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

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

RESEARCH QUESTION

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

DESIGN

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

RESULTS

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

CONCLUSIONS

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

Vitamin D status, vitamin D receptor polymorphisms, and risk of type 2 diabetes: A prospective cohort study

CONTEXT

Vitamin D status has been associated with risk of type 2 diabetes (T2D), but evidence is scarce regarding whether such relation differs by glycemic status.

OBJECTIVE

To prospectively investigate the association between serum 25-hydroxyvitamin D [25(OH)D] and risk of incident T2D across the glycemic spectrum and the modification effect of genetic variants in vitamin D receptor (VDR).

METHODS

This prospective study included 379,699 participants without T2D at baseline from the UK Biobank. Analyses were performed according to glycemic status and HbA1c levels. Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% CIs.

RESULTS

During a median of 14.1 years of follow-up, 6,315 participants with normoglycemia and 9,085 prediabetes patients developed T2D. Compared to individuals with 25(OH)D <25 nmol/L, the multivariable-adjusted hazard ratios (95% CIs) of incident T2D for those with 25(OH)D ≥75 nmol/L was 0.62 (0.56, 0.70) among the normoglycemia and 0.64 (0.58, 0.70) among the prediabetes. A significant interaction was observed between 25(OH)D and VDR polymorphisms among participants with prediabetes (Pinteraction=0.017), whereby the reduced HR of T2D associated with higher 25(OH)D was more prominent in those carrying T allele of rs1544410. Triglycerides levels mediated 26% and 34% of the association between serum 25(OH)D and incident T2D among participants with normoglycemia and prediabetes.

CONCLUSIONS

Higher serum 25(OH)D concentrations were associated with lower T2D risk across the glycemic spectrum below the threshold for diabetes, and the relations in prediabetes were modified by VDR polymorphisms. Improving lipid profile, mainly triglycerides, accounted for part of the favorable associations.

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.

Efficacy of antioxidant supplementation in improving endocrine, hormonal, inflammatory, and metabolic statuses of PCOS: a meta-analysis and systematic review

Background and aim: A large number of recent studies have reported on the use of antioxidants in patients with polycystic ovary syndrome (PCOS). This study aimed to evaluate the antioxidant effects on PCOS. Methods: We searched PubMed, Embase, Web of Science, and The Cochrane Library to identify randomized controlled trials investigating the use of antioxidants in treating PCOS. Statistical analysis was performed using Review Manager 5.4. Stata17.0 software was used to conduct sensitivity analyses. Results: This meta-analysis included 49 articles and 62 studies. The sample comprised 1657 patients with PCOS from the antioxidant group and 1619 with PCOS from the placebo group. The meta-analysis revealed that the fasting blood glucose levels [standardized mean difference (SMD): -0.31, 95% confidence interval (CI): -0.39 to -0.22, P < 0.00001], the homeostatic model assessment of insulin resistance (SMD: -0.68, 95% CI: -0.87 to -0.50], P < 0.00001), and insulin levels (SMD: -0.68, 95% CI: -0.79 to -0.58, P < 0.00001) were significantly lower in patients with PCOS taking antioxidants than those in the placebo group. Further, total cholesterol levels (SMD: -0.38, 95% CI: -0.56 to -0.20, P < 0.001), low-density lipoprotein cholesterol levels (SMD: -0.24, 95% CI: -0.37 to -0.10, P = 0.0008), and very low-density lipoprotein levels (SMD: -0.53, 95% CI: -0.65 to -0.41, P < 0.00001) were lower in patients with PCOS taking antioxidant supplements compared with the placebo group. Total testosterone (TT) level (SMD: -0.78, 95% CI: -1.15 to -0.42, P < 0.0001), dehydroepiandrosterone level (SMD: -0.42, 95% CI: -0.58 to -0.25, P < 0.00001), and mean standard deviation modified Ferriman-Gallway (MF-G scores) (SMD: -0.63, 95% CI: -0.98 to -0.28, P = 0.0004) were lower in patients taking antioxidant supplements. C-reactive protein (CRP) levels (SMD: -0.48, 95% CI: -0.63 to -0.34, P < 0.000001), body mass index [mean difference (MD): -0.27, 95% CI: -0.50 to -0.03, P = 0.03], weight (MD: -0.73, 95% CI: -1.35 to -0.11, P = 0.02), and diastolic blood pressure (MD: -3.78, 95% CI: -6.30 to -1.26, P = 0.003) were significantly lower. Moreover, the levels of sex hormone-binding protein (SMD: 0.23, 95% CI: 0.07-0.38, P = 0.004), high-density lipoprotein cholesterol (SMD: 0.11, 95% CI: 0.01-0.20, P = 0.03), total antioxidant capacity (SMD: 0.59, 95% CI: 0.31-0.87, P < 0.0001), and quantitative insulin sensitivity index (SMD: 0.01, 95% CI: 0.01-0.02, P < 0.00001) were higher in patients with PCOS who took antioxidant supplements compared with the placebo group. Antioxidant supplements did not affect other analyzed parameters in these patients, including follicle-stimulating hormone, free androgen index, nitric oxide, glutathione, malondialdehyde, and diastolic blood pressure. Conclusions: Antioxidants are beneficial in treating PCOS. Our study might provide a new treatment strategy for patients with clinical PCOS. We hope that more high-quality studies evaluating the effects of antioxidants on patients with PCOS will be conducted in the future. Registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42023448088.

Association of insulin resistance with polycystic ovary syndrome phenotypes and patients' characteristics: a cross-sectional study in Iran

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women. This disorder affects 6-15% of women of childbearing age worldwide. It is diagnosed with hyperandrogenism, polycystic ovaries, and chronic anovulation with insulin resistance. This study aimed to assess the prevalence of insulin resistance (IR) in 4 phenotypes of PCOS, and its relationship with demographic, clinical, and paraclinical individual characteristics in a sample of Iranian PCOS patients.

