Effects of vitamin D supplementation on metabolic and endocrine parameters in PCOS: a randomized-controlled trial

Gut microbiota and ovarian diseases: a new therapeutic perspective

The gut microbiota is a complex community of microorganisms that inhabit the human gastrointestinal tract, helping to maintain the ecological balance of the body's internal and external environments. Disruptions in the composition and diversity of gut microbiota, as well as changes in their metabolic functions, can link to the development and severity of conditions such as premature ovarian insufficiency, polycystic ovary syndrome, and ovarian tumors. This article thoroughly reviews recent research on the connection between gut microbiota and ovarian diseases, providing fresh perspectives on their prevention, pathogenesis, and treatment.

The role of macrophages in polycystic ovary syndrome: A review

Polycystic ovary syndrome (PCOS) is a common endocrine disorder among fertile women, which is influenced by genetics and environment. A recent study revealed that PCOS patients were in a chronic inflammatory state, and they had abnormally activated macrophages. This paper introduces the relationship between PCOS and macrophages. The forkhead box protein O1 (FOXO-1), migration inhibitory factor, sympathetic conservation disorder, and vitamin D are believed to influence macrophages in PCOS. There is evidence that PCOS-associated abnormalities are associated with macrophages, including insulin resistance, obesity, hyperandrogenism (HA), hyperhomocysteinemia (HHcy), cardiometabolic disorder and gut microbiota dysbiosis. This review summarizes the research status of macrophages in PCOS. Macrophages might be a potential PCOS treatment candidate.

The impact of vitamin D supplementation on glycemic control and lipid metabolism in polycystic ovary syndrome: a systematic review of randomized controlled trials

BACKGROUND

Polycystic ovary syndrome (PCOS) is a prevalent endocrine condition affecting both metabolic and reproductive health in women. The impact of vitamin D on metabolic regulation has attracted growing interest. The purpose of this study is to investigate the impact of vitamin D supplementation on key metabolic parameters-namely blood glucose, insulin, and lipid levels-in individuals with PCOS.

METHODS

A systematic review was conducted to identify relevant studies in PubMed, Embase, Cochrane Library, Web of Science, and ClinicalTrials.gov. The search focused on randomized controlled trials (RCTs) evaluating the impact of vitamin D supplementation in patients with PCOS. Meta-analysis was performed using RevMan 5.3 software, and study quality was evaluated with the Cochrane Risk of Bias Tool. In addition, outcome-related evidence was graded using the GRADE system, and TSA was performed to determine if the number of participants met the required threshold.

RESULTS

A total of 691 individuals with PCOS from 13 RCTs were evaluated. The meta-analysis indicated that the supplementation of vitamin D led to a notable reduction in the subsequent metabolic parameters: fasting blood glucose[MD=-2.91 mg/dL, 95% CI (-4.78, -1.04) mg/dL, P = 0.002], insulin levels[MD=-1.98 µIU/mL, 95% CI (-3.32, -0.64) µIU/mL, P = 0.004], triglycerides[MD=-11.01 mg/dL, 95% CI (-16.42, -5.61) mg/dL, P < 0.0001], total cholesterol [MD=-11.69 mg/dL, 95% CI (-15.56, -7.82) mg/dL, P < 0.00001], very low-density lipoprotein cholesterol (VLDL-cholesterol) [MD=-2.64 mg/dL, 95% CI (-4.50, -0.79) mg/dL, P = 0.005], and low-density lipoprotein cholesterol (LDL-cholesterol) [MD=-5.85 mg/dL, 95% CI (-10.28, -1.42) mg/dL, P = 0.010]. Nevertheless, the supplementation of vitamin D did not exert a significant impact on high - density lipoprotein cholesterol (HDL - cholesterol) [MD=-0.21 mg/dL, 95% CI (-0.81, 1.22) mg/dL, P = 0.69]. Begg's and Egger's tests suggested a minimal probability of publication bias, and the TSA confirmed that the optimal sample size for major outcomes had been reached, supporting the robustness of the meta-analysis results.

CONCLUSION

Vitamin D supplementation shows significant benefits in improving metabolic parameters in PCOS patients, particularly in reducing fasting blood glucose, insulin, and lipid levels, suggesting a potential role of vitamin D in PCOS management. The long-term outcomes and most effective dose of vitamin D warrant further investigation in future research.

CLINICAL TRIAL NUMBER

Not applicable.

Vitamin D in Reproductive Health Disorders: A Narrative Review Focusing on Infertility, Endometriosis, and Polycystic Ovarian Syndrome

Vitamin D (VD) is a fat-soluble steroid hormone with essential physiological functions beyond calcium and bone metabolism. In recent years, its role in women's reproductive health has gained attention, influencing ovarian function, follicular development, endometrial receptivity, and steroid hormone regulation. VD deficiency has been linked to reproductive disorders such as polycystic ovarian syndrome (PCOS), endometriosis, and infertility. Studies indicate that up to 40-50% of healthy pregnant women have insufficient VD levels, which may contribute to adverse pregnancy outcomes and reduced fertility. With growing evidence connecting VD to reproductive health, this review examines its molecular and endocrine mechanisms in fertility, endometriosis, and PCOS. It explores VD's therapeutic potential and its implications for improving clinical approaches and future research in reproductive medicine. Maintaining adequate VD levels is crucial for ovarian function, immune modulation in reproductive tissues, and overall fertility. Its deficiency is associated with insulin resistance, hormonal imbalances, and inflammatory processes, which contribute to reproductive pathophysiology. Establishing reference values for VD in reproductive medicine is essential for optimizing fertility treatments and improving clinical outcomes. This review synthesizes current research on VD's role in reproductive health and highlights the need for further investigation into its therapeutic applications.

The effect of vitamin D supplementation on markers of insulin resistance in women with polycystic ovarian syndrome: a systematic review

BACKGROUND

Insulin resistance (IR) is a common pathology in women with polycystic ovarian syndrome (PCOS) involved in increased rates of cardiometabolic disease such as diabetes and cardiovascular disease. Low serum vitamin D is often associated with insulin resistance but there is no consensus on whether vitamin D supplementation can ameliorate markers of IR in PCOS.

OBJECTIVES

We assessed evidence on the effects of vitamin D supplementation (≥ 1000 IU/day), without the use of additional supplements or other pharmacological treatments known to affect IR, on markers of IR and glycemic control in women with PCOS.

DESIGN

A systematic search was conducted using PubMed, Medline and Web of Science databases from January 2000 up to November 2023. Randomized controlled trials that assessed the effects of vitamin D supplementation in women with PCOS, on fasting glucose, fasting insulin, glycated haemoglobin (HbA1c) or homeostatic model assessment for insulin resistance (HOMA-IR) were included.

