Vitamin D Deficiency Is Associated With Poor Ovarian Stimulation Outcome in PCOS but Not Unexplained Infertility

Effect of vitamin D on pregnancy in women with polycystic ovary syndrome: retrospective and prospective studies

RESEARCH QUESTION

Does vitamin D affect the pregnancy rate of patients with polycystic ovary syndrome (PCOS) receiving ovulation-induction therapy?

DESIGN

The retrospective study included 200 patients with PCOS and 200 healthy women. The prospective study included 160 patients with PCOS receiving vitamin D or placebo supplementation. Pregnancy rates were assessed after a maximum of three cycles of ovulation induction. Serum concentrations of 25-hydroxycalciferol [25-(OH)D3], LH, FSH, progesterone, oestradiol, testosterone and fasting insulin; LH/FSH ratio; and body mass index were evaluated.

RESULTS

In the retrospective study, patients with PCOS had lower 25-(OH)D3 concentrations than healthy women, pregnant patients with PCOS had higher 25-(OH)D3 concentrations than non-pregnant patients with PCOS (both P = 0.000), and the pregnancy rate was lower in the vitamin-D-deficient group compared with the non-vitamin-D-deficient group (P = 0.022). In the prospective study, compared with placebo supplementation, vitamin D supplementation increased the serum concentration of 25-(OH)D3 (P = 0.000), and reduced the LH/FSH ratio, and concentrations of LH and testosterone significantly (all P ≤ 0.049). After the intervention, it was found that the LH/FSH ratio, and concentrations of LH and testosterone were significantly lower in both groups compared with pre-intervention (P = 0.000). After ovulation induction, the pregnancy rate was higher in patients in the vitamin D supplementation group compared with the placebo supplementation group (P = 0.049).

CONCLUSIONS

Vitamin D deficiency is common in patients with PCOS, and vitamin-D-deficient patients with PCOS have lower pregnancy rates after ovulation induction compared with non-vitamin-D-deficient patients with PCOS. Vitamin D supplementation can improve the pregnancy rate and mitigate basic hormone disorders. Therefore, monitoring vitamin D supplementation and checking vitamin D concentrations before and during interventions are essential for patients with PCOS.

Association of rs4588 polymorphism in vitamin D binding protein gene with polycystic ovarian syndrome in Iranian women: a case-control study

OBJECTIVE

Vitamin D deficiency and variations in the vitamin D binding protein (VDBP) gene may play a role in the development of Polycystic ovary syndrome (PCOS). This study aims to investigate the association of the rs4588 polymorphism with PCOS in Iranian women, as well as its association with infertility and recurrent pregnancy loss (RPL) in these patients.

RESULTS

The analysis revealed statistically significant differences in the distributions of genotypes and alleles of the rs4588 polymorphism among the three groups (p < 0.0001). The AC genotype and A allele showed an association with an elevated risk of PCOS and infertility. In this study, no association was found between genotypes and alleles of the rs4588 polymorphism and the risk of RPL in women with PCOS. Subjects with the AA or AC genotype exhibited significantly higher levels of LDL compared to those with the CC genotype.

Systematic review and meta-analysis of pregnancy outcomes in women with polycystic ovary syndrome

Screening for polycystic ovary syndrome (PCOS) in antenatal care is inadequate, largely owing to the lack of clarity around whether PCOS is an independent risk factor for pregnancy complications. This systematic review and meta-analysis include 104 studies and 106,690 pregnancies in women with and without PCOS from inception until 13th July 2022. We report that women with PCOS are younger and have higher body mass index (BMI) around conception and have greater gestational weight gain. The odds of miscarriage, gestational diabetes mellitus, gestational hypertension, pre-eclampsia and cesarean section are higher in women with PCOS. The increased odds of adverse outcomes in PCOS remain significant when age and BMI are matched and when analyses are restricted to high-quality studies. This work informed the recommendations from the 2023 international evidence-based guideline for the assessment and management of polycystic ovary syndrome, emphasizing that PCOS status should be captured in all women who are planning to, or have recently become pregnant to facilitate prevention of adverse outcomes and improve pregnancy outcomes.

The impact of vitamin D treatment on pregnancy rate among endometriosis patients: a systematic review and meta-analysis

Background

Vitamin D supplementation is supposed to have an important role in the management of several endometriosis-related aspects, offering potential relief to affected individuals. Herein, the authors aim to evaluate the impact of vitamin D on pregnancy rates and clinical symptoms in women with endometriosis.

Methods

The authors extensively searched PubMed, Cochrane Library, EMBASE, Ovid MEDLINE, and CINAHL from their inception to 20 July 2023.

Results

Three randomized controlled trials involving 167 patients were included in this meta-analysis. The findings demonstrated that vitamin D supplementation exhibits efficacy in alleviating dysmenorrhea associated with endometriosis, as evidenced by a meta-analysis showing a significant reduction in dysmenorrhea (mean difference -1.41, 95% CI -2.61 to -0.22, P = 0.02). However, the impact on dyspareunia was inconclusive, with a non-significant mean difference of -0.2 (95% CI -1.62 to 1.22, P = 0.78). In contrast, dyschezia significantly decreased with vitamin D supplementation (mean difference -1.10, 95% CI -2.22 to 0.02, P = 0.05 However, the meta-analysis did not show a significant effect of vitamin D on chronic pelvic pain associated with endometriosis.

Conclusion

While antioxidant vitamin D supplementation demonstrates general effectiveness in alleviating endometriosis symptoms, such as dysmenorrhea, dyspareunia, and dyschezia, the existing literature lacks direct investigations into the specific impact of vitamin D on enhancing pregnancy rates among endometriosis patients. This observation prompts various hypotheses, suggesting that the positive effects of vitamin D supplementation on endometriosis-related symptoms may indirectly contribute to improved pregnancy outcomes and enhanced fertility.

Causal association between low vitamin D and polycystic ovary syndrome: a bidirectional mendelian randomization study

BACKGROUND

Recent studies have revealed the correlation between serum vitamin D (VD) level and polycystic ovary syndrome (PCOS), but the causality and specific mechanisms remain uncertain.

OBJECTIVE

We aimed to investigate the cause-effect relationship between serum VD and PCOS, and the role of testosterone in the related pathological mechanisms.

METHODS

We assessed the causality between serum VD and PCOS by using genome-wide association studies (GWAS) data in a bidirectional two-sample Mendelian randomization (TS-MR) analysis. Subsequently, a MR mediation analysis was conducted to examine the mediating action of testosterone in the causality between serum VD and PCOS. Ultimately, we integrated GWAS data with cis-expression quantitative loci (cis-eQTLs) data for gene annotation, and used the potentially related genes for functional enrichment analysis to assess the involvement of testosterone and the potential mechanisms.

RESULTS

TS-MR analysis showed that individuals with lower level of serum VD were more likely to develop PCOS (OR = 0.750, 95% CI: 0.587-0.959, P = 0.022). MR mediation analysis uncovered indirect causal effect of serum VD level on the risk of PCOS via testosterone (OR = 0.983, 95% CI: 0.968-0.998, P = 0.025). Functional enrichment analysis showed that several pathways may be involved in the VD-testosterone-PCOS axis, such as steroid hormone biosynthesis and autophagy process.

CONCLUSION

Our findings suggest that genetically predicted lower serum VD level may cause a higher risk of developing PCOS, which may be mediated by increased testosterone production.

Effect of vitamin D in addition to letrozole on the ovulation rate of women with polycystic ovary syndrome: protocol of a multicentre randomised double-blind controlled trial

INTRODUCTION

Low vitamin D status is prevalent among women with polycystic ovary syndrome (PCOS). The objective of the study is to assess the effect of vitamin D supplementation on (1) the ovulation rate to letrozole and (2) other reproductive, endocrine and metabolic outcomes after 1 year of supplementation in women with PCOS.

METHODS AND ANALYSIS

This is a multicentre, randomised, double-blind, controlled clinical trial. A total of 220 anovulatory women with PCOS diagnosed by the Rotterdam criteria will be recruited. They will be randomly assigned to either the (1) vitamin D supplementation group or (2) placebo group. Those in the vitamin D group will take oral Vitamin D3 50 000 IU/week for 4 weeks, followed by 50 000 IU once every 2 weeks for 52 weeks. Those who remain anovulatory after 6 months will be treated with a 6-month course of letrozole (2.5 mg to 7.5 mg for 5 days per cycle titrated according to response) for ovulation induction. The primary outcome is the ovulation rate. All statistical analyses will be performed using intention-to-treat and per protocol analyses.