METHODS

This particular cross-sectional investigation involved 160 female participants, aged between 18 and 45 years, who were receiving care at gynecology clinics in Urmia, northwestern Iran. All the participants had been diagnosed with PCOS and were categorized into one of four phenotypes. All the participants underwent clinical evaluations, paraclinical assessments, and ultrasound scans. IR was defined as HOMA-IR > 2.5. The statistical significance level was 0.05.

RESULTS

Among the 160 participants, the prevalences of the 4 phenotypes were: A: 83 (51.9%), B: 37 (23.1%), C: 21 (13.1%), and D: 19 (11.9%). IR was detected in 119 participants (74.4%); its rate was significantly different between the 4 phenotypes (p-value: 0.008) as A: 62 (74.7%), B: 34 (91.9%), C: 12 (57.1%), D: 11 (57.9%). Linear and logistic regression analyses were performed to control confounding factors. In linear regression, PCOS phenotype, classic phenotype (A&B), economic status, and Hb levels were significantly related to HOMA-IR; in logistic regression Hb levels, exercise, economic status, and PCOS phenotypes were significantly associated with insulin resistance.

CONCLUSIONS

The most prevalent PCOS phenotype in this study was A. PCOS phenotypes were significantly related to insulin resistance and HOMA-IR, with the highest levels of insulin resistance and HOMA-IR observed in phenotype B. Determining the phenotype of PCOS may be helpful for better management of PCOS and its associated complications. However, further investigations are recommended in this regard.

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.

The Relationship between Self-Reported Sitting Time and Vitamin D Levels in Middle-Aged and Elderly Taiwanese Population: A Community-Based Cross-Sectional Study

(1) Background: Many studies have revealed a relationship between serum 25-hydroxy vitamin D and physical activity. This study aimed to investigate the relationship between self-reported sitting time and serum 25-hydroxy vitamin D levels in middle-aged and elderly adults in Taiwan. (2) Methods: A total of 396 people were enrolled in our study during a community health examination in Taiwan in 2019. We grouped participants from low to high according to their tertile of serum 25-hydroxy vitamin D levels, using the following categories: deficiency, insufficiency, and sufficiency. Parameters including self-reported sitting time were analyzed between each group. Pearson correlation coefficients were calculated to explore the relationships of serum 25-hydroxy vitamin D levels with age-adjusted risk factors. A scatter plot demonstrated the relationship between serum 25-hydroxy vitamin D levels and self-reported sitting time. The association between serum 25-hydroxy vitamin D levels and self-reported sitting time was assessed by multivariate linear regression with adjustment for age, sex, waist circumference, low-density lipoprotein, triglycerides, and smoking and drinking status. (3) Results: We analyzed the data from 396 participants. A total of 41.4% of participants were male, and the average age of all participants was 64.91 (±8.80) years. The participants in the high serum 25-hydroxy vitamin D group were more likely to have shorter self-reported sitting time. Serum 25-hydroxy vitamin D was negatively correlated (Pearson's r) with self-reported sitting time, even after adjustment for age. According to the results of multivariate linear regression, vitamin D levels showed a negative association with self-reported sitting time (β = -0.131, p = 0.006) after adjustment for age, sex, waist circumference, low-density lipoprotein, triglycerides, and smoking and drinking status. (4) Conclusions: According to our research, self-reported sitting time was inversely correlated with serum 25-hydroxy vitamin D in middle-aged and elderly people in Taiwan. Meanwhile, longer self-reported sitting time can be an independent risk factor for lower serum 25-hydroxy vitamin D levels.

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.

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.

Combined Effect of Omega-3 Fatty Acid and Vitamin D 3 on Oxidized LDL-C and Non-HDL-C Levels in People With Vitamin D Deficiency: A Randomized Controlled Trial

ABSTRACT

The present randomized clinical trial (RCT) was conducted on Jordanian participants with vitamin D deficiency (VDD) with no other medical conditions, to evaluate the combined effect of 1,25-dihydroxy vitamin D 3 (Vit.D 3 ) and omega-3 fatty acid (n-3FA) supplements (D+) on oxidized low-density lipoprotein (Ox-LDL) and non-high-density lipoprotein cholesterol (non-HDL-C) levels as common predictors of cardiovascular diseases (CVDs). Participants were randomized into 4 groups as follows: a control group (C) that received no supplementations, a Vit.D 3 group that received 50,000 IU of Vit.D 3 every week, an n-3FA group that received 300 mg of omega-3 fatty acid every day, and a D+ group that received a combination of both supplements, with the same dosage administered by the previous groups but with a 4-6-hour time interval between Vit.D 3 and n-3FA administration to avoid any possible interaction. All supplementations were administered orally for 8 weeks. Forty-seven participants were allocated to each group. Twenty-six in the control group, 37 participants in the Vit.D 3 group, 37 participants in the n-3FA group, and 46 participants in the D+ group completed the study to the end. The D+ supplementations significantly increased non-HDL-C (118.99 ± 60.98 to 155.26 ± 43.36 mg/dL, P << 0.05) but decreased Ox-LDL-C levels (69.29 ± 37.69 to 52.81 ± 17.30 pg/mL, P = 0.03). The stepwise regression showed that the serum LDL-C level was the main independent variable involved in the elevation of non-HDL levels (R 2 = 0.837) observed at the end of the trial in the D+ group. The groups that were supplemented with either Vit.D 3 alone or n-3FA alone had an insignificant decrease in the level of Ox-LDL-C. In conclusion, despite the observed hyperlipidemic effect, the combination treatment is recommended by the research team because the decrease in Ox-LDL may offset the hyperlipidemic effect.