RESULTS

9 studies were identified. Study populations ranged from 28 to 180 participants, with mean ages ranging from 22 to 30 years. Daily vitamin D doses ranged from 1714-12,000 IU. Of the included studies, 3 reported statistically significant reductions in fasting glucose, 2 reported reductions in fasting insulin, 2 reported reductions in HOMA-IR, none reported reductions in HbA1c and 5 reported no differences in any of the relevant outcomes.

CONCLUSIONS

In conclusion, in RCTs of vitamin D supplementation in women with PCOS, the majority of studies do not report statistically significant improvements in fasting glucose, fasting insulin, HbA1c or HOMA-IR. However, as a minority of studies report some statistically significant results, further investigation may be warranted.

REGISTRY

PROSPERO ID: CRD42023486144.

Is there any association between vitamin D status and PCOS disease?

INTRODUCTION

Polycystic ovary syndrome (PCOS) is a common hormonal disorder among women of reproductive age. The current study sought to assess vitamin D status in women with PCOS compared to the control group and to describe the association between vitamin D deficiency and the features of PCOS.

MATERIAL AND METHODOLOGY

A descriptive retrospective study about 176 women of reproductive age was conducted. The sample was divided into two groups: individuals with PCOS (82 women) and healthy individuals without PCOS (94 women). Vitamin D deficiency was defined as a serum concentration less than 10 ng/ml. We used the Statistical Package for the Social Sciences (SPSS), version 21 for all analyses.

RESULTS

In our study, vitamin D deficiency was observed in 40.2% PCOS patients and 24% controls. The 25(OH)D level was lower in PCOS women and the incidence of vitamin D deficiency and insufficiency were significantly higher in comparison with the control group (p < 0.05). Furthermore, PCOS women with insulin resistance or obesity had lower 25(OH)D levels in comparison with PCOS individuals without IR or obesity. Furthermore, a significant correlation was found between homeostatic model assessment for insulin resistance (HOMA-IR)/body mass index (BMI) and vitamin D status.

DISCUSSION AND CONCLUSION

Vitamin D deficiency could be one of the etiological mechanisms of PCOS. In fact, the prevalence of vitamin D deficiency in PCOS women is evident, principally in those with obesity or IR. Also, the serum 25(OH)D level was correlated with parameters of insulin resistance and metabolic syndrome. Therefore, it is proposed that vitamin D supplementation may be beneficial for the management of PCOS patients.

Beyond Hormones: A Systematic Review of the Risk of Cardiovascular Diseases in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a common endocrinopathy among women in the reproductive age group. PCOS is defined by the Rotterdam criteria, which include hyperandrogenism, oligo-anovulation, and polycystic ovaries on ultrasound. The common symptoms are irregular or absent periods, acne, hirsutism, and alopecia androgenica. Increased prevalence of metabolic syndrome is seen among women with PCOS, which increases cardiovascular risk (CVR). Insulin resistance (IR), being most common in PCOS, is often seen in patients with obesity. IR and obesity induce chronic low-grade inflammation in PCOS, increasing various inflammatory markers. Increase in the parameters of tumor necrosis factor-alpha (TNF-alpha), interleukin-1 (IL-1), interleukin-6 (IL-6), C- reactive protein (CRP), plasminogen, endothelin-1, fibrinogen, cystatin-C, fetuin B, vascular endothelial growth factor, and endostatin levels have been documented in the PCOS-affected women. Microbiota alteration is also seen in this demographic, which increases metabolites like trimethylamine-N-oxide (TMAO). TMAO, because of its pro-atherosclerotic activity, is linked to an increase in CVR. In this systematic review, we intended to discover the causes and factors that lead to increased CVR in women diagnosed with PCOS. This systematic review used PubMed, regular keywords, and Google Scholar. The inclusion criteria included the human female population of all ages and literature available in the English language in free full text published between the years 2019 and 2024. The exclusion criteria included research involving animals, works published before 2019, articles written in a language other than English, and articles not publicly available. A total of 89 articles were identified, and 8 final articles were selected after quality assessment.

Available Treatments and Adjunctive Therapies for Polycystic Ovarian Syndrome (PCOS) Patients of Reproductive Age: A Scoping Review

Polycystic ovarian syndrome (PCOS) impacts the health of women worldwide. It is a condition consisting of dysfunctional cystic ovaries resulting in hormonal imbalance. Many women have symptoms such as infertility, increased production of androgens, and insulin resistance. Barriers to effective treatment of PCOS include issues such as delays in diagnosis and inconsistencies in treatment plans among physicians. Despite the current use of available medications to decrease symptomatology, women with PCOS continue to report a decreased quality of life. Using the electronic databases PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and ScienceDirect, a scoping review was conducted on the globally available treatments for PCOS. After applying pre-determined inclusion criteria, 41 studies were included in this scoping review. The literature on the available treatments for PCOS revealed a wide range of therapeutics with evidence of reduction of symptoms and/or improvement in fertility status and pathological processes such as insulin resistance, hormone imbalance, obesity, inflammation, and infertility. Dozens of treatment options for PCOS have been identified, including new medications and modifications to existing treatment regimens. The hormonal drug Fezolinetant demonstrated effective suppression of hyperandrogenism. Drugs used to treat diabetes, such as Liraglutide, were found effective for weight loss. Green cardamom, cinnamon, and other supplements proved effective in treating metabolic dysfunction. Alternative approaches, such as osteopathic manipulative therapy and acupuncture, decreased sympathetic tone and androgen levels. This review provides a succinct overview of PCOS therapies that can be used by those with PCOS and their physicians everywhere. With a better understanding of their options, women with PCOS can become more involved in the decision-making process to improve their health. More research is needed on novel therapies that aim to reduce the primary pathogenesis of PCOS.

The role of vitamin D3 in follicle development

Vitamin D3 plays a crucial role in female reproduction. As research progresses, the mechanisms of action of vitamin D3 on follicular development have been widely discussed. Firstly, key enzymes involved in the synthesis and metabolism of vitamin D3 have been discovered in the ovary, suggesting that vitamin D3 can be synthesized and metabolized locally within the ovary. Additionally, the detection of vitamin D3 receptors (VDR) in follicles suggests that vitamin D3 may exert its effects by binding specifically to these receptors during follicular development. Further research indicates that vitamin D3 promotes follicular growth by enhancing the development of granulosa cells (GCs) and oocytes. Currently, the mechanism of action of vitamin D3 in follicular development is becoming increasingly clear. Vitamin D3 promotes oocyte development by regulating molecules involved in meiotic arrest in oocytes. It also enhances granulosa cell proliferation by stimulating steroid hormone synthesis and cell cycle regulation. Additionally, vitamin D3 exerts anti-inflammatory effects by reducing oxidative stress and advanced glycation end-products (AGEs), mitigating the detrimental effects of inflammation on follicular development. These functions of vitamin D3 have clinical applications, such as in treating polycystic ovary syndrome (PCOS), improving female fertility, and enhancing outcomes in in vitro fertilization (IVF). This review summarizes the research progress on the role and mechanisms of vitamin D3 in follicular development and briefly summarizes its clinical applications.