ETHICS AND DISSEMINATION

Ethics approval was sought from the Institutional Review Board of the participating units. All participants will provide written informed consent before joining the study. The results of the study will be submitted to scientific conferences and peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04650880.

Vitamin D and its role in gynecology: emerging importance of checking vitamin D status in certain gynecological entities

Among non-bone effects of vitamin D, the three main chronological stages in gynecology ‒ menarche, reproductive stage and menopause/postmenopause - are possibly impacted by vitamin D deficiency. A large amount of emerging data show that vitamin D is a confounding factor in these parameters. Gynecology stays at the crossroads with endocrinology and, in the light of the rising knowledge about the involvement of vitamin D in many gynecological disorders, it is worth to investigate the exact role of vitamin D in this area. Especially since vitamin D is easy to substitute in case of deficiency. Authors present some emerging data on the role of vitamin D in gynecology, suggesting when it is necessary to check vitamin D status to intervene with vitamin D supplementation and raising gynecologists' awareness of the need for further clinical studies.

PCOS and vitamin D: a clinical appraisal

PURPOSE

Polycystic ovary syndrome (PCOS) is the most common endocrine-reproductive disease linked not just to infertility but also to serious comorbidities. There is a reported association between low vitamin D levels and multiple health conditions including PCOS. This narrative review aims to analyze the role of vitamin D in PCOS development, use of the vitamin D in the treatment of PCOS, and the molecular basis of these observations.

METHODS

A Medline and PubMed research was performed, during the years 1990-2023, using a combination of keywords on such topic. According to the author's evaluation and target, papers were identified and included for a narrative review.

RESULTS

There are associations between lower levels of vitamin D and PCOS, as well as with insulin resistance, metabolic syndrome, hyperandrogenemia, metabolic and endocrine disorders as well as the onset of oxidative stress and pro-inflammatory milieu, in PCOS women.

CONCLUSION

Vitamin D has a role in pathologic changes linked to PCOS. Molecular and clinical investigations which give new information about the role of vitamin D in the development of PCOS and related endocrine and metabolic disturbance are further needed.

Molecular Mechanisms in the Etiology of Polycystic Ovary Syndrome (PCOS): A Multifaceted Hypothesis Towards the Disease with Potential Therapeutics

Among the premenopausal women, Polycystic Ovary Syndrome (PCOS) is the most prevalent endocrinopathy affecting the reproductive system and metabolic rhythms leading to disrupted menstrual cycle. Being heterogeneous in nature it is characterized by complex symptomology of oligomennorhoea, excess of androgens triggering masculine phenotypic appearance and/or multiple follicular ovaries. The etiology of this complex disorder remains somewhat doubtful and the researchers hypothesize multisystem links in the pathogenesis of this disease. In this review, we attempt to present several hypotheses that tend to contribute to the etiology of PCOS. Metabolic inflexibility, aberrant pattern of gonadotropin signaling along with the evolutionary, genetic and environmental factors have been discussed. Considered a lifelong endocrinological implication, no universal treatment is available for PCOS so far however; multiple drug therapy is often advised along with simple life style intervention is mainly advised to manage its cardinal symptoms. Here we aimed to present a summarized view of pathophysiological links of PCOS with potential therapeutic strategies.

Seasonal Serum 25(OH) Vitamin D Level and Reproductive or Immune Markers in Reproductive-Aged Women with Infertility: A Cross-Sectional Observational Study in East Japan

Several studies have reported that vitamin D may modify human reproductive functions; however, the results are conflicting. We aimed to comprehensively evaluate serum vitamin D levels and examine the relationship between serum vitamin D levels and ovarian reserve markers, and immune markers of implantation, in reproductive-aged Japanese women with infertility.in reproductive-aged women with infertility. This cross-sectional, single-center study included reproductive-aged women who underwent preconception screening for fertility. Serum vitamin D levels and reproductive and immune markers were measured. Standard and advanced statistical techniques were used. We observed a statistically significant difference in the seasonal and monthly 25(OH) vitamin D levels; the 25(OH) vitamin D level during winter was the lowest among all seasons. However, there was no linear correlation between 25(OH) vitamin D levels and ovarian reserve markers, such as follicle-stimulating hormone and anti-Müllerian hormone, or the Th1/Th2 cell ratio, which is used as an implantation-related immunological marker. In this large-scale study, we evaluated the serum 25(OH) vitamin D concentration in reproductive-aged women with infertility in Japan; however, there was no association between reproductive function and vitamin D levels.

Evidence-based guideline: unexplained infertility†

STUDY QUESTION

What is the recommended management for couples presenting with unexplained infertility (UI), based on the best available evidence in the literature?

SUMMARY ANSWER

The evidence-based guideline on UI makes 52 recommendations on the definition, diagnosis, and treatment of UI.

WHAT IS KNOWN ALREADY

UI is diagnosed in the absence of any abnormalities of the female and male reproductive systems after 'standard' investigations. However, a consensual standardization of the diagnostic work-up is still lacking. The management of UI is traditionally empirical. The efficacy, safety, costs, and risks of treatment options have not been subjected to robust evaluation.

STUDY DESIGN, SIZE, DURATION

The guideline was developed according to the structured methodology for ESHRE guidelines. Following formulation of key questions by a group of experts, literature searches, and assessments were undertaken. Papers written in English and published up to 24 October 2022 were evaluated.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Based on the available evidence, recommendations were formulated and discussed until consensus was reached within the guideline development group (GDG). Following stakeholder review of an initial draft, the final version was approved by the GDG and the ESHRE Executive Committee.

MAIN RESULTS AND THE ROLE OF CHANCE

This guideline aims to help clinicians provide the best care for couples with UI. As UI is a diagnosis of exclusion, the guideline outlined the basic diagnostic procedures that couples should/could undergo during an infertility work-up, and explored the need for additional tests. The first-line treatment for couples with UI was deemed to be IUI in combination with ovarian stimulation. The place of additional and alternative options for treatment of UI was also evaluated. The GDG made 52 recommendations on diagnosis and treatment for couples with UI. The GDG formulated 40 evidence-based recommendations-of which 29 were formulated as strong recommendations and 11 as weak-10 good practice points and two research only recommendations. Of the evidence-based recommendations, none were supported by high-quality evidence, one by moderate-quality evidence, nine by low-quality evidence, and 31 by very low-quality evidence. To support future research in UI, a list of research recommendations was provided.

LIMITATIONS, REASONS FOR CAUTION

Most additional diagnostic tests and interventions in couples with UI have not been subjected to robust evaluation. For a large proportion of these tests and treatments, evidence was very limited and of very low quality. More evidence is required, and the results of future studies may result in the current recommendations being revised.

WIDER IMPLICATIONS OF THE FINDINGS

The guideline provides clinicians with clear advice on best practice in the care of couples with UI, based on the best evidence currently available. In addition, a list of research recommendations is provided to stimulate further studies in the field. The full guideline and a patient leaflet are available in www.eshre.eu/guideline/UI.

STUDY FUNDING/COMPETING INTEREST(S)

