[Polycystic ovary syndrome: new and promising treatment methods]

Polycystic Ovary Syndrome (PCOS) - is a polygenic endocrine disorder caused by genetic, hormonal, and epigenetic factors. The importance of addressing PCOS lies in its prevalence, affecting approximately 10 to 13% of women, as well as the associated health conditions that can have a negative impact on women's lives, including infertility, dermatological manifestations of hyperandrogenism (such as hirsutism and acne), cardiovascular pathologies, metabolic disorders, and psychoemotional disorders. Currently, many theories of the development of this disease have been proposed, and as a consequence of methods of influencing and treating it. According to the clinical recommendations of the Ministry of Health of the Russian Federation, modifying the patient's lifestyle forms the basis of comprehensive therapy. We have analyzed about 60 articles on various dietary approaches to the treatment of PCOS, sourced from PubMed, Nature Reviews, Oxford Academic, Clinical Nutrition, EJOG, ScienceDirect, and MDPI. The Mediterranean diet, the DASH diet, the ketogenic diet and the low-carb diet have proven themselves the best. Also, it's necessary to add vitamin D, E, folic acid, calcium, various pro- and prebiotics to a woman's diet. Currently, the use of inositol and GPP-1 is becoming a promising method of PCOS therapy. According to the results of the analysis, a positive effect of diet therapy on the anthropometric and biochemical parameters was noted. Based on the analysis, a positive effect of diet therapy on anthropometric and biochemical parameters has been observed. It is crucial to consider the individual characteristics of each patient and not rely solely on drug therapy when approaching the treatment of PCOS.

The beneficial influences of vitamin D intake on inflammation and oxidative stress in infertile women with polycystic ovary syndrome

Objective

Oxidative stress and inflammation play a vital function in the pathophysiology of polycystic ovary syndrome (PCOS) and infertility. The aim of this work was to control the impacts of vitamin D intake on metabolic profiles in infertile subjects with PCOS.

Trial design and methods

This randomized, double-blinded, placebo-controlled clinical trial was carried out among 40 infertile women with PCOS. Subjects were randomly divided into two intervention groups to take either 50 000 IU vitamin D (n=20) or placebo (n=20) weekly for 8 weeks. Metabolic profiles and few inflammatory cytokines expression evaluated on peripheral blood mononuclear cells (PBMCs) of participants, using real-time polymerase chain reaction (RT-PCR) method.

Results

Vitamin D intake decreased high-sensitivity C-reactive protein (hs-CRP) (-0.9±1.1 vs. 0.3±0.9 mg/l, P=0.002) and elevated total antioxidant capacity (TAC) levels (49.2±60.2 vs. -50.6±161.8 mmol/l, P=0.02) compared with placebo; but no significant effects on other metabolic parameters were observed. Moreover, a significant downregulation of tumor necrosis factor alpha (TNF-α) expression (P=0.03) was observed after taking vitamin D compared with the placebo.

Conclusions

Overall, vitamin D intake for eight weeks had beneficial impacts on hs-CRP, TAC, and TNF-α among infertile women with PCOS.

Mitigating bisphenol A-induced apoptosis in KGN cells: the therapeutic role of 1,25-dihydroxyvitamin D3 through upregulation of PGC-1α expression and inhibition of the mitochondrial cytochrome c pathway

PURPOSE

This study investigated the potential of 1,25-dihydroxyvitamin D3 (1,25(OH)2VD3) to mitigate bisphenol A (BPA)-induced apoptosis in human ovarian granulosa KGN cells with the aim of establishing a theoretical foundation for understanding of how vitamin D improved ovarian function in patients with polycystic ovary syndrome (PCOS).

METHODS

The impact of varying concentrations of BPA and 1,25(OH)2VD3 on KGN cell viability was elucidated. It was established that BPA-induced apoptosis in KGN cells. Subsequently, KGN cells underwent pretreatment with 1,25(OH)2VD3, followed by exposure to BPA. The apoptosis rate, reactive oxygen species (ROS) levels, and mitochondrial function of the cells were meticulously assessed, along with the expression levels of genes associated with apoptosis as well as antioxidant and mitochondrial biogenesis.