Effects of vitamin D supplementation on metabolic parameters in women with polycystic ovary syndrome: a randomized controlled trial

OBJECTIVE

The aim of this study was to explore the effects of vitamin D supplementation on metabolic parameters in women with polycystic ovary syndrome (PCOS).

METHODS

A total of 60 PCOS women with vitamin D deficiency or insufficiency were enrolled in this randomized controlled trial. Participants were randomized to vitamin D group (2000 IU/day) or control group. The observational parameters were measured at baseline and after treatment, including body mass index (BMI), waist to hip ratio (WHR), oral glucose tolerance test (OGTT) and insulin release test, and lipid metabolism parameters.

RESULTS

The serum 25(OH)D concentrations at different time points after vitamin D supplementation were significantly higher than that in control group (P < 0.05). The BMI, WHR, insulin concentrations, homeostasis model assessment of insulin resistance (HOMA-IR), triglycerides (TG), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) concentrations in women of Vitamin D group after 12 weeks of treatment were significantly lower than that in women of control group (P < 0.05). The serum insulin concentrations and HOMA-IR at different time points of OGTT, serum TG, TC and LDL-C concentrations in women of vitamin D group (obesity) were significantly lower compared with control group (obesity) (P < 0.05). The BMI, WHR, TG, TC and LDL-C concentration in women of vitamin D group (IR) were significantly lower compared with control group (IR) (P < 0.05). No significant difference was observed in metabolic parameters between vitamin D group (non-obesity) and control group (non-obesity) (P > 0.05), and these differences of metabolic parameters were also not observed between vitamin D group (non-IR) and control group (non-IR) (P > 0.05).

CONCLUSION

Vitamin D supplementation had beneficial effects on metabolic parameters in PCOS women, especially in women with obesity or insulin resistance.

Comparative Management Methods for Adolescents With Polycystic Ovarian Syndrome: A Systemic Review

Polycystic ovarian syndrome (PCOS) is a common endocrinological disorder affecting many adolescents and women of reproductive age worldwide. A diagnosis of PCOS in adolescence relies upon investigating each medical history independently and noting commonly associated symptoms, including obesity, insulin resistance, acne, menstrual abnormalities, and hirsutism. Many researchers are aiming to discover a methodology to help manage the symptoms associated with PCOS, especially in adolescents. This review will investigate management methods possible for adolescents with PCOS. Although the most preferred way to help reduce symptoms is through lifestyle modifications such as vigorous exercise and dietary regimens low in carbohydrates, pharmaceuticals are also offering promising results to adolescents with PCOS. Metformin, oral contraceptives, gonadotropin-releasing hormone (GnRH) antagonists, and other alternatives, including finasteride, eflornithine, fibroblast growth factors (FGFs), and vitamin D, are all shown to help improve insulin sensitivity and regulate menstrual cycles and reduce hirsutism. Epilatory and surgical measurements are also available; however, they are reserved for when all other methods fail and once adulthood or an appropriate age is reached. Although there are many pharmaceuticals available, it is necessary to evaluate each adolescent with PCOS uniquely and prescribe the appropriate pharmacotherapy regarding their symptoms.

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.

Comparison of nutritional supplements in improving glycolipid metabolism and endocrine function in polycystic ovary syndrome: a systematic review and network meta-analysis

Objective

To explore the comparative effectiveness of nutritional supplements in improving glycolipid metabolism and endocrine function in patients with polycystic ovary syndrome (PCOS).

Method

Randomized controlled clinical trials on the effects of nutritional supplements in PCOS patients were searched in PubMed, Embase, Cochrane Library, and Web of Science from their establishments to March 15, 2023. Then, literature screening, data extraction, and network meta-analysis were performed. This study was registered at PROSPERO (registration number CRD 42023441257).

Result

Forty-one articles involving 2,362 patients were included in this study. The network meta-analysis showed that carnitine, inositol, and probiotics reduced body weight and body mass index (BMI) compared to placebo, and carnitine outperformed the other supplements (SUCRAs: 96.04%, 97.73%, respectively). Omega-3 lowered fasting blood glucose (FBG) (SUCRAs: 93.53%), and chromium reduced fasting insulin (FINS) (SUCRAs: 72.90%); both were superior to placebo in improving insulin resistance index (HOMA-IR), and chromium was more effective than Omega-3 (SUCRAs: 79.99%). Selenium was potent in raising the quantitative insulin sensitivity index (QUICKI) (SUCRAs: 87.92%). Coenzyme Q10 was the most effective in reducing triglycerides (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) levels (SUCRAs: 87.71%, 98.78%, and 98.70%, respectively). Chromium and probiotics decreased TG levels, while chromium and vitamin D decreased TC levels. No significant differences were observed in high-density lipoprotein cholesterol (HDL-C), total testosterone (TT), sex-hormone binding globulin (SHBG), and C-reactive protein (CRP) between nutritional supplements and placebo.

Conclusion

Carnitine was relatively effective in reducing body mass, while chromium, Omega-3, and selenium were beneficial for improving glucose metabolism. Meanwhile, coenzyme Q10 was more efficacious for improving lipid metabolism. However, publication bias may exist, and more high-quality clinical randomized controlled trials are needed.

Benefits of using a microencapsulated vitamin D delivery system in women with polycystic ovary syndrome

OBJECTIVE

To compare and assess the efficacy of two vitamin D delivery systems (oil-based and microencapsulated) on 25-hydroxy-vitamin D (25(OH)D) levels, body mass index (BMI) and insulin resistance (IR) in women with established polycystic ovary syndrome (PCOS) and vitamin D deficiency.

MATERIALS AND METHODS

A monocentric, retrospective study was conducted, using the data of 70 female patients, who visited the endocrinology department of the "Dr. Shterev" Hospital, Sofia, Bulgaria between May 2020 and September 2020. The patients were divided into two groups according to the type of vitamin D3 supplementation: either a microencapsulated liposomal form (n=35), or a conventional oil-based form (n=35). The following clinical measures were analysed and compared: BMI, serum levels of 25(OH)D, fasting plasma glucose levels, fasting immunoreactive insulin (IRI), homeostatic model assessment (HOMA) index, levels of antimullerian hormone (AMH) II generation, and testosterone. In all selected patients, these measurements were performed at baseline and 3 months after initiation of vitamin D supplementation.

RESULTS

Significantly increased serum levels of 25(OH)D were observed in patients supplemented with the microencapsulated form of vitamin D3 in the third month from the beginning of therapy, compared with the control group (p=0.003). In the microencapsulated vitamin D group, there was a decrease in IRI serum levels (p=0.023), HOMA-IR (p=0.021), serum AMH (p=0.010) and testosterone levels (p=0.006). The fasting plasma glucose levels did not change significantly.

CONCLUSION

The results of our study show that the patients supplemented with a microencapsulated form of vitamin D3 achieved faster compensation of 25(OH)D levels, which in turn, under equal conditions, led to significant improvement in the metabolic profile, in particular insulin sensitivity.