The guideline was developed by ESHRE, who funded the guideline meetings, literature searches, and dissemination of the guideline in collaboration with the Monash University led Australian NHMRC Centre of Research Excellence in Women's Health in Reproductive Life (CREWHIRL). The guideline group members did not receive any financial incentives; all work was provided voluntarily. D.R. reports honoraria from IBSA and Novo Nordisk. B.A. reports speakers' fees from Merck, Gedeon Richter, Organon and Intas Pharma; is part of the advisory board for Organon Turkey and president of the Turkish Society of Reproductive Medicine. S.B. reports speakers' fees from Merck, Organon, Ferring, the Ostetric and Gynaecological Society of Singapore and the Taiwanese Society for Reproductive Medicine; editor and contributing author, Reproductive Medicine for the MRCOG, Cambridge University Press; is part of the METAFOR and CAPE trials data monitoring committee. E.B. reports research grants from Roche diagnostics, Gedeon Richter and IBSA; speaker's fees from Merck, Ferring, MSD, Roche Diagnostics, Gedeon Richter, IBSA; E.B. is also a part of an Advisory Board of Ferring Pharmaceuticals, MSD, Roche Diagnostics, IBSA, Merck, Abbott and Gedeon Richter. M.M. reports consulting fees from Mojo Fertility Ltd. R.J.N. reports research grant from Australian National Health and Medical Research Council (NHMRC); consulting fees from Flinders Fertility Adelaide, VinMec Hospital Hanoi Vietnam; speaker's fees from Merck Australia, Cadilla Pharma India, Ferring Australia; chair clinical advisory committee Westmead Fertility and research institute MyDuc Hospital Vietnam. T.P. is a part of the Research Council of Finland and reports research grants from Roche Diagnostics, Novo Nordics and Sigrid Juselius foundation; consulting fees from Roche Diagnostics and organon; speaker's fees from Gedeon Richter, Roche, Exeltis, Organon, Ferring and Korento patient organization; is a part of NFOG, AE-PCOS society and several Finnish associations. S.S.R. reports research grants from Roche Diagnostics, Organon, Theramex; consulting fees from Ferring Pharmaceuticals, MSD and Organon; speaker's fees from Ferring Pharmaceuticals, MSD/Organon, Besins, Theramex, Gedeon Richter; travel support from Gedeon Richter; S.S.R. is part of the Data Safety Monitoring Board of TTRANSPORT and deputy of the ESHRE Special Interest Group on Safety and Quality in ART; stock or stock options from IVI Lisboa, Clínica de Reprodução assistida Lda; equipment/medical writing/gifts from Roche Diagnostics and Ferring Pharmaceuticals. S.K.S. reports speakers' fees from Merck, Ferring, MSD, Pharmasure. HRV reports consulting and travel fees from Ferring Pharmaceuticals. The other authors have nothing to disclose.

DISCLAIMER

This guideline represents the views of ESHRE, which were achieved after careful consideration of the scientific evidence available at the time of preparation. In the absence of scientific evidence on certain aspects, a consensus between the relevant ESHRE stakeholders has been obtained. Adherence to these clinical practice guidelines does not guarantee a successful or specific outcome, nor does it establish a standard of care. Clinical practice guidelines do not replace the need for application of clinical judgment to each individual presentation, nor variations based on locality and facility type. ESHRE makes no warranty, express or implied, regarding the clinical practice guidelines and specifically excludes any warranties of merchantability and fitness for a particular use or purpose. (Full disclaimer available at www.eshre.eu/guidelines.).

The role of serum vitamin D in patients with normal ovarian reserve undergoing the first IVF/ICSI cycle

Background

The debate over the impact of vitamin D in assisted reproduction continues. The purpose of our study was to assess embryo quality and pregnancy outcomes among groups with different levels of vitamin D after the first in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycle in patients with normal ovarian reserve (NOR).

Methods

Patients in this retrospective cohort study were divided into three groups: severe vitamin D deficiency group (25OH-D < 10 ng/ml), vitamin D deficiency group (10 ng/ml ≤ 25OH-D < 20 ng/ml), and non-vitamin D deficiency group (25OH-D ≥ 20 ng/ml). The primary outcome was clinical pregnancy, while the secondary outcomes were mature oocytes, oocyte fertilization, available cleavage embryos, available blastocysts, biochemical pregnancy, early abortion, and embryo implantation. A modified Poisson regression model and multiple linear regression analysis were conducted for the multivariate analysis.

Results

264 NOR patients undergoing the first IVF/ICSI cycles were included. For the primary outcome, there was no significant difference in clinical pregnancy between the severe vitamin D deficiency group and the other two groups (vitamin D deficiency group: adjusted RR = 1.026; 0.780 - 1.350; P = 0.854; non-vitamin D deficiency group: adjusted RR = 1.092; 0.743 - 1.605; P = 0.652). For all secondary outcomes, no significant differences were observed among the severe vitamin D deficiency, vitamin D deficiency, and non-vitamin D deficiency groups (P > 0.05). Exploratory subgroup analyses concerning the season of embryo transfer, phase of embryo transferred, and endometrial thickness, as well as the sensitivity analysis using logistic regression models for the primary outcome, revealed comparable clinical pregnancy rates among the groups (P > 0.05). Subgroup analysis concerning ovarian stimulation protocol indicated that in the subgroup of gonadotrophin-releasing hormone (GnRH) antagonist protocol, the clinical pregnancy rate of the non-vitamin D deficiency group was significantly higher than that of the other two groups (P < 0.05).

Conclusion

Serum vitamin D level was not associated with embryo quality and pregnancy outcomes for patients with NOR. Further studies with greater sample sizes and a longer follow-up period are needed to elucidate the relationships between vitamin D levels and IVF outcomes.

Preconception Vitamin D Level and In Vitro Fertilization: Pregnancy Outcome

OBJECTIVE

Vitamin D deficiency impairs female fertility and the success of in vitro fertilization (IVF). The recommended serum 25-hydroxyvitamin D (25(OH)D) level in IVF-conceived pregnancies is still debated. We aimed to explore the relationship of the preconception serum 25(OH)D level with pregnancy outcome following IVF treatment. We also explored the utility of the currently recommended serum 25(OH)D cutoff of ≥50 nmol/L for women undergoing IVF therapy.

METHODS

Retrospective cohort of women who had undergone IVF therapy. Of the women who started IVF therapy (n = 354), 218 completed the study. They were divided into 2 groups: (1) women who achieved a successful pregnancy (pregnant group, n = 160) and (2) those who did not achieve a successful pregnancy (nonpregnant group, n = 58). Preconception serum samples were analyzed for reproductive hormones, fasting glucose, insulin, and 25(OH)D levels.

RESULTS

Overall, the median (interquartile range) age, body mass index, and hemoglobin A1c level were 32 (6) years, 25.7 (7.4) kg/m², and 5.2% (0.6%), respectively. The 25(OH)D level was significantly higher at preconception in the pregnant group (56.4 [21.4] vs 47.9 [29.16] for nonpregnant, P = .001). The preconception 25(OH)D level was a significant predictor of IVF outcome (B = 0.04; 95% CI, 1.01-1.06; P = .001), with greater IVF success associated with a serum 25(OH)D level of ≥50 nmol/L (odds ratio, 0.46; P = .01).

CONCLUSION

Preconception 25(OH)D sufficiency (≥50 nmol/L) is associated with successful pregnancy outcome following IVF therapy.

The Application of Complementary and Alternative Medicine in Polycystic Ovary Syndrome Infertility

Polycystic ovary syndrome (PCOS) is a lifelong reproductive endocrine disease, which is the most common cause of anovular infertility. Modern medicine mainly treats infertile patients with PCOS by improving living habits, ovulation induction therapy, and assisted reproductive technology (ART), but the effect is not satisfied. Complementary alternative medicine (CAM) has conspicuous advantages in the treatment of PCOS infertility due to its good clinical efficacy, wide mechanism of action, and no obvious adverse reactions, but its safety and effectiveness in the treatment of PCOS infertility have not been proved. Based on the existing clinical and experimental studies, this paper looks for the therapeutic effect and the mechanism behind it, and explores the safety and effectiveness of its treatment in PCOS infertility, in order to provide reference for future clinical treatment and experimental research.

The role of sleep in PCOS: what we know and what to consider in the future

INTRODUCTION

Sleep disturbance and clinical sleep conditions disrupt endocrine signals, energy expenditure and nutritional intake. Women with polycystic ovary syndrome (PCOS) are at higher risk of sleep disturbances and clinical conditions. It is possible that sleep may contribute to the exacerbation of PCOS. This review aims to explore the relationship between sleep and chronic disease, particularly in women with PCOS.

AREAS COVERED

This review narratively explores what sleep is, how to measure sleep and the possible mechanisms that support the link between sleep in adipose tissue deposition, insulin resistance and the presentation of PCOS.

EXPERT OPINION

Research shows that disturbed sleep and clinical sleep conditions disrupt energy expenditure. This may increase adipose tissue deposition and exacerbate insulin resistance which are known to worsen the presentation of PCOS. Further, sleep disturbance in women with PCOS may ameliorate any positive lifestyle changes made after diagnosis. Cognitive behavioural therapy interventions for sleep are a successful strategy for the management of sleep disturbances in the general population. However, such interventions are yet to be trialled in women with PCOS. Given the proposed implications, interventions to improve sleep could provide additional support for women with PCOS to successfully implement lifestyle strategies and should be further investigated.