RESULTS

BPA induced a notable increase in apoptosis (P < 0.001) and oxidative stress (P < 0.001) in KGN cells, accompanied by a significant reduction in mitochondrial membrane potential (P < 0.001) and severe impairment of mitochondrial function. Following pretreatment of KGN cells with 1,25(OH)2VD3, there was a significant decrease in the apoptosis rate (P = 0.004), coupled with a reduction in ROS production (P = 0.002). Concomitantly, the upregulation of PGC-1α (P = 0.009) and SOD (P = 0.018) was observed, while mRNA expression of BAX (P = 0.011), Cyt c (P = 0.001), Apaf-1 (P = 0.012), caspase-9 (P < 0.001), and caspase-3 (P = 0.011) was downregulated. Notably, the mitigation of mitochondrial damage was evident through restored mitochondrial membrane potential (P < 0.001), as corroborated by electron microscope results.

CONCLUSIONS

1,25(OH)2VD3 mitigated BPA-induced damage and apoptosis in KGN cells by upregulating the expression of PGC-1α and impeding the mitochondrial cytochrome c (Cyt c) apoptotic pathway. This study established a novel theoretical foundation for utilizing vitamin D in the treatment of PCOS patients.

Vitamin D3 among neonates born after in vitro fertilization compared with neonates from the general population

INTRODUCTION

Sufficient levels of vitamin D have been associated with higher chances for both clinical pregnancy and live birth among women undergoing assisted reproductive techniques, whereas low levels of maternal vitamin D have been associated with preeclampsia and late miscarriage. In Denmark, subgroups at risk for low vitamin D levels, including neonates and toddlers, are recommended to use supplementation. The aim was to study the level of vitamin D3 among neonates born after in vitro fertilization compared with neonates from the general population.

MATERIAL AND METHODS

In this cohort study a random sample of 1326 neonates representing the general population and 1200 neonates conceived by in vitro fertilization born in Denmark from 1995 to 2002 were identified from registries covering the whole Danish population. Information on use of assisted reproduction was collected from the Danish In Vitro Fertilization register, ICD-10 code: DZ358F. 25-Hydroxyvitamin D was measured from dried blood spots routinely collected by heel prick 48-72 h after birth and corrected according to the hematocrit fraction for capillary blood of neonates. Linear regression analysis was performed, both crude and adjusted, for predefined putative confounders, identified through directed acyclic graphs.

RESULTS

Vitamin D3 analysis could be performed from a total of 1105 neonates from the general population and 1072 neonates conceived by in vitro fertilization that were subsequently included in the study. The median vitamin D3 was 24.0 nmol/L (interquartile range [IQR] 14.1-39.3) and 33.0 nmol/L (IQR 21.3-48.8) among neonates from the general population and neonates conceived by in vitro fertilization, respectively. The adjusted mean difference between neonates from the general population and those conceived by in vitro fertilization was 6.1 nmol/L (95% confidence interval 4.1-8.1).

CONCLUSIONS

In this study, children born after in vitro fertilization have a higher vitamin D3 than a random sample of neonates in Denmark.

[Resolution of the national interdisciplinary council of experts "High-dose vitamin D (Devilam) in the practice of an obstetrician-gynecologist"]

On March 28, 2024, the Council of Experts "High-dose vitamin D (Devilam) in the practice of obstetrician-gynecologist, gynecologist and endocrinologist" was held in Moscow with the participation of leading experts gynecologists, endocrinologists and obstetricians-gynecologists, during which new possibilities for the use of high-dose vitamin D in patients of various ages who need correction of existing vitamin D deficiency or insufficiency.

Long pentraxin 3 and vitamin D receptor mRNA expression pattern of cumulus granulosa cells isolated from PCOS oocytes at different stages of nuclear maturation

BACKGROUND

A fine-tuned pro-inflammatory and anti-inflammatory balance in the follicular unit is essential for cumulus expansion and successful ovulation. While the long pentraxin 3 (PTX3) gene is required for the expansion of cumulus cells (CCs), ovulation, resumption of meiosis and fertilization, the vitamin D receptor gene (VDR-X2) is required for intra-follicle redox balance. This study was planned to determine the expression pattern of VDR-X2 and PTX3 mRNA in CCs isolated from germinal vesicle (GV), metaphase I (MI), and metaphase II (MII) oocytes of PCOS patients with ovulatory dysfunction.