Polycystic ovary syndrome and thyroid disorder: a comprehensive narrative review of the literature

Background

Published data on the relationship between polycystic ovary syndrome (PCOS) and thyroid dysfunction are sparse and confusing.

Objective

To comprehensively review data available in the literature regarding the relationship between PCOS and the thyroid function, and its abnormalities.

Methods

Nine main areas of interest were identified and analyzed according to the available evidence: 1) Evaluation of thyroid function for PCOS diagnosis; 2) Epidemiology data on thyroid function/disorders in patients with PCOS, and vice versa; 3) Experimental data supporting the relationship between thyroid function/disorders and PCOS; 4) Effects of thyroid function/disorders on PCOS features, and vice versa; 5) Effect of thyroid alterations on the cardiometabolic risk in women with PCOS; 6) Effect of thyroid abnormalities on reproductive outcomes in women with PCOS; 7) Relationship between thyroid function/abnormalities in patients with PCOS who are undergoing fertility treatment; 8) Effect of treatments for thyroid diseases on PCOS; and 9) Effect of treatments for PCOS on thyroid function. An extensive literature search for specific keywords was performed for articles published from 1970 to March 2023 using PubMed and Web of Science. Data were reported in a narrative fashion.

Results

PCOS is a diagnosis of exclusion for which diagnosis is possible only after excluding disorders that mimic the PCOS phenotype, including thyroid dysfunctions. However, the tests and the cutoff values used for this are not specified. Many experimental and clinical data suggest a relationship between perturbations of the thyroid function and PCOS. Direct and unequivocal evidence on the effects of thyroid function/disorders on PCOS features are lacking. High thyroid-stimulating hormone levels and subclinical hypothyroidism may be associated with significant worsening of several intermediate endpoints of cardiometabolic risk in women with PCOS. Thyroid abnormalities may worsen reproductive outcomes, especially in patients undergoing fertility treatment. To date, there are no data demonstrating the efficacy of thyroid medications on fertility and cardiometabolic risk in women with PCOS. Lifestyle modification changes, metformin, and vitamin D seem to improve thyroid function in the general population.

Conclusion

PCOS and thyroid disorders are closely related, and their coexistence may identify patients with a higher reproductive and metabolic risk. Regular screening for thyroid function and thyroid-specific autoantibodies in women with PCOS, particularly before and during pregnancy, is highly recommended.

Women with PCOS who undergo IVF: a comprehensive review of therapeutic strategies for successful outcomes

Polycystic ovarian syndrome (PCOS) is a widespread syndrome that poses unique challenges and constraints to the field of assisted reproductive technology. This condition is the most common cause of anovulation among infertile couples. Debate exists over the best therapeutic course of action when patients with PCOS proceed to IVF. In this review, we evaluate the best-performing and safest methods of IVF preparation, ovarian stimulation, trigger method for maturation of stimulated egg growth, and planning for embryo transfer. Pre-IVF considerations include being aware of individual AMH and vitamin D levels as well as BMI prior to selecting an ovarian stimulation protocol. Numerous supplements such as myo-inositol complement the benefits of lifestyle change and may enhance IVF performance including oocyte yield and pregnancy rate. Concerning stimulation protocols, antagonist cycles with the judicious use of GnRH agonist trigger, pre-treatment with metformin and vitamin D repletion may help mitigate the accompanied risk of ovarian hyperstimulation syndrome (OHSS). Following ovarian stimulation, PCOS patients typically undergo programmed frozen embryo transfer (FET) cycles which are more conducive for women with irregular cycles, but likely carry a higher risk of hypertensive disorders of pregnancy. However, newer stimulated FET protocols using Letrozole may offer improved outcomes. Overall, patients with PCOS require careful individual tailoring of their IVF cycle to achieve optimal results.

1,25-Dihydroxyvitamin D inhibits hepatic diacyglycerol accumulation and ameliorates metabolic dysfunction in polycystic ovary syndrome rat models

Introduction: We aimed to evaluate the influence of 1,25-dihydroxyvitamin D (1,25(OH)2D) on metabolic dysfunction and elucidate its underlying mechanism using a rat model of polycystic ovary syndrome (PCOS).

Methods: Twenty-four Sprague-Dawley rats were randomly divided into four groups: control group (CON, 2 ml/kg of oral 0.5% CMC), 1,25VD group (oral 0.5% CMC and 2.5 ug/kg intraperitoneal 1,25(OH)2D), PCOS group (1 mg/kg oral letrozole), PCOS+1,25VD group (1 mg/kg oral letrozole orally 2.5 ug/kg intraperitoneal 1,25(OH)2D). The treatments were administered for 8 weeks. Body weight, estrus cycle, insulin tolerance, and oral glucose tolerance of the rats in the different groups were assessed. The rats were euthanized at the 8th weeks, and plasma, ovarian, and liver samples were collected and analyzed. The hepatic lipid profile was characterized using HPLC/MRM.

Results: Letrozole-induced PCOS rats exhibited increased weight, insulin resistance, postprandial glucose abnormalities, and dyslipidemia. Compared with the PCOS group rats, the PCOS+1,25VD group rats showed reduced body weight, increased sensitivity to insulin, decreased postprandial glucose, and elevated levels of high-density lipoprotein cholesterol. Moreover, abnormally increased liver concentrations of total diacylglycerol (DG) and DG species in the PCOS rats were reversed by treatment with 1,25(OH)2D. Additionally, hepatic DG and insulin sensitivity were correlated.

Conclusion: 1,25(OH)2D inhibited hepatic DG accumulation and ameliorated metabolic dysfunction in PCOS rat models.

Nutraceuticals and polycystic ovary syndrome: a systematic review of the literature

BackgroundThis study proposes a review of nutraceuticals used in the treatment of typical symptoms of Polycystic Ovary Syndrome (PCOS).The aim is to provide a classification of the most widely used nutraceutical supplements identifying the most effective nutraceuticals on glucose and insulin metabolism, the androgenic hormone profile, fertility, ovulatory capacity, inflammation, and oxidative stress.Material and MethodsWe included randomized controlled trials on PCOS patients undergoing administration of nutraceuticals, in particular vitamin D, vitamin E, probiotics, and inositols. These administrations are variable in terms of dosage, single supplementation, or combined with other compounds, dosage, and duration of the intervention.ResultsThe supplementation of inositols, at the physiologic ratio of 40: 1 of myo- and D-chiro-inositols, resulted to be the most effective in improving the glucose homeostasis and fertility, with a restoration of ovulatory capacity and menstrual regularity. Other nutraceuticals are particularly effective in reducing hyperandrogenism, with promising results demonstrated by the combinations of vitamin D and probiotics, vitamin E and coenzyme Q10, and the enrichment of inositol therapy with group B vitamins. An improvement in the inflammatory status and antioxidant capacity is obtained with the co-supplementation of probiotics and selenium or with vitamin E combined with omega 3.ConclusionsInositol supplementation is effective in the treatment of insulin resistance and fertility. Probiotics reduced hyperandrogenism, inflammatory and oxidative conditions, and resulted more effective when combined with selenium. Although these results proved to be satisfactory, further studies are needed with larger samples and a more homogeneous analysis of the outcomes.