Effects of vitamin D supplementation on ovarian reserve markers in infertile women with diminished ovarian reserve

The purpose of this study was to evaluate the effects of vitamin D supplementation on ovarian reserve markers, including serum anti-Mullerian hormone (AMH) level, follicle-stimulating hormone (FSH) level, and antral follicle count (AFC), in infertile women with diminished ovarian reserve and vitamin D deficiency.A prospective, nonrandomized, cross-sectional study was conducted. Women aged 18 to 41 years who were unable to become pregnant after 12 months of sexual intercourse and had normal tubal patency, partners with normal semen analysis, diminished ovarian reserve, and 25-hydroxyvitamin D [25(OH)D] deficiency were included. Eligible patients' AFC and serum levels of AMH, FSH, 25(OH)D, 1,25-dihydroxyvitamin D [1,25(OH)D], calcium, phosphate, alkaline phosphatase, and parathormone were assessed before and after administration of 300,000 IU of vitamin D ampules. Changes in the parameter values after vitamin D supplementation were compared with the initial levels.The study was conducted in 62 of the 142 participants. The AFC and AMH, 25(OH)D, 1,25(OH)D, phosphate (P < .01), and calcium levels (P < .05) were statistically significantly increased after vitamin D supplementation. Statistically significant decreases in FSH (P < .01) and alkaline phosphatase levels (P < .05) were observed after vitamin D supplementation. No statistically significant correlations were found between 25(OH)D level and AFC, 1,25(OH)D level, AMH level, and FSH level before and after supplementation (P > .05).As improvements in the ovarian reserve markers were obtained with vitamin D supplementation, vitamin D might be considered as a fertility treatment for patients with diminished ovarian reserve and vitamin D deficiency.

Low Serum 25-Hydroxyvitamin D Levels Are Associated With Hyperandrogenemia in Polycystic Ovary Syndrome: A Cross-Sectional Study

BACKGROUND

Increasing evidence suggests a link between vitamin D and polycystic ovary syndrome (PCOS). However, whether vitamin D is related to hyperandrogenemia in PCOS is still inconclusive. The aim of our study is to elucidate the relationship between vitamin D and hyperandrogenemia in women with PCOS in China.

METHODS

This is a cross-sectional study including 625 Chinese women with PCOS and 217 controls from January 2016 to June 2020. The anthropometric and biochemical parameters related to 25(OH)D, sex steroids, glucose and lipid profiles were measured.

RESULTS

Serum 25(OH)D levels were lower in women with PCOS than controls (33.99 ± 15.05 vs 36.58 ± 16.49 nmol/L, P = 0.034), especially lower in hyperandrogenic women with PCOS (32.79 ± 14.24 vs 36.21 ± 16.27 nmol/L, P = 0.007). Higher 25(OH)D levels were independently associated with lower risks of hyperandrogenemia after adjusting demographic, metabolic and hormonal confounders (OR = 0.982, 95% CI: 0.969 - 0.995, P = 0.006). Consistent results were observed in subgroup analyses. Among PCOS women with vitamin D deficiency, females with age ≥ 26 years had lower risks of hyperandrogenemia (OR = 0.611, 95% CI = 0.389 - 0.958, P = 0.032), while overweight patients had higher risks of hyperandrogenemia (OR = 2.202, 95% CI = 1.130 - 4.293, P = 0.020) after adjusting multiple confounders.

CONCLUSIONS

Our study reported lower vitamin D levels in Chinese women with PCOS, especially in those with hyperandrogenemia. An independent negative correlation between 25(OH)D and hyperandrogenemia was noted in PCOS. For PCOS women with vitamin D deficiency, females that have higher BMI with age < 26 years may be prioritized for hyperandrogenemia assessment.

Mechanisms Involved in the Relationship between Vitamin D and Insulin Resistance: Impact on Clinical Practice

Recent evidence has revealed anti-inflammatory properties of vitamin D as well as extra-skeletal activity. In this context, vitamin D seems to be involved in infections, autoimmune diseases, cardiometabolic diseases, and cancer development. In recent years, the relationship between vitamin D and insulin resistance has been a topic of growing interest. Low 25-hydroxyvitamin D (25(OH)D) levels appear to be associated with most of the insulin resistance disorders described to date. In fact, vitamin D deficiency may be one of the factors accelerating the development of insulin resistance. Vitamin D deficiency is a common problem in the population and may be associated with the pathogenesis of diseases related to insulin resistance, such as obesity, diabetes, metabolic syndrome (MS) and polycystic ovary syndrome (PCOS). An important question is the identification of 25(OH)D levels capable of generating an effect on insulin resistance, glucose metabolism and to decrease the risk of developing insulin resistance related disorders. The benefits of 25(OH)D supplementation/repletion on bone health are well known, and although there is a biological plausibility linking the status of vitamin D and insulin resistance supported by basic and clinical research findings, well-designed randomized clinical trials as well as basic research are necessary to know the molecular pathways involved in this association.

Associations of urine metals and metal mixtures during pregnancy with cord serum vitamin D Levels: A prospective cohort study with repeated measurements of maternal urinary metal concentrations

BACKGROUND

Vitamin D deficiency has been associated with the increased risk of many diseases, especially during early life. Exposure to some toxic metals may decrease vitamin D levels in adults and children in previous studies. However, less is known about the associations of maternal metals exposure during pregnancy with newborns' vitamin D status.

OBJECTIVE

We conducted a prospective cohort study to investigate the relationships between urine metals and metal mixtures during pregnancy and newborns' vitamin D status.

METHODS

Urine samples of 598 pregnant women were collected in each trimester and cord blood samples of newborns were collected at delivery. The concentrations of 20 metals in urine and 25-hydroxyvitamin D [25(OH)D] in cord serum were quantified. Generalized linear models were used to estimate the associations between individual metals and cord serum total 25(OH)D. We applied Bayesian Kernel Machine Regression (BKMR) to evaluate the mixture and interaction effects of urine metals.

RESULTS

In individual metals analyses, we reported that a double increase in urine vanadium (V), cobalt (Co), and thallium (Tl) throughout pregnancy was associated with a 9.91% [95% confidence interval (CI): -18.58%, -0.30%], 11.42% (95% CI: -17.73%, -4.63%), and 12.64% (95% CI: -21.44%, -2.86%) decrease in cord serum total 25(OH)D, respectively. Exposures to the three metals during the whole pregnancy were also correlated to increased odds for newborns' vitamin D deficiency (<20 ng/mL) [odds ratio (95% CI): 1.80 (1.05, 3.10) for V, 1.88 (1.25, 2.82) for Co, and 1.90 (1.07, 3.38) for Tl]. BKMR analyses revealed a negative influence of metal mixtures (V+Co+Tl) on neonatal vitamin D status, as well as potential synergism between V and Co and between V and Tl.

CONCLUSIONS

Our study provides evidence of negative impacts of maternal exposure to V, Co, and Tl during pregnancy on cord serum vitamin D levels at delivery. Potential synergism between V and Co and between V and Tl existed in their associations with cord serum total 25(OH)D.

Male vitamin D status and male factor infertility

OBJECTIVE

To determine the association between vitamin D levels in the male partner and fertility outcomes in couples with mild male factor infertility.

DESIGN

Secondary analysis of a randomized, controlled trial.

SETTING

Nine fertility centers in the United States.

PATIENT(S)

Men (n = 154) with sperm concentration between 5 and 15 million/mL, motility ≤40%, or normal morphology ≤4% were eligible. Female partners were ovulatory, ≤40 years old, and had documented tubal patency.

INTERVENTION(S)

Men provided semen and blood at baseline for semen analysis and 25-hydroxyvitamin D (25(OH)D) levels. They were randomly assigned to receive a vitamin formulation including vitamin D 2,000 IU daily or placebo for up to 6 months. Couples attempted to conceive naturally during the first 3 months and with clomiphene citrate with intrauterine insemination of the female partner in months 4 through 6.

MAIN OUTCOME MEASURE(S)

Primary: sperm concentration, motility, morphology, and DNA fragmentation at baseline. Secondary: cumulative pregnancy, miscarriage, and live birth rates.

RESULT(S)

Semen parameters and sperm DNA fragmentation were not statistically significantly different between men with vitamin D deficiency and men with 25(OH)D levels ≥20 ng/mL. In addition, clinical pregnancy and live birth rates were similar. Male 25(OH)D level <20 ng/mL was associated with a higher rate of pregnancy loss (adjusted odds ratio 9.0; 95% confidence interval 1.3 to 61.3).

CONCLUSION(S)

Vitamin D deficiency in the male partner did not significantly impact semen parameters or treatment outcomes. Further study is warranted to better characterize the rate of miscarriage in couples with male vitamin D deficiency.