METHODS

The relative expression of CC-PTX3 and CC-VDR-X2 mRNA were evaluated using qRT-PCR in a total of 79 CC samples collected from individual cumulus-oocyte complex of 40 infertile patients (20 PCOS and 20 non-PCOS normal responders) who underwent ovarian stimulation with the GnRH antagonist protocol.

RESULTS

Relative PTX3 mRNA expressions of CCMI-control and CCMII-control showed 3- and 9-fold significant upregulation compared to CCGV-control, respectively. The relative PTX3 mRNA expression of CCMII-control increased approximately three fold compared to CCMI-control. Compared to CCGV-pcos, a 3-fold increase was noted in the relative PTX3 mRNA expression of CCMI-pcos and an approximately 4-fold increase in the PTX3 mRNA expression of CCMII-pcos. Relative PTX3 mRNA expression values of CCMII-pcos and CCMI-pcos were similar. A 6-fold upregulation of relative PTX3 mRNA and a 4-fold upregulation of VDR-X2 mRNA were detected in CCMII-control compared to CCMII-pcos. CC-VDR-X2 expression patterns of the PCOS and control groups overlapped with the CC-PTX3 pattern. Fertilization rates of the PCOS group exhibiting failed transcript expression were similar to normal responders.

CONCLUSION

The fact that relative CC-PTX3 and CC-VDR mRNA expression does not increase during the transition from MI to MII stage in PCOS as in normal responders suggests that PTX3 and VDR expression may be defective in cumulus cells of PCOS patients with ovulatory dysfunction.

The Associations of Vitamin D with Ovarian Reserve Markers and Depression: A Narrative Literature Review

Since the identification of vitamin D receptors in both the female reproductive tract and the central nervous system, further data have shown that vitamin D is involved in the processes of reproductive and mental health. This paper reviews current research on the associations of vitamin D with ovarian reserve markers and depression and discusses the potential role of vitamin D in their relationships. There have been numerous studies reporting that vitamin D was significantly related to ovarian reserve markers and depression in basic or clinical research, but some observational and interventional clinical studies have shown inconsistent results. Nevertheless, recent meta-analyses of interventional studies have provided promising results showing that vitamin D supplementation significantly improves ovarian reserve metrics, especially in a subgroup of women with normal or diminished ovarian reserve, and decreases depressive symptoms and risk. The demonstration of an association of vitamin D with both ovarian reserve and depression could suggest that vitamin D may be another important key in explaining female reproductive depression. Larger-scale studies in standardized settings will be needed in order to gain further insight into the role of vitamin D in female reproduction and depression.

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.

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.

Influence of Vitamin D supplementation on reproductive outcomes of infertile patients: a systematic review and meta-analysis

BACKGROUND

Low vitamin D status has been associated with an increased risk for infertility. Recent evidence regarding the efficacy of vitamin D supplementation in improving reproductive outcomes is inconsistent. Therefore, this systematic review was conducted to investigate whether vitamin D supplementation could improve the reproductive outcomes of infertile patients and evaluate how the parameters of vitamin D supplementation affected the clinical pregnancy rate.

METHODS

We searched seven electronic databases (CNKI, Cqvip, Wanfang, PubMed, Medline, Embase, and Cochrane Library) up to March 2022. Randomized and cohort studies were collected to assess the reproductive outcomes difference between the intervention (vitamin D) vs. the control (placebo or none). Mantel-Haenszel random effects models were used. Effects were reported as odds ratio (OR) and their 95% confidence interval (CI). PROSPERO database registration number: CRD42022304018.