Comparative analysis of biochemical, hormonal, and mineral compositions of preovulatory and cystic ovarian follicles in buffalo during the non-breeding season

This study is a comparative analysis of the biochemical, hormonal, and mineral compositions of follicular fluid in preovulatory and cystic follicles of water buffalo (Bubalus bubalis). In total, reproductive tracts from 215 buffalo along with intact ovaries were collected randomly from an abattoir. The incidence of cystic conditions found in this study was 3.72% (8/215), involving the right ovary in 62.5% of instances and the left ovary in 37.5% of instances during the non-breeding season. Follicular fluid was aspirated from preovulatory follicles (12-15 mm diameter, oestrogen-active, follicular phase or stage IV corpus luteum on one of the two ovaries, n = 10) and cystic follicles (at least 20 mm diameter, no corpus luteum on any one of the two ovaries, n = 8). The follicular fluid samples were assayed for biochemical components (uric acid, creatinine, blood urea nitrogen, cholesterol, total protein, glucose, ascorbic acid, and alkaline phosphatase), hormones (progesterone, estradiol, and insulin), and minerals (calcium, magnesium, phosphorus, copper, zinc, and cobalt). Cystic follicles had greater (P < 0.05) concentrations of creatinine, blood urea nitrogen, cholesterol, progesterone, copper, zinc, and cobalt, and lesser (P < 0.05) concentrations of uric acid, glucose, ascorbic acid, estradiol, insulin, calcium, magnesium, and phosphorus compared with preovulatory follicles. These results indicated the marked differences in follicular fluid composition between preovulatory and cystic follicles in buffalo. Some of the changes were indicative of oxidative stress and disturbed steroidogenesis, two important mechanisms shown to be associated with cystic ovarian disease in various species. Further studies are warranted to investigate whether these differences are directly or indirectly involved in the formation of cystic follicles or are mere manifestations of the condition.

Vitamin D supplementation in the treatment of polycystic ovary syndrome: A meta-analysis of randomized controlled trials

Background

Vitamin D level is closely associated with the development of polycystic ovary syndrome (PCOS). We aimed to systematically evaluate the effects of vitamin D supplementation on patients with PCOS, to provide reliable evidence to the clinical treatment of PCOS.

Methods

We searched PubMed, Medline, EMbase, Cochrane Library, Web of Science, WanFang, China national knowledge infrastructure(CNKI) and Weipu databases for randomized controlled trials (RCTs) on vitamin D supplementation for the treatment of PCOS. Two reviewers independently screened literature, extracted data and evaluated the risk of bias of included RCTs. RevMan 5.3 software was used for meta-analysis.

Results

13 RCTs with 840 PCOS patients were included finally. Meta-analyses indicated that vitamin D supplementation increase the serum vitamin D level[mean difference(MD) = 17.81, 95% confidence interval(CI) (10.65, 24.97)] and endometrial thickness [MD = 1.78, 95%CI (0.49, 3.06), P = 0.007], reduce the serum hs-CRP [MD = -0.54, 95%CI (-1.00, -0.08)], parathyroid hormone[MD = -14.76, 95%CI (-28.32, -1.19)], total cholesterol[MD = -12.00, 95%CI (-18.36, -5.56)] and total testosterone level [MD = -0.17, 95%CI (-0.29, -0.05)] (all p < 0.05). No significant differences in the SHBG level [MD = 1.33, 95%CI (-2.70, 5.36)] and mF-G score [MD = 0.04, 95%CI (-0.79, 0.86)] between vitamin D and control group were found (all p > 0.05). Egger's tests showed that there were no publication biases in every synthesized result (all P > 0.05).

Conclusion

Vitamin D may be helpful to improve the endocrine and metabolism-related indexes in patients with PCOS. More high-quality studies with larger sample size are warranted to further evaluate the role of vitamin D supplementation in patients with PCOS.

Overview of gene expression techniques with an emphasis on vitamin D related studies

Each cell controls when and how its genes must be expressed for proper function. Every function in a cell is driven by signaling molecules through various regulatory cascades. Different cells in a multicellular organism may express very different sets of genes, even though they contain the same DNA. The set of genes expressed in a cell determines the set of proteins and functional RNAs it contains, giving it its unique properties. Malfunction in gene expression harms the cell and can lead to the development of various disease conditions. The use of rapid high-throughput gene expression profiling unravels the complexity of human disease at various levels. Peripheral blood mononuclear cells (PBMC) have been used frequently to understand gene expression homeostasis in various disease conditions. However, more studies are required to validate whether PBMC gene expression patterns accurately reflect the expression of other cells or tissues. Vitamin D, which is responsible for a multitude of health consequences, is also an immune modulatory hormone with major biological activities in the innate and adaptive immune systems. Vitamin D exerts its diverse biological effects in target tissues by regulating gene expression and its deficiency, is recognized as a public health problem worldwide. Understanding the genetic factors that affect vitamin D has the potential benefit that it will make it easier to identify individuals who require supplementation. Different technological advances in gene expression can be used to identify and assess the severity of disease and aid in the development of novel therapeutic interventions. This review focuses on different gene expression approaches and various clinical studies of vitamin D to investigate the role of gene expression in identifying the molecular signature of the disease.

Preconception Vitamin D Level and In Vitro Fertilization: Pregnancy Outcome

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Omics as a Tool to Help Determine the Effectiveness of Supplements

There has been considerable interest in dietary supplements in the last two decades. Companies are releasing new specifics at an alarming pace, while dietary supplements are one of the less-studied substances released for public consumption. However, access to state-of-the-art and high-throughput techniques, such as the ones used in omics, make it possible to check the impact of a substance on human transcriptome or proteome and provide answers to whether its use is reasonable and beneficial. In this review, the main domains of omics are briefly introduced. The review focuses on the three most widely used omics techniques: NGS, LC-MS, NMR, and their usefulness in studying dietary supplements. Examples of studies are described for some of the most commonly supplemented substances, such as vitamins: D, E, A, and plant extracts: resveratrol, green tea, ginseng, and curcumin extract. Techniques used in omics have proven to be useful in studying dietary supplements. NGS techniques are helpful in identifying pathways that change upon supplementation and determining polymorphisms or conditions that qualify for the necessity of a given supplementation. LC-MS techniques are used to establish the serum content of supplemented a compound and its effects on metabolites. Both LC-MS and NMR help establish the actual composition of a compound, its primary and secondary metabolites, and its potential toxicity. Moreover, NMR techniques determine what conditions affect the effectiveness of supplementation.

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.

