Influence of vitamin D levels on in vitro fertilization outcomes in donor-recipient cycles

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

INTRODUCTION

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Supplementation with vitamin D improves the embryo quality in in vitro fertilization (IVF) programs, independently of the patients' basal vitamin D status

PURPOSE

The study aims to demonstrate the effects of Vitamin D (VD) supplementation, prior to oocyte pick-up within IVF protocols, in women with diverse VD status at the enrollment.

METHODS

A total of 204 women eligible for intra-cytoplasmatic sperm injection (ICSI) cycles were included in the study and two homogeneous groups were selected from the database. Both group of patients with normal VD baseline level (> 40 ng/ml) and patients with low VD baseline level (< 20 ng/ml) were divided into control group and treatment group. The control group followed the standard procedure. The treatment group was supplemented with vitamin D3 as cholecalciferol in combination with Myo-Inositol, folic acid, and melatonin 3 months before standard procedure, once a day in the evening.

RESULTS

VD levels significantly increased in the study group of low baseline VD, both in serum and in the follicular fluid compared to controls. The treatment induced a significant improvement of the embryo quality in both group of patients considered.

CONCLUSION

Supplementation of VD in patients undergoing ICSI procedures significantly improved the number of top-quality embryos compared with the control group, either starting from VD normal baseline values or starting from low values.

TRIAL REGISTRATION NUMBER

07/2018.

Association Between Vitamin D Level and Clinical Outcomes of Assisted Reproductive Treatment: A Systematic Review and Dose-Response Meta-Analysis

The investigation about association between vitamin D level and clinical outcomes of assisted reproductive treatment showed various outcomes. This study aimed to review the correlation between vitamin D and outcomes of assisted reproductive treatment. The search was registered on the PROSPERO database (CRD42023458040). PubMed, Embase, Medline, ClinicalTrials.gov, and Cochrane databases were searched up to July 2023. Twenty-three observational studies were selected for meta-analysis. Comparing groups with deficient and 'insufficient + sufficient' vitamin D level, meta-analysis showed positive correlation between clinical pregnancy rate and vitamin D (OR 0.81, 95%CI: 0.70, 0.95, P = 0.0001). Comparing groups with 'deficient + insufficient' and sufficient vitamin D level, meta-analysis showed positive correlation between vitamin D and clinical pregnancy rate (OR 0.71, 95%CI: 0.55, 0.91, P = 0.006), vitamin D and live birth rate (OR 0.69, 95%CI: 0.54, 0.89, P = 0.003). Subgroup analysis did not show the source of high heterogeneity. No correlation was found in biochemical pregnancy rate, ongoing pregnancy rate, miscarriage rate and implantation rate. In dose-response meta-analysis, a nonlinear association was found between vitamin D levels and outcomes when levels are below approximately 24 ng/L. The study shows that vitamin D level is associated with clinical pregnancy rate and live birth rate. Low vitamin D level does not influence biochemical pregnancy rate, ongoing pregnancy rate, miscarriage rate and implantation rate. Furthermore, 24 ng/L may be a possible threshold of vitamin D concentration in assisted reproduction therapy.

Targeted metabolomics profiling in pregnancy associated with vitamin D deficiency

BACKGROUND

Vitamin D deficiency is common in pregnancy, however, its effects has not been fully elucidated. Here, we conducted targeted metabolomics profiling to study the relationship.

METHODS

This study enrolled 111 pregnant women, including sufficient group (n = 9), inadequate group (n = 49) and deficient group (n = 53). Ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS)-based targeted metabonomics were used to characterize metabolite profiles associated with vitamin D deficiency in pregnancy.

RESULTS

Many metabolites decreased in the inadequate and deficient group, including lipids, amino acids and others. The lipid species included fatty acyls (FA 14:3, FA 26:0; O), glycerolipids (MG 18:2), glycerophospholipids (LPG 20:5, PE-Cer 40:1; O2, PG 29:0), sterol lipids (CE 20:5, ST 28:0; O4, ST 28:1; O4). Decreased amino acids included aromatic amino acids (tryptophan, phenylalanine, tyrosine) and branched-chain amino acids (valine, isoleucine, leucine), proline, methionine, arginine, lysine, alanine, L-kynurenine,5-hydroxy-L-tryptophan, allysine.

