamin D is important for sex steroid production, estrogen signaling, and semen quality. Cross-sectional clinical studies have supported the notion of a positive association between serum 25-hydroxyvitamin D (25-OHD) level and semen quality in both fertile and infertile men. However, it remains to be determined whether this association reflects a causal effect. The VDR is ubiquitously expressed and activated vitamin D is a regulator of insulin, aromatase, and osteocalcin. Hence, it is plausible that the influence of vitamin D on gonadal function may be mediated indirectly through other vitamin D regulated endocrine factors. Recent studies have indicated that vitamin D supplementation may be beneficial for couples in need of assisted reproductive techniques as high serum vitamin D levels were found to be associated with a higher chance of achieving pregnancy. Randomized clinical trials are needed to determine whether systemic changes in vitamin D metabolites can influence semen quality, fertility, and sex steroid production in infertile men. In this review known and possible future implications of vitamin D in human male reproduction function will be discussed.

Seasonal Variations and Correlations between Vitamin D and Total Testosterone Levels

Background

Some studies have provided evidence for a possible association between vitamin D and testosterone levels; however, the evidence from studies in Koreans is inconsistent. In addition, insufficient evidence is available to support an association between seasonal variations in vitamin D and testosterone levels in Koreans. Therefore, we aimed to investigate the association between vitamin D and testosterone levels, and between seasonal variations in these levels in Korean men.

Methods

This cross-sectional study included 1,559 men, aged 25–86 years, who underwent a medical examination. We measured serum 25-hydroxyvitamin D (25[OH]D) and total testosterone levels, and compared other laboratory test results and patient lifestyle characteristics. On the basis of sample collection time, we categorized patients into four seasons, and analyzed seasonal variability in 25(OH)D and total testosterone levels.

Results

The average participant age (±standard deviation) was 53.3±8.8 years, and the average serum 25(OH)D and total testosterone levels were 15.9±7.0 ng/mL and 5.1±1.6 ng/mL, respectively. In the analysis of variance (ANOVA) model, no significant association was found between 25(OH)D and testosterone levels (P=0.51). ANOVA of the average 25(OH)D levels in season-based groups revealed significant seasonal variations in 25(OH)D levels (P-value for trend <0.001). No significant association was found between seasonal variations in total testosterone levels (P=0.06). However, after adjustment for confounding variables, total testosterone and 25(OH)D showed significant seasonal variability (P=0.007 and P<0.001, respectively).

Conclusion

We found no significant correlation between serum 25(OH)D and total testosterone levels in Korean men. Moreover, serum 25(OH)D and total testosterone levels showed significant seasonal variations.

Reproductive endocrinology of vitamin D

Vitamin D is a versatile hormone with several functions beyond its well-established role in maintenance of skeletal health and calcium homeostasis. The effects of vitamin D are mediated by the vitamin D receptor, which is expressed together with the vitamin D metabolizing enzymes in the reproductive tissues. The reproductive organs are therefore responsive to and able to metabolize vitamin D locally. The exact role remains to be clarified but several studies have suggested a link between vitamin D and production/release of reproductive hormones into circulation, which will be the main focus of this review. Current evidence is primarily based on small human association studies and rodent models. This highlights the need for randomized clinical trials, but also functional animal and human in vitro studies, and larger, prospective cohort studies are warranted. Given the high number of men and women suffering from reproductive problems and abnormal endocrinology research addressing the role of vitamin D in reproductive endocrinology may be of clinical importance.

The role of vitamin D in male fertility: A focus on the testis

In the last decade, vitamin D has emerged as a pleiotropic molecule with a multitude of autocrine, paracrine and endocrine functions, mediated by classical genomic as well as non-classical non-genomic actions, on multiple target organs and systems. The expression of vitamin D receptor and vitamin D metabolizing enzymes in male reproductive system, particularly in the testis, suggests the occurrence of vitamin D synthesis and regulation as well as function in the testis. The role of vitamin D in the modulation of testis functions, including hormone production and spermatogenesis, has been investigated in animals and humans. Experimental studies support a beneficial effect of vitamin D on male fertility, by modulating hormone production through genomic and non-genomic actions, and, particularly, by improving semen quality essentially through non-genomic actions. However, clinical studies in humans are controversial. Indeed, vitamin D seems to contribute to the modulation of the bioavailable rather than total testosterone. Moreover, although an increased prevalence or risk for testosterone deficiency was reported in men with vitamin D deficiency in observational studies, the majority of interventional studies demonstrated the lack of effect of vitamin D supplementation on circulating levels of testosterone. The most consistent effect of vitamin D was reported on semen quality. Indeed, vitamin D was shown to be positively associated to sperm motility, and to exert direct actions on spermatozoa, including non-genomic driven modulation of intracellular calcium homeostasis and activation of molecular pathways involved in sperm motility, capacitation and acrosome reaction. The current review provides a summary of current knowledge on the role of vitamin D in male fertility, by reporting clinical and experimental studies in humans and animals addressing the relationship between vitamin D and testis function.