Female infertility and diet, is there a role for a personalized nutritional approach in assisted reproductive technologies? A Narrative Review

Female infertility is a major public health concern and a global challenge. It is a disorder of the reproductive system, defined as the inability to achieve a clinical pregnancy. Nutrition and other environmental factors are found to impact reproductive health in women as well as the outcome of assisted reproductive technologies (ART). Dietary factors, such as polyunsaturated fatty acids (PUFA), fiber as well as the intake of Mediterranean diet appear to exert beneficial effects on female reproductive outcomes. The exact mechanisms associating diet to female fertility are yet to be identified, although genomic, epigenomic, and microbial pathways may be implicated. This review aims to summarize the current knowledge on the impact of dietary components on female reproduction and ART outcomes, and to discuss the relevant interplay of diet with genome, epigenome and microbial composition.

Vitamin D and calcium, together and separately, play roles in female reproductive performance

Vitamin D (VD) deficiency reduces the chances of successful fertilization; however, it remains to be validated whether this effect is dependent or not on calcium. To address this question, we generated several situation using a mouse model in which VD content was either increased or decreased in a normo or hypocalcemia context. After the measurement of serum 25-hydroxyvitamin D₂, calcium and phosphorus levels, an analysis was carried out in terms of oocytes maturation as well as reproductive performance. VD overdose, despite the fact that it resulted in an increased number of mature oocytes, reduced developmental competence and offspring survival. VD deficiency (VDD), on the contrary, reduced the number and percentage of mature oocytes, blastocyst rate, as well as fertility rate and offspring survival. Hypo-calcemia when VD levels were normal, had a similar effect than VDD. The effects of VDD were reversed by a diet that corrected calcium level. Therefore, both VD overdose (in a context of normal calcium level) VD deficiency as well as hypo-calcemia have an effect on female reproductive function. In conclusion, although closely related, VD and calcium act in part independently of each other in defining the “optimum” for female reproductive performance.

Dietary Supplements for Female Infertility: A Critical Review of Their Composition

Infertility is the condition of about 15% of couples that cannot get a conception after one year of unprotected sexual intercourse. In females, the reduced reproductive capacity underlies the most varied causes. Dietary supplements (DS) might be used to improve the pregnancy rate and a wide range of DS are proposed today to support female fertility. Although many authors demonstrated the positive effect of some of these products, the real efficacy of this approach is still debated. In order to evaluate the potential efficacy of DS for female infertility, we analysed the products marketed in Italy, using an original approach. A review of literature was performed to evaluate the effect of nutraceuticals on various female reproductive outcomes and to detect the minimal effective daily dose (mED) able to improve at least one of these. Thereafter, we conceived a formula to classify the expected efficacy of each DS. Each DS was scored and included into three classes of expected efficacy: higher, lower, and none. Ten out of 24 supplements (41.7%) resulted in the higher and 8 (34.3%) in the lower efficacy group, the remaining 6 DS (25.0%) were expected to have no efficacy. DS marketed in Italy are usually blends of many substances that are frequently employed at a negligible dose or without any evidence of efficacy. These findings raise serious doubt about the potential effectiveness of most commercial DS for female infertility.

Correlations among anti-Müllerian hormone levels, body mass index and lipid profile in reproductive-aged women: The Korea Nurses' Health Study

Aim

This study aimed to evaluate the correlations among anti‐Müllerian hormone levels, body mass index and lipid profile in female nurses of reproductive age.

Design

This is a descriptive cross‐sectional study that used data from the Korea Nurses' Health Study, based on Nurses' Health Study 3 in the United States.

Methods

Participants included 448 female nurses of reproductive age. They provided details about their work experience, shift work, body mass index and history of polycystic ovary syndrome. Serum anti‐Müllerian hormone levels and lipid profile were measured using blood samples. Statistical analysis included quantile regression analysis using STATA 13.0. Data were collected between November 2016 and March 2017 from Module 5 of the Korean Nurses' Health Study.

Results

Approximately 12% of the participants were underweight, and roughly one‐tenth were either overweight or obese. Although linear regression showed no relationship between anti‐Müllerian hormone levels and body mass index, quantile regression showed that body mass index, total cholesterol levels and low‐density lipoprotein levels were negatively correlated with anti‐Müllerian hormone levels at the lower tails of the dependent variable. Meanwhile, high‐density lipoprotein levels were positively correlated with anti‐Müllerian hormone at the higher percentiles of anti‐Müllerian hormone levels.

Conclusion

These findings suggest the possibility that changes in the lipid profile may influence anti‐Müllerian hormone levels in women with diminished ovarian function, rather than obesity itself.

Transcriptional Insights into Key Genes and Pathways Underlying Muscovy Duck Subcutaneous Fat Deposition at Different Developmental Stages

Simple Summary

Subcutaneous fat is an important factor affecting the meat quality and feed conversion rate of waterfowl. The current study compared the transcriptome data of Muscovy duck subcutaneous fat among three developmental stages, aiming at exploring the key regulatory genes for subcutaneous fat deposition. The results generated abundant candidate genes and pathways involving in subcutaneous fat deposition in Muscovy duck. This study provides an important reference for revealing the developmental mechanisms of subcutaneous fat in duck.

Abstract

Subcutaneous fat is a crucial trait for waterfowl, largely associated with meat quality and feed conversion rate. In this study, RNA-seq was used to identify differentially expressed genes of subcutaneous adipose tissue among three developmental stages (12, 35, and 66 weeks) in Muscovy duck. A total of 138 and 129 differentially expressed genes (DEGs) were identified between 35 and 12 weeks (wk), and 66 and 35 wk, respectively. Compared with 12 wk, subcutaneous fat tissue at 35 wk upregulated several genes related to cholesterol biosynthesis and fatty acid biosynthesis, including HSD17B7 and MSMO1, while it downregulated fatty acid beta-oxidation related genes, including ACOX1 and ACSL1. Notably, most of the DEGs (92.2%) were downregulated in 66 wk compared with 35 wk, consistent with the slower metabolism of aging duck. Protein network interaction and function analyses revealed GC, AHSG, FGG, and FGA were the key genes for duck subcutaneous fat from adult to old age. Additionally, the PPAR signaling pathway, commonly enriched between the two comparisons, might be the key pathway contributing to subcutaneous fat metabolism among differential developmental stages in Muscovy duck. These results provide several candidate genes and pathways potentially involved in duck subcutaneous fat deposition, expanding our understanding of the molecular mechanisms underlying subcutaneous fat deposition during development.