Parameters for Calcium Metabolism in Women with Polycystic Ovary Syndrome Who Undergo Stimulation with Letrozole: A Prospective Cohort Study

For women with polycystic ovarian syndrome (PCOS) and infertility, stimulation with the aromatase-inhibitor letrozole has been recommended as a first-line for ovulation induction. Calcium-associated signaling has also been a component for other ovulation induction and superovulation medications. This study’s aim was to evaluate parameters of calcium metabolism in PCOS women. In a prospective cohort study, 61 anovulatory, infertile PCOS patients who underwent letrozole stimulation were included. Outcome measures were: follicular maturation after letrozole stimulation; parathyroid hormone (PTH); 25-hydroxyvitamin D3 (25OHD3); serum levels of calcium, phosphorus, magnesium, albumin, and total protein. Successful recruitment of a dominant follicle was achieved in 35 patients (57.4%). Women with and without successful follicular development did not differ in serum levels of PTH (38.4 ± 19.7 vs. 39.6 ± 16.2 pg/mL), 25OHD3 (62.5 ± 32.1 vs. 65.4 ± 30.9 nmol/L), calcium (2.36 ± 0.08 vs. 2.37 ± 0.12 mmol/L), or protein (70.2 ± 13.3 vs. 74.0 ± 3.7 g/L), respectively (p > 0.05). However, women who were not responsive to letrozole for ovulation induction demonstrated higher anti-Müllerian hormone (AMH) levels (9.7 ± 4.7 vs. 5.0 ± 3.2 ng/mL, p = 0.005). In conclusion, the success of letrozole stimulation in women with PCOS is independent from calcium metabolism parameters. However, AMH levels seem predictive of medication resistance.

An update on polycystic ovary syndrome: A review of the current state of knowledge in diagnosis, genetic etiology, and emerging treatment options

Polycystic ovary syndrome is the most common endocrine disorder in women of reproductive age, which is still incurable. However, the symptoms can be successfully managed with proper medication and lifestyle interventions. Despite its prevalence, little is known about its etiology. In this review article, the up-to-date diagnostic features and parameters recommended on the grounds of evidence-based data and different guidelines are explored. The ambiguity and insufficiency of data when diagnosing adolescent women have been put under special focus. We look at some of the most recent research done to establish relationships between different gene polymorphisms with polycystic ovary syndrome in various populations along with the underestimated impact of environmental factors like endocrine-disrupting chemicals on the reproductive health of these women. Furthermore, the article concludes with existing treatments options and the scopes for advancement in the near future. Various therapies have been considered as potential treatment through multiple randomized controlled studies, and clinical trials conducted over the years are described in this article. Standard therapies ranging from metformin to newly found alternatives based on vitamin D and gut microbiota could shine some light and guidance toward a permanent cure for this female reproductive health issue in the future.

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.

Natural Molecules in the Management of Polycystic Ovary Syndrome (PCOS): An Analytical Review

Polycystic ovary syndrome (PCOS) is a heterogenous disorder characterized by chronic ovulation dysfunction and hyperandrogenism. It is considered the most common endocrinological disorder, affecting up to 25% of women of reproductive age, and associated with long-term metabolic abnormalities predisposing to cardiovascular risk, such as insulin resistance (IR), dyslipidemia, endothelial dysfunction, and systemic inflammation. PCOS is also characterized by elevated serum levels of luteinizing hormone (LH), causing a condition of hyperandrogenism and a consequent altered ratio between LH and the follicle stimulating hormone (FSH). Over the years, several different approaches have been proposed to alleviate PCOS symptoms. Supplementation with natural molecules such as inositols, resveratrol, flavonoids and flavones, vitamin C, vitamin E and vitamin D, and omega-3 fatty acids may contribute to overcoming PCOS pathological features, including the presence of immature oocyte, IR, hyperandrogenism, oxidative stress and inflammation. This review provides a comprehensive overview of the current knowledge about the efficacy of natural molecule supplementation in the management of PCOS.

A Narrative Review of Current Understanding of the Pathophysiology of Polycystic Ovary Syndrome: Focus on Plausible Relevance of Vitamin D

Polycystic ovarian syndrome (PCOS) is the most prevalent endocrinopathy of reproductive years. Salient features in presentation of patients PCOS include menstrual dysfunction, hyperandrogenism and/or polycystic appearance of ovaries on ultrasound. While the diagnosis of PCOS depends on presence of specified criteria, misdiagnoses are common. Despite years of extensive research, the exact aetiology of PCOS remains largely unknown. In the past decade, apart from insulin resistance and hyperandrogenemia, anti-mullerian hormone (AMH), an important marker of ovarian reserve, and vascular endothelial growth factor (VEGF), a crucial factor in angiogenesis, have been examined as plausible players of causative relevance for PCOS. Vitamin D, a sex-steroid hormone that is universally known for its relevance for skeletal health, has received increasing attention due to growing evidence supporting its pivotal in reproductive physiology and in PCOS. In this review we summarize our current understanding of the mechanisms relevant to the pathophysiology of PCOS and examine the role of vitamin D signalling in this context.

Effects of vitamin D supplementation on metabolic parameters of women with polycystic ovary syndrome: a meta-analysis of randomized controlled trials

OBJECTIVE

The purpose of this meta-analysis was to evaluate the effects of vitamin D supplementation on metabolic parameters of women with polycystic ovary syndrome (PCOS).

METHODS

We performed a literature search of databases and identified randomized controlled trials (RCTs) published prior to December 2019. A meta-analysis was conducted using RevMan 5.3 and Stata 12.0 software. We compared the effects of vitamin D supplementation alone to the administration of placebos on metabolic parameters of PCOS women with vitamin D deficiency.

RESULTS

Ten articles of RCTs were included and analyzed in this meta-analysis, which included a total of 520 PCOS women. Our meta-analysis results showed no significant effects of vitamin D supplementation on BMI (p = .43), systolic blood pressure (p = .05), diastolic blood pressure (p = .87), fasting insulin concentration (p = .86), HOMA-IR (p = .47), HDL-C (p = .76), LDL-C (p = .23) and triglyceride (p = .77). Both low dose vitamin D supplementation (<4000 IU/day) and high dose vitamin D supplementation (≥4000 IU/day) were found to significantly decreased the fasting glucose concentration (p = .01, p = .001, respectively). Vitamin D supplementation significantly decreased total cholesterol concentration (p = .03).

CONCLUSIONS

The results of this meta-analysis suggested that vitamin D supplementation decreases fasting glucose concentration and total cholesterol concentration in PCOS women with vitamin D deficiency.

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.