The role of vitamin D supplementation on erectile function

In the last few years growing evidence highlighted vitamin D (VD) deficiency is one of the several dynamics that associates with increased atherosclerotic cardiovascular (ASCV) diseases. ASCV diseases and erectile dysfunction (ED) share common risk factors such as diabetes mellitus, hypertension, smoking, hyperlipidemia, and a sedentary lifestyle. The aim of this review was to summarize current progress in VD research by focusing effect of low VD level on different body systems and erectile function. Here we examine research linking VD deficiency and ED and discuss how VD influences ED and its classic risk factors that also associate to increased ED risk. We also summarize research indicating that VD associates with reduced risk of several nonvascular contributing factors for ED. Available literature demonstrates relatively high rates of low VD serum levels in ED patients. Based on the preclinical and clinical data available in the literature, to date, we infer that VD play a critical role in maintaining erectile function in humans. Nevertheless, this should also be tested through randomized controlled studies on the effect of VD supplementation with larger population.

Vitamin D treatment improves levels of sexual hormones, metabolic parameters and erectile function in middle-aged vitamin D deficient men

BACKGROUND

The associations between serum vitamin D (VD), serum testosterone (TT) and metabolic syndrome are complex and with limited published research, particularly on the effects of VD treatment on sexual hormones, erectile function and the metabolic syndrome.

OBJECTIVES

This study assessed whether a monthly high dose VD treatment for 12 months in VD deficient middle-aged men was associated with: changes in levels of sexual hormones, improvement of diabetes control and metabolic syndrome components, better erectile function [International Index of Erectile Function (IIEF)-5 questionnaire]; and changes in a prostate marker.

MATERIALS AND METHODS

Descriptive research of a prospective study, conducted between October 2014 and September 2015, 102 male patients ≥35 [(±SD: 53.2 ± 10.5), (range 35-64)] years with deficient serum VD level (<30 ng/mL) were included in the study. Participants were followed up for one year, with monitoring at 3-, 6-, 9- and 12-months. At the initial baseline visit, a complete medical examination was conducted, and blood was drawn for laboratory tests for above biochemical and hormonal variables under examination. Participants received an initial VD (Ergocalciferol; oral solution 600 000 IU/1.5 ml), and followed a VD treatment regime thereafter. At the four follow up visits (3, 6, 9 and 12 months), blood was collected, and patients' erectile function was evaluated by IIEF-5 questionnaire.

MAIN OUTCOME MEASURES

During the follow up visits, all the biochemical and hormonal (TT, estradiol and luteinizing hormones, HbA1c, serum lipids profile) were assessed, and patients' erectile function was evaluated by IIEF-5 questionnaire.

RESULTS

Patients' mean age was 53.2 ± 10.4 years. Serum VD exhibited significant increments (p <0.001) from baseline (15.16 ± 4.64 ng/mL), to 3 (31.90 ± 15.99 ng/mL), 6 (37.23 ± 12.42 ng/mL), 9 (44.88 ± 14.49 ng/mL) and 12 months (48.54 ± 11.62 ng/mL), and there was significant stepladder increases in both serum TT level (12.46 ± 3.30 to 15.99 ± 1.84 nmol/L) and erectile function scores (13.88 ± 3.96 to 20.25 ± 3.24) (p <0.001 for both). We also observed significant stepladder decreases in estradiol (87.90 ± 27.16 to 69.85 ± 14.80 pmol/L, p = 0.001), PTH (from 58.52 ± 28.99 to 38.33 ± 19.44 pg/mL, p <0.001) and HbA1c levels (7.41 ± 2.85 to 6.66 ± 1.67%, p = 0.001). Mean BMI significantly decreased from 33.91 ± 6.67 to 33.14 ± 6.35 kg/m² (p = 0.001); and PSA values significantly increased from 0.59 ± 0.30 to 0.82 ± 0.39 ng/mL (p <0.001) at the end of the 12 months' follow-up. There were no changes in LH levels.

CONCLUSION

This study demonstrated that VD treatment improves testosterone levels, metabolic syndrome and erectile function in middle-aged men. More randomized placebo-controlled interventional trials of VD treatment in patients with the metabolic syndrome and low TT could assist in uncovering the putative roles of VD.