RESULTS

Twelve eligible studies (n = 2352) were included: 9 randomized controlled trials (RCTs, n = 1677) and 3 cohort studies (n = 675). Pooled results indicated that infertile women treated with vitamin D had a significantly increased clinical pregnancy rate compared with the control group (OR: 1.70, 95% CI: 1.24-2.34; I² = 63%, P = 0.001). However, the implantation, biochemical pregnancy, miscarriage, and multiple pregnancy rates had no significant difference (OR: 1.86, 95% CI: 1.00-3.47; I² = 85%, P = 0.05; OR: 1.49; 0.98-2.26; I² = 63%, P = 0.06; OR: 0.98, 95% CI: 0.63-1.53; I² = 0%, P = 0.94 and OR: 3.64, 95% CI: 0.58-11.98; I² = 68%, P = 0.21). The improvement of clinical pregnancy rate in the intervention group was influenced by the vitamin D level of patients, drug type, the total vitamin D dosage, the duration, administration frequency, and daily dosage of vitamin D supplementation. The infertile women (vitamin D level < 30 ng/mL) treated with the multicomponent drugs including vitamin D (10,000-50,000 IU or 50,000-500,000 IU), or got vitamin D 1000-10,000 IU daily, lasting for 30-60 days could achieve better pregnancy outcome.

CONCLUSION

To the best of our knowledge, this is the first meta-analysis systematically investigated that moderate daily dosing of vitamin D supplementation could improve the clinical pregnancy rate of infertile women and reported the effects of vitamin D supplementation parameters on pregnancy outcomes. A larger sample size and high-quality RCTs are necessary to optimize the parameters of vitamin D supplementation to help more infertile patients benefit from this therapy.

Sun Exposure Score and Vitamin D Levels in Moroccan Women of Childbearing Age

Sunlight exposure is an essential source of vitamin D for many humans. However, hypovitaminosis D is a global public health problem. This study aimed to develop and validate a sun exposure score (SES) and correlate it with serum 25-hydroxyvitamin D levels in women of childbearing age. One hundred and sixty women aged 18 to 45 years residing in Meknes, Morocco, were included. A questionnaire estimating the sun exposure score and blood analysis of serum 25-OHD concentration were performed. The questionnaire's reliability and construct validity were evaluated using Cronbach's alpha and factor analysis. Spearman's test was used to assess the correlation between SES and 25-OHD levels. The score's reliability and construct validity were good, with Cronbach's alpha values >0.70 and factorial saturation ranging from 0.696 to 0.948. Serum 25-OHD levels were significantly associated with the total sun exposure score, and all SES domains (Rho was 0.615 (p < 0.0001), 0.307 (p < 0.0001), 0.605 (p < 0.0001), and 0.424 (p < 0.0001) for total SES, indoor exposure domain, outdoor exposure domain, and sun protection practice domain, respectively). In addition, median 25-OHD levels increased significantly when sun exposure was changed from insufficient to sufficient (p < 0.0001). The results suggest that the sun exposure score could be used as a clinical tool to assess vitamin D levels in women of childbearing age.

Effects of Vitamin D on Fertility, Pregnancy and Polycystic Ovary Syndrome-A Review

Polycystic ovary syndrome (PCOS) is one of the most common endocrine reproductive disorders in women. Vitamin D deficiency is also quite common in this condition. The degree of vitamin D deficiency correlates with the severity of PCOS. Both male and female vitamin D levels play a role in fertility and affect the outcomes of in vitro fertilization (IVF). Moreover, fertility and IVF indicators are improved by vitamin D not only in healthy women but in those diagnosed with PCOS. Both vitamin D deficiency and PCOS increase pregnancy-related complications. Vitamin D supplementation and optimal vitamin D levels decrease both maternal and fetal risk for complications and adverse events. Furthermore, vitamin D supplementation may ameliorate or even prevent pregnancy-related reversible bone loss in mothers. This review emphasizes the roles of vitamin D deficiency and vitamin D supplementation and their correlation with PCOS regarding reproductive health.

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.

Metabolic Syndrome and PCOS: Pathogenesis and the Role of Metabolites

Polycystic ovary syndrome (PCOS) is one of the most common endocrine diseases among women of reproductive age and is associated with many metabolic manifestations, such as obesity, insulin resistance (IR) and hyperandrogenism. The underlying pathogenesis of these metabolic symptoms has not yet been fully elucidated. With the application of metabolomics techniques, a variety of metabolite changes have been observed in the serum and follicular fluid (FF) of PCOS patients and animal models. Changes in metabolites result from the daily diet and occur during uncommon physiological routines. However, some of these metabolite changes may provide evidence to explain possible mechanisms and new approaches for prevention and therapy. This article reviews the pathogenesis of PCOS metabolic symptoms and the relationship between metabolites and the pathophysiology of PCOS. Furthermore, the potential clinical application of some specific metabolites will be discussed.