Adverse Effects of Selected Markers on the Metabolic and Endocrine Profiles of Obese Women With and Without PCOS

The aim of the present study, is to investigate the influence of obesity, with and without polycystic ovarian syndrome (PCOS), on the levels of kisspeptin, vitamin D (Vit D), and vascular endothelial growth factor (VEGF) and to explore the relationship between these parameters and endocrine and metabolic variables. The study group included 126 obese Saudi females. Of these 63 were suffering from PCOS while the rest were normo-ovulatory obese women (non-PCOS obese). In the obese PCOS, VEGF was almost four times as high as in the non-PCOS obese, while kisspeptin and Vit D did not differ. A highly significant elevation was recorded in the waist/hip (WHR), cholesterol, LDL-C, fasting glucose, LH, LH/FSH ratio, estradiol (E2), and testosterone, while hip circumference, leptin, progesterone, and sex hormone binding globulin (SHBG) were lower in the obese PCOS subjects. BMI, HDL-C, ghrelin, insulin, and FSH levels did not differ significantly between the two groups. The obese PCOS had the same level of insulin resistance as the non-PCOS group, as judged by QUICK Index. Correlation studies showed a significant negative correlation between kisspeptin and glucose and LH levels, and a positive correlation with LH/FSH ratio in obese PCOS while in the non-PCOS obese, the kisspeptin correlated positively with glucose, and there was no correlation with LH or LH/FSH. VEGF negatively correlated with FSH and positively with LH/FSH ratio in the non-PCOS obese but this was lost in the obese PCOS. PCOS had no effect on the correlation between Vit D and all studied parameters. Multiple regression analysis showed triglyceride as predictor variable for kisspeptin as a dependent variable, while, leptin is a predictor variable for VEGF as a dependent variable. ROC studies showed the highest sensitivity and specificity for VEGF (AOC=1.00), followed by LH/FSH ratio (AOC=0.979). In conclusion, our study shows that PCOS results in significant elevation of VEGF in obese females, while kisspeptin and Vit D levels are not affected. It also leads to elevation in several of the lipid and hormonal abnormalities in the obese females. In addition, PCOS influences relationship between Kisspeptin and VEGF and some parameters such as glucose, LH or FSH and LH/FSH ratio in obese females, but does not affect Vit D relationship with other parameter.

The Effect of Vitamin D Supplementation on Blood Lipids in Patients with Polycystic Ovary Syndrome: A Meta-Analysis of Randomized Controlled Trials

PURPOSE

Studies have found that vitamin D supplementation may improve blood lipids in patients with polycystic ovary syndrome, but the results are controversial, so this study will further analyze the effect of vitamin D supplementation on blood lipids in patients with polycystic ovary syndrome.

METHODS

PubMed, Embase, Cochrane Library, CNKI, and Wanfang databases were searched up to May 2020, to identify randomized controlled trials of the effect of vitamin D supplementation on blood lipids in patients with polycystic ovary syndrome. The Cochrane risk of bias tool was applied to assess the risk of bias, and RevMan5.3 software was used for statistical analysis.

RESULTS

Ten studies were included in this study, including 543 subjects. The results of the meta-analysis showed that, compared with placebo, vitamin D supplementation can significantly reduce total cholesterol level (WMD = -11.32, 95% CI = [-14.51, -8.41], P < 0.00001), low-density lipoprotein cholesterol level (WMD = -4.83, 95% CI = [-7.52, -2.14], P=0.0004), and triglyceride level (WMD = -8.23, 95% CI = [-13.08, -3.38], P=0.0009, but the effect on high-density lipoprotein cholesterol level is not statistically significant (WMD = -0.32, 95%CI = [-1.24, 0.60], P=0.50).

CONCLUSION

Vitamin D supplementation can significantly reduce total cholesterol, low-density lipoprotein cholesterol, and triglycerides in patients with polycystic ovary syndrome. However, it has no significant effect on high-density lipoprotein cholesterol.

The role of vitamin D in metabolic and reproductive disturbances of polycystic ovary syndrome: A narrative mini-review

Vitamin D is a secosteroid hormone that plays a pivotal role in several metabolic and reproductive pathways in humans. Increasing evidence supports the role of vitamin D deficiency in metabolic disturbances and infertility in women with polycystic ovary syndrome (PCOS). Indeed, supplementation with vitamin D seems to have a beneficial role on insulin resistance and endometrial receptivity. On the other hand, exceedingly high levels of vitamin D appear to play a detrimental role on oocytes development and embryo quality. In the current review, we summarize the available evidence about the topic, aiming to suggest the best supplementation strategy in women with PCOS or, more generally, in those with metabolic disturbances and infertility. Based on the retrieved data, vitamin D seems to have a beneficial role on IR, insulin sensitivity and endometrial receptivity, but high levels and incorrect timing of administration seem to have a detrimental role on oocytes development and embryo quality. Therefore, we encourage a low dose supplementation (400-800 IU/day) particularly in vitamin D deficient women that present metabolic disturbances like PCOS. As far as the reproductive health, we advise vitamin D supplementation in selected populations, only during specific moments of the ovarian cycle, to support the luteal phase. However, ambiguities about dosage and timing of the supplementation still emerge from the clinical studies published to date and further studies are required.

Vitamin D, sport and health: a still unresolved clinical issue

Vitamin D metabolites have a pleiotropic role in human physiology, both in static and dynamic conditions, and a lot of vitamin D-related biological effects could influence physical and sport performances in athletes. Probably due to different factors (e.g., drugs, doping, nutrition, ultraviolet B radiation exposure), in athletes a very high prevalence of vitamin D inadequacy (i.e., deficiency or insufficiency) has been observed. Vitamin D inadequacy in athletes could be associated with specific health risks and to alterations of functional capacities, potentially influencing the fine adjustment of physical performances during training and sport competitions. When risk factors for vitamin D inadequacy exist, a preventive vitamin D supplementation is indicated, and if a vitamin D inadequacy is diagnosed, its supplementation is recommended. Unfortunately, on these issues many concerns remain unresolved. Indeed, it is not clear if athletes should be classified as a special population at increased risk for vitamin D inadequacy; moreover, in comparison to the non-athletic population, it is still not clear if athletes should have different reference ranges and different optimal target levels for serum vitamin D, if they have additional health risks, and if they need different type of supplementations (doses) for prevention and/or replacement therapy. Moreover, in athletes also the abuse of vitamin D supplements for ergogenic purposes raise different ethical and safety concerns. In this review, the main physio-pathological, functional and clinical issues that relate vitamin D to the world of athletes are described.

Influence of vitamin D supplementation on lipid levels in polycystic ovary syndrome patients: a meta-analysis of randomized controlled trials

OBJECTIVE

Observational studies have shown that circulating vitamin D (VitD) deficiency is associated with atherogenic lipid patterns among polycystic ovary syndrome (PCOS) patients. However, interventional studies have shown inconsistent results. The aim of this meta-analysis was to investigate how VitD supplementation influences lipid indices in PCOS patients.