Assessing the impact of an educational intervention program based on the theory of planned behavior on the nutritional behaviors of adolescents and young adults with PCOS in Iran: a field trial study

BACKGROUND

Polycystic ovary syndrome is the most common endocrine disorder among adolescents and adults. Given the importance of healthy nutritional behaviors in management of this disease, the present study was conducted to determine the impact of an educational intervention program based on the theory of planned behavior on the nutritional behaviors of adolescents and young adults with polycystic ovary syndrome.

METHODS

In this field trial study, 72 participants aged between 15 and 21 years old from four gynecology clinics in Shiraz, Iran, were assigned into the intervention and control groups. Educational intervention program was implemented based on the theory of planned behavior over 4 sessions during two weeks. The data collection tools were researcher-made questionnaires of demographic information, knowledge assessment, and assessment of theory of planned behavior constructs, as well as a questionnaire for assessing consumption of food groups, fast food, and snacks. The data were collected at two stages (once at baseline and once three months after the intervention), and then the changes in knowledge, attitude, subjective norms, the perceived behavioral control, behavioral intention, and nutritional behavior were analyzed using descriptive and inferential statistical methods (t-test, Chi-square, Mann- Whitney U, and Wilcoxon tests; as well as one- way ANOVA, repeated measures ANOVA, and ANCOVA, respectively).

RESULTS

Statistically significant increases were observed in the mean scores of knowledge, attitude, subjective norms, the perceived behavioral control, behavioral intention, and nutritional behavior in the intervention group by passing three months from the intervention compared to the scores before the intervention (P < 0.001). However, these differences were not statistically significant in the control group (P > 0.05). Moreover, the mean scores of knowledge, attitude, subjective norms, perceived behavioral control, behavioral intention, and nutritional behavior had no statistically significant difference before the intervention between the two groups; however, this was statistically significant by passing three months from the intervention (P < 0.001).

CONCLUSION

Considering the effect of an educational intervention program based on the theory of planned behavior on creating healthy nutritional behaviors in adolescents and young adults with polycystic ovary syndrome, it is recommended to use it in order to improve the nutritional health of them.

TRIAL REGISTRATION

IRCT, IRCT20160224026756N6. Registered 18 Aug 2018, https://en.irct.ir/user/trial/32693/view.

Development of a LC-MS/MS method to measure serum 3-sulfate and 3-glucuronide 25-hydroxyvitamin D3 metabolites; comparisons to unconjugated 25OHD in pregnancy and polycystic ovary syndrome

Vitamin D status is routinely assessed by measuring circulating concentrations of 25-hydroxyvitamin D (25OHD2 or 25OHD3). However as deconjugation is not routinely incorporated into sample treatment prior to analysis, conjugated forms of 25OHD (particularly the more abundant 25OHD3) are often not considered in determining serum concentrations of total 25OHD. Two major circulating conjugated forms of 25OHD3 are 25-hydroxyvitamin D3-3-sulfate (25OHD3-S) and 25-hydroxyvitamin D3-3-glucuronide (25OHD3-G). Incorporating these two conjugated metabolites into the measurement of vitamin D status could improve our understanding of vitamin D status in health, particularly if there are changes in sulfation and glucuronidation activities. The aim of this study was to develop a liquid chromatography tandem-mass spectrometry (LC-MS/MS) targeted method for measurement of 25OHD3-S and 25OHD3-G in serum to enable comparisons with circulating levels of the free 25OHD3 form. We developed and validated a new LC-MS/MS method that measured both 25OHD3-S and 25OHD3-G following a solid phase extraction sample preparation method. Partial separation of analytes by LC, and the separation of analytes by the optimized multiple reaction monitoring transitions enabled the quantitation of both 25OHD3-S and 25OHD3-G in the single method. Serum concentrations of 25OHD3-S (24.7 ± 11.8 ng/mL) and 25OHD3-G (2.4 ± 1.2 ng/mL) were shown to be a significant proportion of circulating vitamin D metabolites in healthy donor serums. These levels of 25OHD3-S and 25OHD3-G closely associated with 25OHD3 concentrations, r = 0.728, p = 0.001 and r = 0.632, p = 0.006 respectively. However in serum from pregnant women and non-pregnant women with polycystic ovary syndrome (PCOS) significant differences in the ratios between conjugated and free 25OHD3 were observed between pregnancy groups (25OHD3/25OHD3-S and 25OHD3/25OHD3-G p < 0.001), and between healthy and PCOS subjects (25OHD3/25OHD3-G p < 0.050). Development of this novel high-throughput LC-MS/MS method indicates that 25OHD3-S and 25OHD3-G are substantial components of circulating vitamin D metabolites. The concentrations of these metabolites relative to conventional 25OHD3 may vary in different physiological and pathophysiological settings, and may therefore play an unrecognized but important role in the actions of vitamin D.

Effects of Vitamin D Supplementation on Surrogate Markers of Fertility in PCOS Women: A Randomized Controlled Trial

Vitamin D (VD) might play an important role in polycystic ovary syndrome (PCOS) and female fertility. However, evidence from randomized controlled trials (RCT) is sparse. We examined VD effects on anti-Müllerian hormone (AMH) and other endocrine markers in PCOS and non-PCOS women. This is a post hoc analysis of a single-center, double-blind RCT conducted between December 2011 and October 2017 at the endocrine outpatient clinic at the Medical University of Graz, Austria. We included 180 PCOS women and 150 non-PCOS women with serum 25-hydroxyvitamin D (25(OH)D) concentrations <75 nmol/L in the trial. We randomized subjects to receive 20,000 IU of VD3/week (119 PCOS, 99 non-PCOS women) or placebo (61 PCOS, 51 non-PCOS women) for 24 weeks. Outcome measures were AMH, follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol, dehydroepiandrosterone sulfate, and androstenedione. In PCOS women, we observed a significant treatment effect on FSH (mean treatment effect 0.94, 95% confidence interval [CI] 0.087 to 1.799, p = 0.031) and LH/FSH ratio (mean treatment effect −0.335, 95% CI −0.621 to 0.050, p = 0.022), whereas no significant effect was observed in non-PCOS women. In PCOS women, VD treatment for 24 weeks had a significant effect on FSH and LH/FSH ratio but no effect on AMH levels.

Infertility management in women with polycystic ovary syndrome: a review

Polycystic ovary syndrome is the most common endocrine disorder in women and a major cause of anovulatory infertility. Various medical options are used, alone or in combination, to treat subfertility associated with polycystic ovary syndrome. This narrative review was conducted to provide an update and summarize the available evidence on the management of polycystic ovary syndrome related infertility. A wide literature search was performed and preferably randomized controlled trials and systematic reviews were included. Management is often centered on lifestyle changes. Pharmacological ovulation induction is the next step, with recommended use of letrozole, clomiphene citrate or gonadotropins. When it fails, assisted reproductive technologies or laparoscopic ovarian drilling are frequently advised. Combination treatment with metformin is often recommended. More recent alternative and adjunctive treatments have been suggested, like inositol, vitamin D, bariatric surgery and acupuncture, but further research is needed for recommendation.

Gut Microbiota in Patients with Polycystic Ovary Syndrome: a Systematic Review

Polycystic ovary Syndrome (PCOS) is one of the most popular diseases that cause menstrual dysfunction and infertility in women. Recently, the relationships between the gastrointestinal microbiome and metabolic disorders such as obesity, type 2 diabetes and PCOS have been discovered. However, the association between the gut microbiome and PCOS symptoms has not been well established. We systematically reviewed existing studies comparing gut microbial composition in PCOS and healthy volunteers to explore evidence for this association. A systematic search was carried out in PubMed, Embase, Cochrane Library, and Web of Science from inception to May 26, 2020, for all original cross-sectional, cohort, or case-control studies comparing the fecal microbiomes of patients with PCOS with microbiomes of healthy volunteers (controls). The primary outcomes were differences in specific gut microbes between patients with PCOS and controls. The search identified 256 citations; 10 studies were included. The total population study of these articles consists of 611 participants (including PCOS group and healthy controls group). Among the included 10 studies, nine studies compared α-diversity, and six studies demonstrated that α-diversity has a significant reduction in PCOS patients. Seven of them reported that there was a significant difference of β-diversity composition between healthy controls groups and PCOS patients. The most common bacterial alterations in PCOS patients included Bacteroidaceae, Coprococcus, Bacteroides, Prevotella, Lactobacillus, Parabacteroides, Escherichia/Shigella, and Faecalibacterium prausnitzii. No consensus has emerged from existing human studies of PCOS and gut microbiome concerning which bacterial taxa are most relevant to it. In this systematic review, we identified specific bacteria associated with microbiomes of patients with PCOS vs controls. Higher level of evidence is needed to determine whether these microbes are a product or cause of PCOS.