Does vitamin D supplementation improve ovarian reserve in women with diminished ovarian reserve and vitamin D deficiency: a before-and-after intervention study

OBJECTIVE

Evaluation of vitamin D supplementation on ovarian reserve in women with diminished ovarian reserve and vitamin D deficiency.

METHODS

The study is a before-and-after intervention study that was performed on women with diminished ovarian reserve referred to Shahid Mofteh Clinic in Yasuj, Iran. Eligible women were prescribed vitamin D tablets at a dose of 50,000 units weekly for up to 3 months. Serum levels of vitamin D and AMH were evaluated at the end of 3 months. Significance level was also considered P ≤ 0.05.

RESULTS

Our results have been showed there was a statistically significant difference in vitamin D levels of participants before [12.1(6.5)] and after [26(9.15)] the intervention (P < 0.001). Moreover, there was a statistically significant difference in serum AMH levels of participants before [0.50(0.44)] and after [0.79(0.15)] the intervention (P=0.02 ).

CONCLUSION

In conclusion, the results of the current study support a possible favorable effect of vitamin D on increase AMH expression by acting on the AMH gene promoter. Therefore, it is possible that vitamin D increases AMH levels without changing the antral follicle count/ovarian reserve.

The association between the levels of anti-Müllerian hormone (AMH) and dietary intake in Iranian women

PURPOSE

This paper aimed to assess the association between AMH with dietary intake of adult women referred to the infertility clinic of Al-Zahra Hospital in Rasht, Iran.

METHODS

This cross-sectional study was performed on 234 adult women referred to the infertility clinic of Al-Zahra Hospital, Rasht, Iran. The participants were categorized into two groups based on their AMH levels. Participants' data on lifestyle and anthropometry as well as blood samples were collected. Dietary intakes were assessed by a validated food frequency questionnaire (FFQ).

RESULTS

Serum AMH concentration was negatively associated with the intake of fast foods (P = 0.002) and saturated fats (P = 0.040). These associations remained significant after adjustments for age, rural or urban location, and education. Additional adjustments for body mass index (BMI) and physical activity did not change the results. The results remained significant after further adjustments for menstrual age, menstrual pattern, and oral contraceptive pills.

CONCLUSION

Fast foods and saturated fats were significantly associated with lower AMH concentrations and modifying the amount of these dietary components may be an important strategy for increasing the reservation of ovaries in women. Future longitudinal studies are warranted to confirm these findings and to identify the underlying mechanisms.

Effects of Vitamin D Supplementation on Cardiovascular and Glycemic Biomarkers

Background Experimental and observational studies have suggested a link between vitamin D and cardiovascular and metabolic disease, but this has not been confirmed in randomized controlled trials. We sought to determine whether vitamin D supplementation reduces biomarkers of insulin resistance, inflammation, neurohormonal activation, and lipids. Methods and Results This was a prespecified, secondary analysis of the DAYLIGHT (Vitamin D Therapy in Individuals at High Risk of Hypertension) randomized controlled trial. We measured circulating homeostatic model assessment of insulin resistance, hs-CRP (high-sensitivity C-reactive protein), N-terminal pro-B-type natriuretic peptide, renin, aldosterone, and lipids at baseline and at 6 months in 289 individuals with low vitamin D status (25-hydroxyvitamin-D [25-OH-D] ≤25 ng/mL) receiving low-dose (400 IU/d) versus high-dose (4000 IU/d) vitamin D3 for 6 months. A meta-analysis of randomized controlled trials reporting biomarker changes after vitamin D supplementation was then performed. Levels of 25-OH-D increased in the high-dose relative to the low-dose vitamin D group (+15.5 versus +4.6 ng/mL, P<0.001). Changes in biomarkers of glycemia, inflammation, and neurohormonal activation did not differ by dose. Lipids did not differ between groups, other than triglycerides, which increased in the high-dose compared with the low-dose group (+11.3 versus -6.2 mg/dL, P<0.001). The meta-analysis showed potential modest decreases in homeostatic model assessment of insulin resistance and hs-CRP, but no changes in low-density lipoprotein, after vitamin D supplementation compared with control groups. Conclusions In the DAYLIGHT randomized controlled trial, high-dose vitamin D supplementation did not improve biomarkers of glycemia, inflammation, neurohormonal activation, or lipids. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT01240512.

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.

Polycystic Ovary Syndrome: Pathophysiology, Presentation and Treatment a Mini-Review Article

Polycystic ovary syndrome (PCOS) is a common heterogeneous disorder which is known as syndrome. The term ‘syndrome’ refers to a collection of clinical features or a phenotype. The specific features of the PCOS phenotype include clinical signs of androgen excess, elevated serum androgen concentrations, irregular menses, and infertility. It is common heterogenous disorder which affects women with different clinical presentations. In the basis of this disease is hormonal imbalance, such as insulin resistance and hyperinsulinemia. This review was based on searching all the available literature in the next databases: Pubmed, ClinicalTrials, Embase, Medline Complete, Web of Science, Cochrane Library, the Chinese Science and Technology Periodical Database (VIP), WanFang Database (Chinese Ministry of Science & Technology). The search terms included hormonal and metabolic aspects, therapy of PCOS, polycystic ovary syndrome, PCOS.We included only randomized clinical intervention trials in young women published in last five years and included 12 articles in our review analysis. More research is needed to clarify the complex pathophysiology of PCOS. No single test is currently available for its diagnosis. Additionally, once diagnosis is established, the options for treatment are of limited number and effectiveness because they target only the symptoms of PCOS. Finally, patients with PCOS have higher rates of metabolic complications, such as cardiovascular disease, but their impact on mortality is not clear. Therefore, more prospective epidemiologic studies on the topic are necessary.