Vitamin D deficiency as a risk factor for endometriosis in Iranian women

PURPOSE

Vitamin D (Vit D), as an immunomodulator, has been hypothesized to play a critical role in the pathogenesis of endometriosis. Thus, in this study, we evaluated whether there is an association between 25-hydroxyvitamin D [25(OH)D] and susceptibility to endometriosis in Iranian women.

METHODS

Women at reproductive age, including 56 healthy women and 54 patients with endometriosis, were enrolled in the study. Serum levels of 25(OH)D, calcium, parathyroid hormone (PTH), and peritoneal fluid (PF) levels of 25(OH)D were assessed.

RESULTS

The serum and PF levels of 25(OH)D in the patients with endometriosis were significantly lower than the control group (P = 0.001 and P = 0.03, respectively). Subjects with serum levels of 25(OH)D lower than 20 ng/mL had a 2.7 times higher risk of endometriosis than people with 25(OH)D serum levels higher than 20 ng/mL (non-deficient) (OR = 2.7, 95 % confidence interval: 1.24-5.80, P = 0.01). The serum levels of calcium and PTH were significantly lower and higher in patients with endometriosis compared with controls, respectively (P < 0.001, P = 0.02, respectively). Also, the serum levels of 25(OH)D were lower in stages I-II endometriosis than stage III-IV; however, no significant difference was observed.

CONCLUSION

Our findings showed that people with Vit D deficiency are at higher risk of endometriosis.

[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.

Ovarian 25OH-vitamin D production in young women affected by polycystic ovary syndrome

INTRODUCTION

Vitamin D is involved in the regulatory mechanisms of ovarian function and is frequently low in PCOS patients. Since obesity and hyperinsulinemic state negatively influenced vitamin D levels, therefore, we evaluated the production of vitamin D at the ovarian level only in lean and normoinsulinemic PCOS subjects. Basal, GnRH analogue-induced ovarian production of 25OH-vitamin D (VitD) and a direct sampling at ovarian vein level were investigated.

METHODS

Basal and GnRH analogue-induced hormone levels were evaluated at peripheral level in 45 subjects, aged 18-39 years, and in 22 healthy women with age- and BMI-matched as controls. In 12 PCOS patients, undergoing laparoscopy, a venous sampling at both peripheral and ovarian level was further done. All subjects presented low VitD levels, appropriate to the season and with no difference between PCOS and control subjects.

RESULTS

GnRH analogue significantly stimulated plasma LH, FSH, 17-OHP and estradiol secretion (p from < 0.05 to < 0.001 vs basal levels), whereas no effect was observed on both serum AMH and VitD concentrations in all groups. A significant difference (p < 0.006), between peripheral and ovarian veins, was observed in both AMH and estradiol levels in PCOS subjects, while no gradient of VitD was detected.

CONCLUSIONS

All patients presented with low VitD levels. The absence of any VitD variation, both at basal and after GnRH analogue administration, or at peripheral-ovarian vein gradient, suggests no pituitary-ovarian axis involvement in VitD production or its direct ovarian production in lean and normoinsulinemic PCOS subjects.

Vitamin D and Polycystic Ovary Syndrome: a Narrative Review

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders of reproductive age women and contributes to metabolic dysfunctions including insulin resistance (IR) and dyslipidemia. Vitamin D is a steroid hormone, which is involved in calcium metabolism and bone structure and has a potential role in the prevention of many illnesses, including cancers, autoimmune disorders, hypertension, diabetes, and obesity. Recently, it has been reported that vitamin D deficiency was a common complication of PCOS and vitamin D status was associated with reproductive ability, metabolic alterations, and mental health of PCOS patients. This review summarizes the advances between vitamin D status and the pathophysiological process of PCOS. Vitamin D level was negatively associated with serum androgen level. Vitamin D treatment could reduce serum androgen and anti-MüllerianHormone (AMH) levels, and decrease endometrial thickness, which resulted in improvement of menstrual cycle and folliculogenesis of PCOS patients. Moreover, vitamin D concentrations were negatively correlated with parameters of IR and body fat mass. Vitamin D supplementation has beneficial effects on IR and lipid metabolism. In addition, a positive of vitamin D on mental health of PCOS patients was proposed. Understanding the relationship between vitamin D status and the symptoms of PCOS patients is of great clinical significance to treat and prevent the progression of PCOS.