CONCLUSIONS

This targeted metabolomics profiling indicated that vitamin D supplementation can significantly affect lipids and amino acids metabolism in pregnancy.

A review of the optimization of thyroid function, thrombophilia, immunity and uterine milieu treatment strategy for recurrent implantation failure and recurrent pregnancy loss

Background

Aside from embryonic factors, various factors can intricately interfere with embryo implantation and maintenance of pregnancy, causing recurrent implantation failure (RIF) or recurrent pregnancy loss (RPL). This review focuses the optimization of thyroid function, thrombophilia, immunity, and uterine milieu (OPTIMUM) treatment strategy on RIF and RPL.

Methods

Three studies employing the OPTIMUM treatment strategy for patients with RIF and/or RPL were reviewed.

Results

The OPTIMUM improved pregnancy rates in women with RIF aged <40 years. Among advanced age women, however, no significant differences in pregnancy rates were observed between the control, OPTIMUM, and preimplantation genetic testing for aneuploidy (PGT-A) groups, although pregnancy rates were highest after OPTIMUM + PGT-A. The OPTIMUM reduced miscarriage rates in women with RPL aged <40 years. Among advanced age women, PGT-A, but not the OPTIMUM, contributed to miscarriage prevention. Factors predicting pregnancy success in women with RIF who received the OPTIMUM included thrombophilia and young age. Risk factors for an unsuccessful live birth among women with RPL who received the OPTIMUM included advanced age, infertility, diminished ovarian reserve, and non-ART treatment.

Conclusions

The OPTIMUM can improve pregnancy outcomes in women with RIF/RPL, except for advanced age women with embryonic factor-induced reproductive failure.

Biological Pathways Associated with Vitamins in Autism Spectrum Disorder

Autism spectrum disorder (ASD) is characterized by early-appearing social communication deficits, with genetic and environmental factors potentially playing a role in its etiology, which remains largely unknown. During pregnancy, certain deficiencies in critical nutrients are mainly associated with central nervous system impairment. The vitamin B9 (folate) is primarily related to one-carbon and methionine metabolism, participating in methyl donor generation. In addition, supplementation with folic acid (FA) is recommended by the World Health Organization (WHO) in the first three gestational months to prevent neural tube defects. Vitamin B12 is related to folate regeneration, converting it into an active form. Deficiencies in this vitamin have a negative impact on cognitive function and brain development since it is involved in myelin synthesis. Vitamin D is intimately associated with Ca2+ levels, acting in bone development and calcium-dependent signaling. This vitamin is associated with ASD at several levels since it has a relation with ASD genes and oxidative stress environment. This review carries the recent literature about the role of folate, vitamin B12, and vitamin D in ASD. In addition, we discuss the possible impact of nutrient deficiency or hypersupplementation during fetal development. On the other hand, we explore the biases of vitamin supplementation studies such as the loss of participants in retrospective studies, as well as multiple variants that are not considered in the conclusion, like dietary intake or auto-medication during pregnancy. In this regard, we aim to contribute to the discussion about the role of vitamins in ASD currency, but also in pregnancy and fetal development as well. Furthermore, stress during pregnancy can be an ASD predisposition, with cortisol as a regulator. In this view, we propose that cortisol is the bridge of susceptibility between vitamin disorders and ASD prevalence.

Prevalence of 25-Hydroxyvitamin D (Vitamin D) Deficiency in a Group of Infertile Women from Baghdad City

Background

Infertility is a common issue affecting a large number of Iraqi women of reproductive age. The relationship between vitamin D deficiency and infertility has previously drawn the attention of gynecologists, and an increasing number of vitamin D testing has been requested.

Methods

120 women were enrolled in this study between April 2019 and April 2020. Patients were divided into two groups comprising sixty women complaining of infertility, with the other 60 women being fertile and enrolled as controls. All patients were assessed for vitamin D level.