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.

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.

Tailoring treatment for PCOS phenotypes

Introduction: Polycystic ovary syndrome (PCOS) is one of the most common endocrinopathies in reproductive-aged women. Hyperandrogenism, polycystic ovaries, chronic anovulation, and metabolic aberrations are its common features. The treatment approach focuses on the main aberrations, which characterize the different phenotypes. Areas covered: Management strategies targeting the metabolic phenotype include lifestyle modifications for weight loss and improvement of dietary habits, as well as medication, such as insulin-sensitizers. The treatment of hyperandrogenic phenotype includes cosmetic procedures and the combined oral contraceptives with or without antiandrogens. The therapeutic approach to reproductive phenotype includes diet and lifestyle modifications, clomiphene citrate, and aromatase inhibitors. Alternative treatments include dietary supplements, herbs, resveratrol, myo-inositol, and acupuncture. Expert opinion: New studies have shown that higher anti-Müllerian hormone levels, gut microbiome composition, and plasma metabolomics are new parameters that are related to the most severe phenotypes. The clinical phenotypes can change over the lifespan with weight gain and can coexist in the same individual. Individualized treatment remains the main approach but grouping the phenotypes and following therapeutic recommendations may prove to be also clinically appropriate.

Serum Vitamin D Affected Type 2 Diabetes though Altering Lipid Profile and Modified the Effects of Testosterone on Diabetes Status

Numerous studies have investigated the associations between serum vitamin D or testosterone and diabetes; however, inconsistencies are observed. Whether there is an interaction between vitamin D and testosterone and whether the lipid profile (total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C)) mediates the association between vitamin D and diabetes is unclear. To investigate the effect of vitamin D and testosterone on impaired fasting glucose (IFG) or type 2 diabetes mellitus (T2DM), 2659 participants from the Henan Rural Cohort were included in the case-control study. Generalized linear models were utilized to estimate associations of vitamin D with IFG or T2DM and interactive effects of vitamin D and testosterone on IFG or T2DM. Principal component analysis (PCA) and mediation analysis were used to estimate whether the lipid profile mediated the association of vitamin D with IFG or T2DM. Serum 25(OH)D₃, 25(OH)D₂, and total 25(OH)D levels were negatively correlated with IFG (odds ratios (ORs) (95% confidence intervals (CIs)): 0.99 (0.97, 1.00), 0.85 (0.82, 0.88), and 0.97 (0.96, 0.98), respectively). Similarity results for associations between serum 25(OH)D₂ and total 25(OH)D with T2DM (ORs (95%CIs): 0.84 (0.81, 0.88) and 0.97 (0.96, 0.99)) were observed, whereas serum 25(OH)D₃ was negatively correlated to T2DM only in the quartile 2 (Q2) and Q3 groups (both p < 0.05). The lipid profile, mainly TC and TG, partly mediated the relationship between 25(OH)D₂ or total 25(OH)D and IFG or T2DM and the proportion explained was from 2.74 to 17.46%. Furthermore, interactive effects of serum 25(OH)D₂, total 25(OH)D, and testosterone on T2DM were observed in females (both p for interactive <0.05), implying that the positive association between serum testosterone and T2DM was vanished when 25(OH)D₂ was higher than 10.04 ng/mL or total 25(OH)D was higher than 40.04 ng/mL. Therefore, ensuring adequate vitamin D levels could reduce the prevalence of IFG and T2DM, especially in females with high levels of testosterone.

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

INTRODUCTION

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

METHODS AND ANALYSIS

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

ETHICS AND DISSEMINATION

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

TRIAL REGISTRATION NUMBER

NCT04082650.

Antioxidants for female subfertility

BACKGROUND

A couple may be considered to have fertility problems if they have been trying to conceive for over a year with no success. This may affect up to a quarter of all couples planning a child. It is estimated that for 40% to 50% of couples, subfertility may result from factors affecting women. Antioxidants are thought to reduce the oxidative stress brought on by these conditions. Currently, limited evidence suggests that antioxidants improve fertility, and trials have explored this area with varied results. This review assesses the evidence for the effectiveness of different antioxidants in female subfertility.

OBJECTIVES

To determine whether supplementary oral antioxidants compared with placebo, no treatment/standard treatment or another antioxidant improve fertility outcomes for subfertile women.

SEARCH METHODS

We searched the following databases (from their inception to September 2019), with no language or date restriction: Cochrane Gynaecology and Fertility Group (CGFG) specialised register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL and AMED. We checked reference lists of relevant studies and searched the trial registers.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared any type, dose or combination of oral antioxidant supplement with placebo, no treatment or treatment with another antioxidant, among women attending a reproductive clinic. We excluded trials comparing antioxidants with fertility drugs alone and trials that only included fertile women attending a fertility clinic because of male partner infertility.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. The primary review outcome was live birth; secondary outcomes included clinical pregnancy rates and adverse events.