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.

Follicular fat-soluble vitamins as markers of oocyte competency

The main aim of this prospective study was to investigate the effect of the concentration of fat-soluble vitamins A, D, E and K in individual follicles on oocyte quality and developmental competence. The analysis was performed on 313 follicular fluid (FF) samples from 50 patients undergoing ovarian stimulation with intracytoplasmic sperm injection. We demonstrated that the mean concentration of individual vitamins in FF correlated with their level in serum (p < 0.0001). The levels of vitamin D in FF were higher than in serum, while the opposite was observed for other analyzed vitamins. We did not observe a correlation between FF vitamin D concentration with fertilization success. However, we observed its association with embryo development status on day 3. Moreover, we showed a statistically significant negative correlation between the mean day 5 embryo score and the concentration of vitamin D in serum (rS = -0.68 p = 0.01) and follicular fluid (rS = -0.71 p = 0.01). Our study showed that FF concentration of vitamin A and E was helpful in the prediction of fertilization success of each individual oocyte. Moreover, vitamin A and E concentrations in FF were associated with status of embryo development on the third day of culture. Vitamin A was also associated with the embryo quality on day 2 and the embryo development status on day 5 after fertilization. In conclusion, a combination of FF vitamin analysis and routine morphological assessment could allow for a more accurate and sensitive method of determining embryonic developmental competence and enable the selection of a better embryo to transfer and perhaps translating into an increased chance of pregnancy.Abbreviations: in vitro fertilization: IVF; anti-Mullerian hormone: AMH; follicular fluid: FF; intracytoplasmic sperm injection: ICSI; top quality: TQ; vitamin D binding globulin level: VDBP; assisted reproductive technology: ART.

Effect of vitamin D status on normal fertilization rate following in vitro fertilization

BACKGROUND

Vitamin D plays critical role in the female reproductive system. It seems that vitamin D is associated with clinical pregnancy outcomes of assisted reproductive technologies (ART), but its role remains elusive. This study is aimed to establish whether vitamin D is associated with clinical outcomes of in vitro fertilization (IVF).

METHODS

The cross-sectional study was carried out from January 1st 2017 to December 31st 2017. A total of 848 patients who had indications for IVF were enrolled. The patients were classified by serum 25 (OH) D quartiles. The outcome parameters of IVF were compared in each group, including normal fertilization rate, high quality embryo rate, clinical pregnancy rate, implantation rate and live birth rate.

RESULTS

The median 25 (OH) D concentration was 15.25 ng/ml. Serum 25 (OH) D levels in women varied with the seasons. We found that serum 25 (OH) D levels were higher in autumn than other seasons, and the lowest level occurred in spring. Follicular fluid (FF) vitamin D levels were positively correlated with serum vitamin D levels (r = 0.85, P < 0.001). The levels of FF vitamin D were significantly higher than the levels of serum vitamin D (P < 0.001). Normal fertilization rates were significantly different among four groups (P = 0.007). The group of women with the highest serum 25 (OH) D levels had the highest normal fertilization rate. However, the clinical pregnancy rate, implantation rate and live birth rates were not significantly different among the four groups when the age, BMI, AMH, seasons of blood drawing, COH protocol, high quality embryo rate and number of embryos transferred were adjusted. In addition, we found that serum 25 (OH) D levels were significantly higher in patients received IVF than patients received R-ICSI (P = 0.013).

CONCLUSIONS

Among Chinese women, lower serum vitamin D levels are associated with a lower fertilization rate in IVF. However, vitamin D level was not associated with the clinical pregnancy and live birth rate following IVF.