Resistance to the Insulin and Elevated Level of Androgen: A Major Cause of Polycystic Ovary Syndrome

PCOS has a wide range of negative impacts on women's health and is one of the most frequent reproductive systemic endocrine disorders. PCOS has complex characteristics and symptom heterogeneity due to the several pathways that are involved in the infection and the absence of a comm14on cause. A recent study has shown that the main etiology and endocrine aspects of PCOS are the increased level of androgen, which is also known as "hyperandrogenemia (HA)" and secondly the "insulin resistance (IR)". The major underlying cause of the polycystic ovary is these two IR and HA, by initiating the disease and its severity or duration. As a consequence, study on Pathogenesis is crucial to understand the effect of "HA" and "IR" on the pathophysiology of numerous symptoms linked to PCOS. A deep understanding of the pattern of the growth in PCOS for HA and IR can help ameliorate the condition, along with adjustments in nutrition and life, as well as the discovery of new medicinal products. However, further research is required to clarify the mutual role of IR and HA on PCOS development.

Follicular and serum levels of vitamin D in women with unexplained infertility and their relationship with in vitro fertilization outcome: an observational pilot study

INTRODUCTION

Follicular and serum vitamin D are considered potential markers of the oocyte and embryos' quality and predictors of in vitro fertilization (IVF) outcomes.

METHODS

This retrospective cross-sectional study correlated vitamin D in sera and follicular fluid of women with unexplained infertility mutually and with IVF outcomes. ELISA was used for measuring vitamin D.

RESULTS

The results show positive correlation only between follicular and serum levels of vitamin D (Rho = 0.615, p = 0.025), and between follicular levels of vitamin D and the percentage of embryo fragmentation (Rho = 0.544; p = 0.036).

CONCLUSIONS

The results suggest that serum and follicular fluid vitamin D measurements could be complementary tools to the routine assessment of embryos.

Endometrial function in women with polycystic ovary syndrome: a comprehensive review

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common cause of anovulatory infertility. An endometrial component has been suggested to contribute to subfertility and poor reproductive outcomes in affected women.

OBJECTIVE AND RATIONALE

The aim of this review was to determine whether there is sufficient evidence to support that endometrial function is altered in women with PCOS, whether clinical features of PCOS affect the endometrium, and whether there are evidence-based interventions to improve endometrial dysfunction in PCOS women.

SEARCH METHODS

An extensive literature search was performed from 1970 up to July 2020 using PubMed and Web of Science without language restriction. The search included all titles and abstracts assessing a relationship between PCOS and endometrial function, the role played by clinical and biochemical/hormonal factors related to PCOS and endometrial function, and the potential interventions aimed to improve endometrial function in women with PCOS. All published papers were included if considered relevant. Studies having a specific topic/hypothesis regarding endometrial cancer/hyperplasia in women with PCOS were excluded from the analysis.

OUTCOMES

Experimental and clinical data suggest that the endometrium differs in women with PCOS when compared to healthy controls. Clinical characteristics related to the syndrome, alone and/or in combination, may contribute to dysregulation of endometrial expression of sex hormone receptors and co-receptors, increase endometrial insulin-resistance with impaired glucose transport and utilization, and result in chronic low-grade inflammation, immune dysfunction, altered uterine vascularity, abnormal endometrial gene expression and cellular abnormalities in women with PCOS. Among several interventions to improve endometrial function in women with PCOS, to date, only lifestyle modification, metformin and bariatric surgery have the highest scientific evidence for clinical benefit.

WIDER IMPLICATIONS

Endometrial dysfunction and abnormal trophoblast invasion and placentation in PCOS women can predispose to miscarriage and pregnancy complications. Thus, patients and their health care providers should advise about these risks. Although currently no intervention can be universally recommended to reverse endometrial dysfunction in PCOS women, lifestyle modifications and metformin may improve underlying endometrial dysfunction and pregnancy outcomes in obese and/or insulin resistant patients. Bariatric surgery has shown its efficacy in severely obese PCOS patients, but a careful evaluation of the benefit/risk ratio is warranted. Large scale randomized controlled clinical trials should address these possibilities.

Vitamin D supplementation prior to in vitro fertilisation in women with polycystic ovary syndrome: a protocol of a multicentre randomised, double-blind, placebo-controlled clinical trial

INTRODUCTION

Polycystic ovary syndrome (PCOS) is one of the leading causes of female infertility, affecting around 5% of women of childbearing age in China. Vitamin D insufficiency is common in women with PCOS and is associated with lower live birth rates. However, evidence regarding the effectiveness of vitamin D supplementation in women with PCOS is inconclusive. This multicentre randomised, double-blinded, placebo-controlled trial aims to evaluate the effectiveness of vitamin D supplementation prior to in vitro fertilisation (IVF) on the live birth rate in women with PCOS.

METHODS AND ANALYSIS

We plan to enrol women with PCOS scheduled for IVF. After informed consent, eligible participants will be randomised in a 1:1 ratio to receive oral capsules of 4000 IU vitamin D per day or placebo for around 12 weeks until the day of triggering. All IVF procedures will be carried out routinely in each centre. The primary outcome is live birth after the first embryo transfer. The primary analysis will be by intention-to-treat analysis. To demonstrate or refute that treatment with vitamin D results in a 10% higher live birth rate than treatment with placebo, we need to recruit 860 women (48% vs 38% difference, anticipating 10% loss to follow-up and non-compliance, significance level 0.05 and power 80%).

ETHICS AND DISSEMINATION

This study has been approved by the Ethics Committee in Women's Hospital of Zhejiang University on 2 March 2020 (reference number: IRB-20200035-R). All participants will provide written informed consent before randomisation. The results of the study will be submitted to scientific conferences and a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT04082650.

The association between anti-Müllerian hormone and vitamin 25(OH)D serum levels and polycystic ovarian syndrome in adolescent females

BACKGROUND

High anti-Müllerian hormone (AMH) levels and 25-hydroxyvitamin D [25(OH)D] deficiency have been associated with polycystic ovarian syndrome (PCOS) in adult women, and implicated in its pathogenesis. Herein we determined if the level of both AMH and 25(OH)D are altered in adolescent females with clinical features of PCOS.

METHODS

This is a cross-sectional study utilizing a retrospective chart review of 128 patients aged 12-20 referred to an academic adolescent gynecology and endocrinology clinic for an evaluation of suspected PCOS. Unadjusted comparisons of AMH and 25(OH)D distributions between subjects with and without PCOS were performed using the Wilcoxon Rank Sum test. Quantile regression was used to compare the median AMH and 25(OH)D between subject groups; adjusting for race, ethnicity, BMI, insurance type, age, and season when bloodwork was performed.

RESULTS

Seventy-four subjects were classified as having PCOS by meeting ≥2 of the three Rotterdam diagnostic criteria, and 47 subjects met only one Rotterdam diagnostic criteria, and were used as the comparative non-PCOS group. There were statistically significant unadjusted differences in median levels of AMH and 25(OH)D. In the adjusted analyses, median AMH was significantly higher in the PCOS group compared to the non-PCOS group (+ 2.39 ng/mL, 95% CI 0.43, 4.35, p = 0.018); 25(OH)D was significantly lower in the PCOS group (- 9.01 ng/mL, 95% CI -14.49, - 3.53 p = 0.001). In our sample, adolescents in both groups had insufficient 25(OH)D level (22 ng/mL) and elevated BMI (32.2 kg/m2).

CONCLUSIONS

Adolescents with PCOS display high levels of AMH and low 25(OH)D levels. Since traditional clinical markers of PCOS may be physiologic in adolescents, AMH and 25(OH)D may be used as surrogate markers of PCOS risk in adolescents.