METHODS

The authors searched four electronic databases through August 2019 to identify randomized controlled trials (RCTs) that assessed the effect of VitD intervention on serum lipids among PCOS patients. Mean differences were generated for statistical evaluation.

RESULTS

We included eight studies and performed nine comparisons across 467 participants. VitD supplementation reduced serum triglyceride levels (-11.88 mg/dL; 95% confidence interval [CI]: -17.03 to -6.73), total cholesterol (-9.09 mg/dL; 95% CI: -14.90 to -3.29), low-density lipoprotein cholesterol (-5.22 mg/dL; 95% CI: -10.32 to -0.13), and very-low-density lipoprotein cholesterol (-2.43 mg/dL; 95% CI: -3.69 to -1.17) compared with no VitD supplementation. However, high-density lipoprotein cholesterol levels showed no differences with or without VitD supplementation (-0.39 mg/dL; 95% CI: -1.39 to 0.61).

CONCLUSIONS

VitD supplementation improved serum lipid levels among PCOS patients, but serum high-density lipoprotein cholesterol levels were not changed. VitD intervention might benefit PCOS patients who are at high risk of an atherogenic lipid profile.

Targeting Metabolic Consequences of Insulin Resistance in Polycystic Ovary Syndrome by D-chiro-inositol and Emerging Nutraceuticals: A Focused Review

Polycystic ovary syndrome (PCOS) is a complex disorder associated with ovarian dysfunction, infertility, menstrual irregularity, and hormonal impairments. Over the last decade, several studies have shown that some PCOS women have insulin resistance (InsR) and hyperinsulinemia, apart from being overweight or obese. Therefore, a crucial clinical aspect is that PCOS patients might develop glucose intolerance and type 2 diabetes. Insulin-sensitizing drugs have been used as first-line treatment to improve hyperinsulinemia in women with PCOS. Although reducing PCOS symptoms and signs, several used insulin-sensitizer drugs may induce side effects, which reduces compliance. D-chiro-inositol (DCI), which is a naturally occurring stereoisomer of inositol, has been classified as an insulin-sensitizer and seems to mitigate multiple InsR-related metabolic alterations in PCOS with a safe profile. However, according to a multi-targeted design, the supplementation with DCI can be synergistically integrated by combining other potential insulin-sensitizing drugs and/or nutraceuticals. The literature provides the initial support for using several unexplored nutraceutical interventions that may target relevant metabolic abnormalities associated with InsR in PCOS. With a need to promote interest in clinical research, this review aims to discuss the efficacy of DCI and the role of emerging nutraceuticals for managing InsR in PCOS.

Genetic Components of 25-Hydroxyvitamin D Increase in Three Randomized Controlled Trials

The 25-Hydroxyvitamin D (25[OH)D) serum concentration depends on vitamin D intake, endogenous vitamin D production and genetic factors. The latter have been demonstrated in large genome-wide association studies indicating that single nucleotide polymorphisms (SNPs) in genes related to the vitamin D metabolism are as important for serum 25(OH)D levels as the influence of season. The mechanism on how these SNPs influence serum 25(OH)D levels are still unclear. The aim of the present study was to investigate the genetic effects of ten selected SNPs related to vitamin D metabolism on 25-hydroxyvitamin D increase (∆25(OH)D) after vitamin D supplementation in three randomized controlled trials. Genotypes of SNPs related to vitamin D metabolism were determined in 411 participants with 25(OH)D concentrations < 75 nmol/l receiving 20,000 IU cholecalciferol per week for 8 or 12 weeks after study inclusion. For the vitamin D receptor (VDR) rs10783219 polymorphism, the minor A-allele was associated with lower ∆25(OH)D values in the entire study population (p = 0.022), which was not consistent in all three cohorts when analysed separately. VDR rs10783219 might therefore be a genetic modulator of increasing 25-hydroxyvitamin D concentrations. Considering the wide-spread use of vitamin D supplementation, future large and well-designed randomized controlled trials (RCTs) should investigate the clinical impact of this polymorphism.

Vitamin D Supplementation Ameliorates Metabolic Dysfunction in Patients with PCOS: A SystematicReview of RCTs and Insight into the Underlying Mechanism

OBJECTIVE

Evidence suggests that vitamin D deficiency correlated with metabolic disorders in women with polycystic ovary syndrome (PCOS). We conducted this systematic review and meta-analysis to evaluate the impact of vitamin D supplementation alone on glucose, lipid, and androgen parameters and inflammation biomarkers in women with PCOS.

METHODS

Literature research was conducted in Pubmed, Embase, Web of Science, Clinical Trials, and Cochrane Library to identify relevant randomized controlled trials (RCTs) up to March 2020. The effect of vitamin D supplementation alone on women with PCOS was compared with administration of placebo. The systematic review and meta-analysis protocol was registered in the International Prospective Register of Systematic Reviews (Prospero) as number CRD42020157444.

RESULTS

Thirteen randomized controlled trials with 824 patients in total were included. Serum FPG, fasting insulin, HOMA-IR, and VLDL-C were significantly decreased in the vitamin D group versus placebo. Vitamin D supplementation group also showed a significantly elevated level of QUICKI. No significant impact was seen on serum triglyceride, total-C, LDL-C, HDL-C, total testosterone, DHEAS, SHBG, or hs-CRP. Subgroup analysis demonstrated that oral vitamin D intake had significantly decreased serum triglyceride and total-C level in women with PCOS who have vitamin D deficiency (serum vitamin D < 20 ng/ml).

CONCLUSION

The findings of the present meta-analysis indicate that vitamin D supplementation exerted favorable effects among women with PCOS on glucose metabolism and lipid metabolism, especially in vitamin D deficient women, but had no significant effect on the androgenic profile or inflammation status.

Effects of vitamin D supplementation in women with polycystic ovary syndrome: a review

Increasing evidence supports the contribution of vitamin D deficiency (VDD) in metabolic disturbances among women with polycystic ovary syndrome (PCOS). This review aims to assess the associations between vitamin D levels and metabolic/endocrine dysregulations and to determine the effects of vitamin D supplementation on glucose metabolism, insulin sensitivity, lipid profile, and hormones functionality in PCOS patients. We searched in PubMed human randomized controlled trials (RCTs) published in English between 2016 and 2019 on the effects of vitamin D supplementation on PCOS. Nine studies were included and analyzed. Vitamin D supplementation restored physiological serum 25(OH)D levels in PCOS women in all the studies included. In six studies, it significantly decreased fasting plasma glucose and brought to improvements in insulin resistance (IR) and serum fasting insulin. In addition, four studies reported decreases of serum triglycerides, while discordant data are reported as far as LDL, HDL, and total cholesterol levels. High-doses of vitamin D (4000 IU), compared with low-dose (1000 IU), and placebo, showed beneficial effects on total testosterone, sex hormone-binding globulin (SHBG) and free androgen index (FAI). Vitamin D supplementation at high doses for a period of at least 12 weeks, may lead to improvement in terms of glucose level, insulin sensitivity, hyperlipidemia, and hormonal functionality in PCOS women.