MAIN RESULTS

We included 63 trials involving 7760 women. Investigators compared oral antioxidants, including: combinations of antioxidants, N-acetylcysteine, melatonin, L-arginine, myo-inositol, carnitine, selenium, vitamin E, vitamin B complex, vitamin C, vitamin D+calcium, CoQ10, and omega-3-polyunsaturated fatty acids versus placebo, no treatment/standard treatment or another antioxidant. Only 27 of the 63 included trials reported funding sources. Due to the very low-quality of the evidence we are uncertain whether antioxidants improve live birth rate compared with placebo or no treatment/standard treatment (odds ratio (OR) 1.81, 95% confidence interval (CI) 1.36 to 2.43; P < 0.001, I² = 29%; 13 RCTs, 1227 women). This suggests that among subfertile women with an expected live birth rate of 19%, the rate among women using antioxidants would be between 24% and 36%. Low-quality evidence suggests that antioxidants may improve clinical pregnancy rate compared with placebo or no treatment/standard treatment (OR 1.65, 95% CI 1.43 to 1.89; P < 0.001, I² = 63%; 35 RCTs, 5165 women). This suggests that among subfertile women with an expected clinical pregnancy rate of 19%, the rate among women using antioxidants would be between 25% and 30%. Heterogeneity was moderately high. Overall 28 trials reported on various adverse events in the meta-analysis. The evidence suggests that the use of antioxidants makes no difference between the groups in rates of miscarriage (OR 1.13, 95% CI 0.82 to 1.55; P = 0.46, I² = 0%; 24 RCTs, 3229 women; low-quality evidence). There was also no evidence of a difference between the groups in rates of multiple pregnancy (OR 1.00, 95% CI 0.63 to 1.56; P = 0.99, I² = 0%; 9 RCTs, 1886 women; low-quality evidence). There was also no evidence of a difference between the groups in rates of gastrointestinal disturbances (OR 1.55, 95% CI 0.47 to 5.10; P = 0.47, I² = 0%; 3 RCTs, 343 women; low-quality evidence). Low-quality evidence showed that there was also no difference between the groups in rates of ectopic pregnancy (OR 1.40, 95% CI 0.27 to 7.20; P = 0.69, I² = 0%; 4 RCTs, 404 women). In the antioxidant versus antioxidant comparison, low-quality evidence shows no difference in a lower dose of melatonin being associated with an increased live-birth rate compared with higher-dose melatonin (OR 0.94, 95% CI 0.41 to 2.15; P = 0.89, I² = 0%; 2 RCTs, 140 women). This suggests that among subfertile women with an expected live-birth rate of 24%, the rate among women using a lower dose of melatonin compared to a higher dose would be between 12% and 40%. Similarly with clinical pregnancy, there was no evidence of a difference between the groups in rates between a lower and a higher dose of melatonin (OR 0.94, 95% CI 0.41 to 2.15; P = 0.89, I² = 0%; 2 RCTs, 140 women). Three trials reported on miscarriage in the antioxidant versus antioxidant comparison (two used doses of melatonin and one compared N-acetylcysteine versus L-carnitine). There were no miscarriages in either melatonin trial. Multiple pregnancy and gastrointestinal disturbances were not reported, and ectopic pregnancy was reported by only one trial, with no events. The study comparing N-acetylcysteine with L-carnitine did not report live birth rate. Very low-quality evidence shows no evidence of a difference in clinical pregnancy (OR 0.81, 95% CI 0.33 to 2.00; 1 RCT, 164 women; low-quality evidence). Low quality evidence shows no difference in miscarriage (OR 1.54, 95% CI 0.42 to 5.67; 1 RCT, 164 women; low-quality evidence). The study did not report multiple pregnancy, gastrointestinal disturbances or ectopic pregnancy. The overall quality of evidence was limited by serious risk of bias associated with poor reporting of methods, imprecision and inconsistency.

AUTHORS' CONCLUSIONS

In this review, there was low- to very low-quality evidence to show that taking an antioxidant may benefit subfertile women. Overall, there is no evidence of increased risk of miscarriage, multiple births, gastrointestinal effects or ectopic pregnancies, but evidence was of very low quality. At this time, there is limited evidence in support of supplemental oral antioxidants for subfertile women.

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.

Effects of vitamin D supplementation on serum lipid profile in women with polycystic ovary syndrome: A protocol for a systematic review and meta-analysis

BACKGROUND

Polycystic ovary syndrome (PCOS) is the commonest endocrine disorder in reproductive-aged women. In addition to the reproductive consequences, PCOS is also characterized by a metabolic disorder, which may play a part in the etiology of anovulation and has important implications for long-term health as well. Vitamin D deficiency is prevalent in PCOS and there is a close relationship between metabolic dysfunction and vitamin D status in women with PCOS. The purpose of this systematic analysis is to evaluate the effect of vitamin D supplementation on serum lipid profiles in patients with PCOS.

METHODS

We will search five databases for relative studies: Medline, the Cochrane Library, EMBASE, Web of Science, and ClinicalTrials.gov and identified all reports of randomized controlled trials published prior to July 2020. Two authors will independently scan the articles searched, extract the data from articles included, and assess the risk of bias by Cochrane tool of risk of bias. Disagreements will be resolved by discussion among authors. All analysis will be performed based on the Cochrane Handbook for Systematic Reviews of Interventions. Fixed-effects model or random-effects model was used to calculate pooled estimates of weighted mean difference (WMD) with 95% confidence intervals.

RESULTS

This review will be to assess the effect of vitamin D supplementation on serum lipid profiles in patients with PCOS. The results of the study will be published in a scientific journal after peer-review.

CONCLUSIONS

These findings will provide guidance to clinicians and patients on the use of vitamin D for PCOS with dyslipidemia.

ETHICS AND DISSEMINATION

This study is a protocol for a systematic review of vitamin D as a treatment of dyslipidemia in PCOS patients.

SYSTEMATIC REVIEW REGISTRATION

INPLASY202050007.

The Association between Vitamin D and Anti-Müllerian Hormone: A Systematic Review and Meta-Analysis

Accumulating evidence from animal and human studies indicates a role for vitamin D in female reproductive physiology, and numerous clinical studies have suggested its potential benefit for various aspects of human reproduction. Anti-Müllerian hormone (AMH) is an ovarian biomarker that plays an important role in folliculogenesis. It is the most sensitive ovarian reserve marker and is widely used clinically in reproductive medicine. While initial studies have suggested that vitamin D may be associated with ovarian reserve markers, including AMH, evidence has been conflicting. Currently, there is considerable debate in the field whether vitamin D has the capacity to influence ovarian reserve, as indicated by the AMH level. The current systematic review aims to evaluate and summarize the available evidence regarding the relationship between vitamin D and AMH. In total, 18 observational studies and 6 interventional studies were included in this systematic review. Cross-sectional studies have reported largely discrepant findings regarding an association between serum vitamin D and AMH levels, which are likely due to the heterogeneity in study populations, as well as the apparently complex relationship that may exist between vitamin D and AMH. However, meta-analysis of interventional studies performed herein that examined the effects of vitamin D supplementation on serum AMH levels indicates a cause-effect relationship between vitamin D and AMH, the direction of which appears to depend on a woman’s ovulatory status. Serum AMH was significantly decreased following vitamin D supplementation in polycystic ovarian syndrome (PCOS) women (standardized mean difference (SMD) −0.53, 95% CI −0.91 to −0.15, p < 0.007), while it was significantly increased following vitamin D supplementation in ovulatory women without PCOS (SMD 0.49, 95% CI 0.17 to 0.80, p = 0.003). In conclusion, the results of this systematic review demonstrate that the relationship between vitamin D and AMH is a complex one, and large, randomized trials of vitamin D supplementation focusing on different vitamin D status ranges are necessary to gain more insight into the nature of this relationship and the potential benefit of vitamin D to female reproduction in general.