[Vitamin D and reproductive health]

Vitamin D insufficiency and deficiency in women with infertility is more common than in the population. However, we still do not know the exact mechanisms for the participation of vitamin D in the regulation of reproductive function. The purpose of this study is to analyze actual literature data on the role of vitamin D in the regulation of reproductive system and its influence on using of assisted reproductive technologies for the treatment of infertility. A search was carried out for literary sources published in the NSBI database PubMed, Medline, and others with a search depth of up to 20 years. 135 sources on this topic were studied, of which 54 were included in the analysis. The review presents data obtained in animal studies, in vitro and in clinical studies. Thus, the absence of vitamin D resulted in a dramatical decrease in fertility in both female and male rats and mice, due to the development of hypocalcemia. In vitro studies describe its involvement in the receptive transformation of the endometrium and in the regulation of the immune response during embryo implantation. However, clinical studies often show conflicting results. There is no unequivocal data on the effect of vitamin D levels on spermogram parameters, but a decrease in the pregnancy rate was shown when ovulation was induced in pairs, where a vitamin D deficiency was revealed in men. A meta-analysis published in 2017 showed a decrease in the pregnancy and live birth rate in women with low levels of vitamin D after the use of assisted reproductive technologies (ART). It was not possible to establish whether this decrease depends on oocyte quality or endometrium. There is an opportunity that the effect of vitamin D deficiency on fertility will not come with all forms of infertility. For example, in women with anovulation due to polycystic ovary syndrome, vitamin D deficiency is demonstrated to decrease pregnancy rate in ovulation induction cycles and in ART. Such relationship was not found in women with unexplained infertility.Thus, the role of vitamin D in the pathogenesis of infertility requires further study, as well as the possibilities of therapy in order to increase the effectiveness of infertility treatment methods and assisted reproductive technology programs.

The efficacy of vitamin D combined with clomiphene citrate in ovulation induction in overweight women with polycystic ovary syndrome: a double blind, randomized clinical trial

PURPOSE

The aim of this study was to assess the effect of vitamin D supplementation on ovulation rate in overweight subfertile women with PCOS undergoing ovulation induction.

METHODS

This was a single center, parallel-groups, double-blind, and placebo-controlled randomized trial involving 186 eligible women undergoing induction of ovulation with clomiphene citrate (Clomid®, Aventis) 50 mg tablet twice daily starting from the third day of menstrual cycle and for 5 days combined with either oral Vitamin D (ossofortin®, EVA PHARMA) 10,000 IU twice weekly and calcium (calciprex®, Marcyrl Pharmaceutical Industries) 1250 mg twice daily or to receive a placebo with calcium for three successive induction cycles. The vitamin D or placebo supplementation started 1 month before induction cycles (total four cycles). Cycles were monitored with ultrasound follicle tracking and mid-luteal serum progesterone measurement. The primary outcome was the ovulation rate after three induction cycles.

RESULTS

The study was performed during the period between January 2018 and September 2018, Eighty six (92.5%) women in the treatment group and 73 (78.5%) in the control group had successful ovulation (p = 0.007). The absolute and relative risk reduction was 14% and 65% respectively. Biochemical and clinical pregnancy occurred in 61.3 and 50.5% in the treatment group, and in 49.5 and 39.8% in the control group (p = 0.105 and 0.141 respectively).

CONCLUSION

In subfertile women with PCOS undergoing induction of ovulation, vitamin D supplementation significantly improved the ovulation rate; however, there was no effect on clinical or biochemical pregnancy.

Vitamin D status in endometriosis: a systematic review and meta-analysis

PURPOSE

No consensus exists on the relationship between vitamin D status and endometriosis. The chief aim of our study was to evaluate the association between serum vitamin D levels and endometriosis.

METHODS

We searched for MEDLINE, EMBASE, and China National Knowledge Infrastructure (CNKI) databases for studies elucidated the circulating vitamin D levels in endometriosis. The standardized mean differences (SMDs) or odds ratios (ORs) with their 95% confidence interval (CIs) were calculated to evaluate the association between vitamin D levels and endometriosis.

RESULTS

Nine studies were included in this meta-analysis. The pooled results indicated that women with endometriosis had lower vitamin D status than that in controls (SMD - 0.97 ng/mL, 95% CI - 1.80 to - 0.14; p = 0.02), and vitamin D status had a negative correlation with the severity of the disease (stage III-IV vs stage I-II: SMD - 1.33 ng/mL, 95% CI - 2.54 to - 0.12; p = 0.03). Although it was not statistically significantly different, hypovitaminosis D had a tendency to be associated with endometriosis (OR 2.77, 95% CI 0.85-6.08, p = 0.10). Heterogeneity was high among included studies. Subgroup analyses revealed that women with no hormone use had lower vitamin D status when compared with controls (SMD - 1.38 ng/mL, 95% CI - 2.59 to - 0.18; p = 0.02). For studies which sample size < 100, serum vitamin D levels were significantly lower in patients than that in controls (SMD - 0.65 ng/mL, 95% CI - 1.19 to - 0.11; p = 0.02).

CONCLUSIONS

Women with endometriosis had lower vitamin D status when compared with controls, and a negative relationship between vitamin D levels and severity of endometriosis was observed. In addition, hypovitaminosis D was a potential risk factor for endometriosis.

Roles of Vitamin D in Reproductive Systems and Assisted Reproductive Technology

Vitamin D, an essential steroid hormone in the human body, plays an important role in not only the regulation of calcium and phosphorus metabolism, but also in various physiological processes, such as cell differentiation and apoptosis, inflammation, and insulin resistance. Vitamin D receptors are widely distributed in male and female reproductive systems, suggesting that vitamin D is essential for fertility. Because vitamin D deficiency is highly prevalent around the world, this review aims to discuss the potential functions of vitamin D in male and female reproductive systems and the associations between vitamin D and assisted reproductive technology (ART) outcomes. Vitamin D is involved in many physiological reproductive processes, including steroidogenesis, spermatogenesis, and acrosome reaction. It is correlated with sperm quality, ovarian reserve, polycystic ovarian syndrome, and endometriosis, among others. Controversial clinical findings on vitamin D levels and ART outcomes were revealed in this review, and demonstrations of efficacy for human fertility in randomized controlled trials of vitamin D supplementation are notably lacking. Thus, further studies are highly required involving molecular mechanisms among different species and human populations, as well as randomized controlled trials.

Gut microbiota dysbiosis in polycystic ovary syndrome: association with obesity - a preliminary report

The objective was to explore if and how the microbiota changed in polycystic ovary syndrome (PCOS) women compared with healthy women. Eight obese PCOS (PO group), 10 nonobese PCOS (PN group), and nine healthy normal weight women (control) (C group) were enrolled. Insulin (INS), testosterone (T), follicle-stimulating hormone (FSH), luteinizing hormone (LH), estrogen (E2), and dehydroepiandrosterone (DHEA) were detected with radioimmunoassay. Antimullerian hormone (AMH), fasting glucose, and hemoglobin A1c (HbA1c) were determined by a chemiluminescence immunoassay, glucose oxidase method, and HPLC, respectively. Gut microbiota composition was evaluated by PCR. Alpha diversity was assessed using Chao1 and the Shannon index. PCOS women showed significantly higher T, LH, and LH/FSH and lower FSH levels than the C group (p < 0.05). The AMH level was significantly higher in the PO than in the PN group (p < 0.05). The PO group presented a significantly higher fasting INS level and HMOA-IR scores than the other groups, lower observed SVs and alpha diversity than the C group, higher beta diversity than the PN group (p < 0.05), and decreased abundances of genera (mainly butyrate producers). Regression analysis showed that decreased abundances of several genera were correlated with higher circulating T and impaired glucose metabolism. PCOS is associated with changes in the gut microbiota composition. Obesity has a driving role in the development of dysbiotic gut microbiota in PCOS.

Pre-conception 25-hydroxyvitamin D (25(OH)D) and fecundability

STUDY QUESTION

Is pre-conception 25(OH)D associated with the per cycle probability of conception, i.e fecundability, in a prospective cohort study?

SUMMARY ANSWER

There are suggestive associations of high 25(OH)D (at least 50 ng/ml) with increased fecundability and low 25(OH)D (<20 ng/ml) with reduced fecundability, but the estimates were imprecise.

WHAT IS KNOWN ALREADY

Vitamin D has been associated with reproductive function and fertility in animal studies, but few human studies exist.

STUDY DESIGN, SIZE, DURATION

This community-based prospective cohort study included 522 women attempting to become pregnant between 2010 and 2016. The women completed online daily and monthly diaries until a positive home pregnancy test was observed or 12 months had elapsed.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study included women from central North Carolina who were aged 30-44 with no history of infertility, with no more than 3 months of attempt time at recruitment. Women recorded vaginal bleeding so that the ongoing number of attempt cycles could be counted and used to quantify a woman's pregnancy attempt time. Blood collected at the study entry was analysed for 25(OH)D using liquid chromatography tandem mass spectrometry. Associations with fecundability were estimated with a log-binomial discrete time-to-event model.