Effects of Vitamin D Supplementation on Body Composition and Metabolic Risk Factors in Men: A Randomized Controlled Trial

Vitamin D might play a role in metabolic processes and obesity. We therefore examined vitamin D effects on metabolic markers and obesity in a randomized controlled trial (RCT). This is a post-hoc analysis of the Graz Vitamin D&TT-RCT, a single-center, double-blind, randomized placebo-controlled trial. We included 200 healthy men with serum 25-hydroxyvitamin D (25(OH) D) levels <75 nmol/L. Subjects received 20,000 IU of vitamin D3/week (n = 100) or placebo (n = 100) for 12 weeks. Outcome measures were metabolic markers, anthropometric measures, and body composition assessed by Dual-energy X-ray absorptiometry. One-hundred and ninety-two men completed the study. We found a significant treatment effect on fasting glucose/fasting insulin ratio (−5.3 (−10.4 to −0.2), p = 0.040), whereas we observed no significant effect on the remaining outcome parameters. In subgroup analyses of men with baseline 25(OH)D levels <50 nmol/L (n = 80), we found a significant effect on waist circumference (1.6 (0.3 to 2.9) cm, p = 0.012), waist-to-hip ratio (0.019 (0.002 to 0.036), p = 0.031), total body fat (0.029 (0.004 to 0.055) %, p = 0.026), and android fat (1.18 (0.11 to 2.26) %, p = 0.010). In middle-aged healthy men, vitamin D treatment had a negative effect on insulin sensitivity. In vitamin D deficient men, vitamin D has an unfavorable effect on central obesity and body composition.

Effects of vitamin D supplementation on bone turnover markers and other bone-related substances in subjects with vitamin D deficiency

In observational studies, vitamin D deficiency is a risk factor for low bone density and future fractures, whereas a causal relation has been difficult to show in randomized controlled trials (RCTs). Similarly, vitamin D deficiency has been associated with increased bone turnover, but RCTs with vitamin D have not shown conclusive effects. This could be due to inclusion of vitamin D sufficient subjects and low vitamin D doses. In the present study 399 subjects with mean baseline serum 25-hydroxyvitamin D (25(OH)D) 34.0 nmol/L completed a four months intervention with vitamin D₃ 20,000 IU per week versus placebo. Mean serum 25(OH)D increased to 89.0 nmol/L in the vitamin D group and decreased slightly in the placebo group. A small, but significant, decrease in the bone formation marker procollagen of type 1 amino-terminal propeptide (P1NP) was seen in the vitamin D group as compared to the placebo group (mean delta P1NP -1.2 pg/mL and 1.5 ng/mL, respectively, P < 0.01). No significant effects were seen on serum carboxyl-terminal telopeptide of type 1 collagen (CTX-1), Dickkopf-1, sclerostin, tumor necrosis factor-alpha, osteoprotegerin, receptor activator of nuclear factor ĸB ligand, or leptin. Subgroup analyses on subjects with low baseline serum 25(OH)D did not yield additional, significant results. In subjects with high baseline serum parathyroid hormone (PTH) > 6.5 pmol/L and post-intervention decrease in PTH, the decrease in P1NP was more pronounced, they also exhibited significantly reduced serum CTX-1 and increased serum sclerostin. In conclusion, supplementation with vitamin D appears to suppress bone turnover, possibly mediated by PTH reduction. Our findings need to be confirmed in even larger cohorts with vitamin D insufficient subjects.

A Randomized, Controlled Trial of Vitamin D Supplementation on Cardiovascular Risk Factors, Hormones, and Liver Markers in Women with Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) increases the risk of metabolic syndrome and non-alcoholic-fatty-liver disease (NAFLD). Vitamin D supplementation may exert positive effects on liver biochemistry in patients with NAFLD; however, its effects on PCOS are unknown. This randomized, double-blind, placebo-controlled study explored the effect of vitamin D supplementation on cardiovascular risk factors (high-sensitivity C-reactive protein (hs-CRP), weight, body mass index (BMI), lipid profile, glucose levels, insulin levels, the homeostatic model assessment-insulin resistance (HOMA-IR), hormones (free androgen index (FAI), testosterone, sex hormone binding globulin (SHBG), and liver markers (alanine aminotransferase (ALT), hyaluronic acid (HA), N-terminal pro-peptide of type III procollagen (PIIINP), tissue inhibitor of metallo-proteinases-1 (TIMP-1), and the enhanced liver fibrosis (ELF) score). Forty women with PCOS were recruited and randomized to vitamin D (3200 IU) or placebo daily for 3 months. All outcomes were measured at baseline and 3 months follow-up (FU). Greater increases in vitamin D levels were shown in the supplementation group (vitamin D, baseline: 25.6 ± 11.4 nmol/L, FU: 90.4 ± 19.5 nmol/L vs. placebo, baseline: 30.9 ± 11.1 nmol/L, FU: 47.6 ± 20.5 nmol/L, p < 0.001). Between groups comparisons (% baseline change) revealed significant differences in ALT (p = 0.042) and a weak effect indicating a greater reduction in the HOMA-IR in the vitamin D group (p = 0.051). No further between group differences were seen in other cardiovascular risk factor, liver markers, or hormones. This study supports beneficial effects of vitamin D supplementation on liver markers and modest improvements in insulin sensitivity in vitamin D deficient women with PCOS.

The Role of Vitamin D in Fertility and during Pregnancy and Lactation: A Review of Clinical Data

Vitamin D deficiency is common and there exists a huge gap between recommended dietary vitamin D intakes and the poor vitamin D supply in the general population. While vitamin D is important for musculoskeletal health, there are accumulating data suggesting that vitamin D may also be important for fertility, pregnancy outcomes and lactation. Significant changes in vitamin D metabolism during pregnancy such as increased production of the “active vitamin D hormone” calcitriol support the important role of vitamin D in this setting. Observational studies show that vitamin D deficiency is a risk marker for reduced fertility and various adverse pregnancy outcomes and is associated with a low vitamin D content of breast milk. Meta-analyses of randomized controlled trials (RCTs) document that physiological vitamin D supplementation during pregnancy is safe and improves vitamin D and calcium status, thereby protecting skeletal health. Although certain RCTs and/or meta-analyses reported some other beneficial effects, it is still not clear whether vitamin D supplementation improves fertility or decreases the risk of adverse pregnancy outcomes such as low birth weight, pre-eclampsia and neonatal mortality, or reduces wheeze/asthma in the infants. Nevertheless, vitamin D supplementation in pregnant women is frequently required to achieve a sufficient vitamin D status as recommended by nutritional vitamin D guidelines. In this review, we provide an overview of systematic reviews, meta-analyses and large trials reporting clinical data on the role of vitamin D for fertility, pregnancy and lactation.