Effect of vitamin D supplementation on polycystic ovary syndrome: A meta-analysis

The aim of the present meta-analysis was to evaluate the effect of vitamin D supplementation on patients with polycystic ovary syndrome (PCOS). A literature search was performed to identify all of the relevant studies comparing the effect of vitamin D supplementation with placebo in PCOS patients, in the PubMed, Embase and Web of Science databases. All statistical analyses were performed on case-control studies using Review Manager 5.3 software, provided by the Cochrane Collaboration. A total of 11 studies involving 483 participants were included in the current meta-analysis. Vitamin D supplementation appeared to lead to an improvement in the levels of total testosterone [weighted mean differences (WMD) = -0.10, 95% CI (-0.18, -0.02)], homeostasis model assessment of insulin resistance [WMD = -0.44, 95% CI (-0.86, -0.03)], homeostasis model assessment of β-cell function [WMD = -16.65, 95% CI (-19.49, -13.80)], total cholesterol [WMD = -11.90, 95% CI (-15.67, -8.13)] and low-density lipoprotein-cholesterol [WMD = -4.54; 95% CI (-7.29, -1.80)]. The results failed to show a positive effect of vitamin D supplementation on the body mass index, dehydroepiandrosterone sulfate, triglyceride levels or high-density lipoprotein-cholesterol. In conclusion, the data from the available randomized controlled trials (RCTs) suggested vitamin D supplementation reduced insulin resistance and hyperandrogenism, as well improving the lipid metabolism of patients with PCOS to an extent. Further high-quality RCTs from a variety of regions in the world are required to determine the effectiveness of vitamin D supplementation in PCOS patients, and to determine a suitable dose and unit of vitamin D.

Efficacy of Vitamin D Combined with Metformin and Clomiphene in the Treatment of Patients with Polycystic Ovary Syndrome Combined with Infertility

BACKGROUND

We aimed to explore the clinical efficacy of vitamin D combined with metformin and clomiphene in the treatment of patients with polycystic ovary syndrome combined with infertility.

METHODS

Overall, 396 cases of polycystic ovarian syndrome combined with infertility in Yantai Yuhuangding Hospital, Yantai, China were prospectively analyzed. Among them, 204 cases treated with vitamin D combined with metformin and clomiphene were set as the study group; 192 cases treated with only metformin and clomiphene were set as the control group. The ovarian volume and thickness of uterine wall before and after treatment were recorded. Levels of fasting insulin (FINS), luteinizing hormone (LH), testosterone (T), follicle-stimulating hormone (FSH), and estradiol (E2) before and after treatment were recorded.

RESULTS

There was no difference in body weight, BMI, ovarian volume, thickness of ovarian wall, FINS, LH, T, FSH and E2 between the study group and the control group; there was no significant difference in FSH, E2 and the thickness of uterine wall between the two groups. After treatment, the BMI, FINS, LH, and T in the study group were significantly lower than those in the control group (P<0.05); the incidence rates of oligomenorrhea, facial acne and hairy symptoms in the study group were significantly lower than those in the control group (P<0.05); after treatment, the ovulation rate and pregnancy rate in 36 cycles in the observation group were significantly higher than those of the control group (P<0.05).

CONCLUSION

Our challenge could significantly improve clinical symptoms and endocrine conditions, and greatly enhance the ovulation rate and pregnancy rate.

Diabetic Hemodialysis: Vitamin D Supplementation and its Related Signaling Pathways Involved in Insulin and Lipid Metabolism

BACKGROUND

This study was conducted to determine the effects of vitamin D supplementation on some of the gene expressions related to insulin and lipid metabolism in diabetic hemodialysis (HD) patients.

METHODS

A double-blind, randomized, placebo-controlled clinical trial was carried out in 55 patients with diabetic HD. The current project used two groups in which each subject received vitamin D supplements (50,000 IU, n=28) or placebo (50,000 IU, n=27) every 2 weeks for 12 weeks. Gene expression analyses (RT-PCR) were included to obtain the rate of gene expression of the related insulin and lipid metabolism genes in peripheral blood mononuclear cells (PBMCs) of patients with diabetic HD.

RESULTS

Our data revealed that consumption of vitamin D supplementation enables to overexpress the peroxisome proliferation-activated receptor gamma (PPAR-γ) (P=0.001), AKT (P=0.04), PI3K (P=0.02), insulin receptor substrate-1 (IRS1) (P0.008) and glucose transporter type 4 (GLUT-4) (P=0.01) and downregulate the expression of protein kinase C (PKC) (P=0.001) in patients with diabetic HD than control group following the 12-week intervention. In addition, vitamin D supplementation downregulated low-density lipoprotein receptor (LDLR) (P=0.03) expression in the subjects with diabetic HD than the control group. Vitamin D supplementation did not show any effects on the expression of pyruvate dehydrogenase kinase 1 (PDK1) (P=0.37), IRS2 (P=0.90) and lipoprotein (a) [Lp(a)] (P=0.05).

CONCLUSION

Our findings confirmed that diabetic HD subjects who received the vitamin D supplementation (for 12 weeks), showed a significant overexpression in the PPAR-γ, AKT, PI3K, IRS1 and GLUT4 genes, and also showed a significant downregulation in the PKC and LDLR genes. Moreover, no effects on PDK1, IRS2 and Lp(a) expression were observed.