MAIN RESULTS AND THE ROLE OF CHANCE

Among 522 women, 257 conceived during the study. The mean age was 33 years and the mean 25(OH)D was 36 ng/ml. There was an estimated 10% higher fecundability with each 10 ng/ml increase in 25(OH)D (fecundability ratio (FR) 1.10, 95% CI: 0.96, 1.25). The suggestive dose-response association with the continuous measure of 25(OH)D was driven by women in the lowest and the highest categories of 25(OH)D. Compared to women with 25(OH)D of 30-40 ng/ml, women below 20 ng/ml had an estimated 45% reduction in fecundability (FR (CI): 0.55 (0.23, 1.32)), and women with at least 50 ng/ml had an estimated 35% increase in fecundability (FR (CI): 1.35 (0.95, 1.91)). Across these three categories (25(OH)D of <20 ng/ml, 30-40 ng/ml and > 50 ng/ml), the probability of taking longer than 6 months to conceive was, respectively, 51% (17%, 74%), 28% (17%, 39%) and 15% (10%, 37%).

LIMITATIONS, REASONS FOR CAUTION

While the distribution of 25(OH)D was wide, the number of observed cycles with high 25(OH)D (N = 107) or low 25(OH)D (N = 56) was small.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings are consistent with prior reports of reduced fertility in women with 25(OH)D concentrations below the clinically defined deficiency level (20 ng/ml). Further studies are needed to evaluate the possible reproductive benefits of considerably higher 25(OH)D concentration (>50 ng/ml).

STUDY FUNDING/COMPETING INTEREST(S)

This research was supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health (NIH) under award numbers R00HD079659 and R01HD067683 and supported in part by the Intramural Research Program of the National Institute of Environmental Health Sciences, under projects ES103086, ES049003 and ES044003. ClearBlue ovulation predictor kits were generously donated to AMZJ and AJW by Swiss Precision Diagnostics. Drs Wilcox and Jukic report non-financial support from Swiss Precision Diagnostics during the conduct of the study; Dr Jukic reports non-financial support from Theralogix, LLC, outside the submitted work. Otherwise there are no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Hyperandrogenemia and insulin resistance: The chief culprit of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is one of the most common systemic reproductive endocrine diseases, which has a variety of effects on a woman's health. Because of the involvement of multiple pathways and the lack of common clues, PCOS demonstrates multifactorial properties and heterogeneity of symptoms. Recent studies have demonstrated that the core etiology and primary endocrine characteristics of PCOS are hyperandrogenemia (HA) and insulin resistance (IR). HA and IR are the main causes of PCOS and they can interplay each other in the occurrence and development of PCOS. Just because of this, the study about the effects of HA and IR on pathophysiology of various related symptoms of PCOS is very important to understand the pathogenesis of PCOS. This paper reviews the main symptoms of PCOS, including neuroendocrine disorders, reproductive processes, dyslipidemia, obesity, hypertension, nonalcoholic fatty liver disease (NAFLD), and sleep disordered breathing, which seriously affect the physical and mental health of PCOS women. The increasing knowledge of the development pattern of HA and IR in PCOS suggests that changes in diet and lifestyle, and the discovery of potential therapeutic agents may improve PCOS. However, further studies are needed to clarify the mutual influence and relation of HA and IR in development of PCOS. This review provides an overview of the current knowledge about the effects of HA and IR on PCOS.

Type 2 Diabetes Mellitus, Insulin Resistance, and Vitamin D

PURPOSE OF REVIEW

There is a growing, largely inconsistent, literature on the role of vitamin D in association with type 2 diabetes, insulin resistance/insulin secretion, glycemic indices, and complications of type 2 diabetes. Pathophysiologic, bystander, preventive, and treatment roles of vitamin D have all been proposed. In this focused review, we attempt to organize and clarify our current information in this area.

RECENT FINDINGS

Clinical study interpretation is difficult because of variability in dosage, dosage form, study duration, and populations studied, as well as recently reported normal human polymorphisms in vitamin D synthesis and catabolism, vitamin D-binding protein, and vitamin D receptors in addition to a host of potential epigenetic confounders. Low vitamin D status appears to be associated with type 2 diabetes and most other insulin resistance disorders reported to date. The extraskeletal benefits of supplementation/repletion in these disorders in our species, with a few highlighted exceptions, remain to be established. This focused review attempts to summarize our current knowledge in this burgeoning area through a review of key meta-analyses, observational studies, randomized control trials, and Mendelian randomization studies and will hopefully serve as a guide to indicate future research directions and current best practice.

The effects of vitamin D supplementation on metabolic profiles and gene expression of insulin and lipid metabolism in infertile polycystic ovary syndrome candidates for in vitro fertilization

BACKGROUND

Vitamin D deficiency in women diagnosed with polycystic ovary syndrome (PCOS) remarkably decreases the chance of pregnancy, which might be related to its impact on metabolic abnormalities in these patients. It is hypothesized that vitamin D supplementation influences metabolic profile of these patients and indirectly might affect fertility and the outcomes. Therefore, this study was conducted to determine the effects of vitamin D supplementation on the levels of anti-Müllerian hormone (AMH), metabolic profiles, and gene expression of insulin and lipid metabolism in infertile women with PCOS who were candidate for in vitro fertilization (IVF).

METHODS

This study was a randomized, double-blinded, placebo-controlled trial conducted among 40 infertile women, aged 18-40 years, diagnosed with PCOS and was candidate for IVF. Participants were randomly assigned into two intervention groups for receiving either 50,000 IU vitamin D or placebo (n = 20 each group) every other week for 8 weeks. Gene expression for insulin and lipid metabolism was conducted using peripheral blood mononuclear cells (PBMCs) of women with PCOS, via RT-PCR method.

RESULTS

Vitamin D supplementation led to a significant reduction in serum AMH (- 0.7 ± 1.2 vs. - 0.1 ± 0.5 ng/mL, P = 0.02), insulin levels (- 1.4 ± 1.6 vs. -0.3 ± 0.9 μIU/mL, P = 0.007), homeostatic model of assessment for insulin resistance (- 0.3 ± 0.3 vs. -0.1 ± 0.2, P = 0.008), and a significant increase in quantitative insulin sensitivity check index (+ 0.009 ± 0.01 vs. + 0.001 ± 0.004, P = 0.04), compared with the placebo. Moreover, following vitamin D supplementation there was a significant decrease in serum total- (- 5.1 ± 12.6 vs. + 2.9 ± 10.9 mg/dL, P = 0.03) and LDL-cholesterol levels (- 4.5 ± 10.3 vs. + 2.5 ± 10.6 mg/dL, P = 0.04) compared with the placebo.

CONCLUSION

Overall, the findings of this trial supported that 50,000 IU vitamin D supplementation every other week for 8 weeks had beneficial effects on insulin metabolism, and lipid profile of infertile women with PCOS who are candidate for IVF. These benefits might not be evident upon having sufficient vitamin D levels.

TRIAL REGISTRATION

This study was retrospectively registered in the Iranian website ( www.irct.ir ) for clinical trials registration ( http://www.irct.ir : IRCT20170513033941N27).

Circulating Levels of Vitamin D3 and Leptin in Lean Infertile Women with Polycystic Ovary Syndrome

OBJECTIVE

The objective of this study is to measure levels of Vitamin D3 and leptin and assess their relation of each to the pathogenesis of polycystic ovary syndrome (PCOS).

DESIGN

This was a cohort observational study.

SETTINGS

This study was conducted at the Department of Obstetrics and Gynecology, Tanta University.

MATERIALS AND METHODS

Ninety lean women were enrolled in this study and were allocated into two groups with 45 patients in each group: the first group (study group) who are lean women with PCOS and the second group (control group) who are the lean infertile patients without PCOS. Blood samples were collected and tested for study parameters.

RESULTS

There were no significant differences regarding demographic characteristics between both groups. The differences were in ovarian volume and hormonal profiles. Serum leptin was found to be significantly increased in lean PCOS than in control groups. Vitamin D3 levels were found to be lower in the lean PCOS group than in control group.

CONCLUSION

Lean PCOS women are a unique group with specific hormonal profiles different from the typical PCOS profiles. Leptin and Vitamin D3 may have a role in the pathogenesis of lean PCOS, but large studies are still required regarding this unique group.