Association of vitamin D status with semen quality and reproductive hormones in Iranian subfertile men

Although vitamin D deficiency is one of the most common health problems throughout the world, including Iran, conflicting information exists on the potential association between serum vitamin D levels and semen quality. This study intended to evaluate the association between serum vitamin D [25(OH) D3] with semen quality and hormones in Iranian subfertile men. We also compared mean vitamin D and hormone levels in normospermic men with oligoasthenoteratozoospermia (OAT) men. This cross-sectional study was conducted on 278 men who were referred to Royan Infertility Clinic (Tehran, Iran) from March to September 2014. The participants were categorized into two groups; of 186 normospermic and 92 OAT patients according to World Health Organization 2010 criteria. Each participant provided informed consent prior to launching research. Participants completed two general questionnaires of nutritional status. Blood and semen samples were obtained for assessment, and all data were adjusted for age, body mass index (BMI), and season. Vitamin D levels were classified according to Institute of Medicine guidelines. Vitamin D deficiency, insufficiency, and normal levels were observed in 8.6%, 43.6%, 47.8% of participants, respectively. No association was found between daily dietary intake of vitamin D and calcium with sperm parameters. Serum vitamin D was inversely correlated with PTH (p < 0.045). In normospermic men, serum vitamin D levels categorized were not correlated with semen parameters and reproductive hormones (FSH, LH, testosterone(T), and FT), whereas sperm motility showed a positive correlation with vitamin D categorized in OAT men (rs = 0.131, p = 0.028). In conclusion, there was a high incidence of deficiency and insufficiency 25(OH) D Levels (<20ng/ml) observed in Iranian men (52.2%). Moreover, our findings showed a correlation between vitamin D levels and sperm motility in OAT men, which requires further studies.

Vitamin D and chronic diseases: the current state of the art

The objective was to provide the current state of the art regarding the role of vitamin D in chronic diseases (osteoporosis, cancer, cardiovascular diseases, dementia, autism, type 1 and type 2 diabetes mellitus, male and female fertility). The document was drawn up by panelists that provided their contribution according to their own scientific expertise. Each scientific expert supplied a first draft manuscript on a specific aspect of the document's topic that was subjected to voting by all experts as "yes" (agreement with the content and/or wording) or "no" (disagreement). The adopted rule was that statements supported by ≥75 % of votes would be immediately accepted, while those with <25 % would be rejected outright. Others would be subjected to further discussion and subsequent voting, where ≥67 % support or, in an eventual third round, a majority of ≥50 % would be needed. This document finds that the current evidence support a role for vitamin D in bone health but not in other health conditions. However, subjects with vitamin D deficiency have been found to be at high risk of developing chronic diseases. Therefore, although at the present time there is not sufficient evidence to recommend vitamin D supplementation as treatment of chronic diseases, the treatment of vitamin D deficiency should be desiderable in order to reduce the risk of developing chronic diseases.

Vitamin D is associated with testosterone and hypogonadism in Chinese men: Results from a cross-sectional SPECT-China study

BACKGROUND

To date, no study has explored the association between androgen levels and 25-hydroxyvitamin D (25(OH)D) levels in Chinese men. We aimed to investigate the relationship between 25(OH)D levels and total and free testosterone (T), sex hormone binding globulin (SHBG), estradiol, and hypogonadism in Chinese men.

METHODS

Our data, which were based on the population, were collected from 16 sites in East China. There were 2,854 men enrolled in the study, with a mean (SD) age of 53.0 (13.5) years. Hypogonadism was defined as total T <11.3 nmol/L or free T <22.56 pmol/L. The 25(OH)D, follicle-stimulating hormone, luteinizing hormone, total T, estradiol and SHBG were measured using chemiluminescence and free T by enzyme-linked immune-sorbent assay. The associations between 25(OH)D and reproductive hormones and hypogonadism were analyzed using linear regression and binary logistic regression analyses, respectively.

RESULTS

A total of 713 (25.0 %) men had hypogonadism with significantly lower 25(OH)D levels but greater BMI and HOMA-IR. Using linear regression, after fully adjusting for age, residence area, economic status, smoking, BMI, HOMA-IR, diabetes and systolic pressure, 25(OH)D was associated with total T and estradiol (P < 0.05). In the logistic regression analyses, increased quartiles of 25(OH)D were associated with significantly decreased odds ratios of hypogonadism (P for trend <0.01). This association, which was considerably attenuated by BMI and HOMA-IR, persisted in the fully adjusted model (P for trend <0.01) in which for the lowest compared with the highest quartile of 25(OH)D, the odds ratio of hypogonadism was 1.50 (95 % CI, 1.14, 1.97).

CONCLUSIONS

A lower vitamin D level was associated with a higher prevalence of hypogonadism in Chinese men. This association might, in part, be explained by adiposity and insulin resistance and warrants additional investigation.