Results

In the fertile study group, patients with deficient, insufficient, and sufficient level of vitamin were 28%, 23%, and 48%, respectively (these numbers were rounded to the nearest whole digit, as the numbers for the infertile group were given with that level of precision), whereas the infertile study group showed a statistically significant (p value = 0.002) distribution of vitamin levels with 50%, 35%, and 15% of women being deficient, insufficient, and sufficient, respectively.

Conclusions

Vitamin D is significantly deficient in infertile patients which suggests a possible, positive impact if vitamin D is considered in the management of female infertility. Further study with more participants is highly recommended.

Severity of Menstrual Pain Is Associated with Nutritional Intake and Lifestyle Habits

Recently, the employment rate of women in Japan has steadily increased. Approximately 80% of women experience menstrual pain and premenstrual syndrome (PMS). These symptoms decrease a woman's quality of life and her work productivity, leading to an economic loss. This cross-sectional study of 321 healthy Japanese women aged 20-39 years aimed to clarify the lifestyle-related factors or nutrient intake that might cause menstrual pain. The participants underwent body composition measurements and completed meal survey sheets and lifestyle questionnaires, including menstrual status, exercise, sleep and breakfast consumption. Based on the questionnaire results, participants were divided into two groups according to the severity of menstrual pain, namely, heavy and light. Chi-square and Wilcoxon signed-rank sum tests were used to compare the severity of menstrual pain in the two groups. In the heavy group, the intake of animal proteins, including fish, vitamin D and vitamin B12, was significantly lower (p < 0.05), as was the frequency of breakfast consumption and bathing (p < 0.05). The rate of PMS symptoms was significantly higher in the heavy group (p < 0.05). This study suggests that a lack of animal protein, the accompanying vitamins and fatty acids, and the frequency of breakfast or bathing are associated with the severity of menstrual pain.

Vitamin D and in vitro fertilization: a systematic review

PURPOSE

Vitamin D (VD) action on calcium is well known, but its other properties, particularly in the human reproductive system, are not completely understood. This review aims at assessing the relationship between serum VD levels and IVF results.

METHODS

A systematic review was carried out using MEDLINE, EMBASE, LILACS, Google scholar, the CAPES journal portal, and the Cochrane Library, as well as the descriptors "vitamin D" and "fertilization in vitro." The review was conducted by two authors following the PRISMA recommendations between September 2021 and February 2022.

RESULTS

Eighteen articles were selected. Five of them showed a positive correlation between serum VD levels and IVF results, 12 lacked any association, and 1 exhibited a negative correlation. The 3 studies that assessed VD in the follicular fluid found a positive correlation between the serum and follicular levels. Non-Hispanic White patients seemed to suffer the consequence of vitamin D deficiency more than Asian patients. In one study alone in the VD-deficient group, there was a larger number of natural killer (NK) cells, B cells, a greater proportion of helper T cells/cytotoxic T cells (Th/Tc), and an association with a smaller number of mature oocytes.

CONCLUSION

The association between serum VD levels and the post-IVF pregnancy rate is uncertain. However, VD levels might be more relevant in the White than in the Asian ethnicity and in the number of aspiration follicles, and they could act in the immune system having an impact both on embryo implantation and on pregnancy.

Dietary supplementation for female infertility: Recent advances in the nutritional therapy for premature ovarian insufficiency

Premature ovarian insufficiency (POI) ranks top in the reproductive disorders that may impair multiple functioning systems, reduce the quality of life and ultimately deprive patients of their fertility among women. Symptoms can be partially alleviated by present hormone replacement therapy that cannot improve conception or decrease occurrence rates of systemic complication. Nutritional dietary supplements are attracting more and more attention because of their safety, bioavailability, and efficacy for well-being. Nutrients in the daily food are composed of carbohydrates, fat and lipoprotein, protein and polypeptide, vitamins, and vegetable or fruits containing phytoestrogens. These are functional nutrients due to the proliferative, anti-inflammatory, anti-oxidant, and mitochondria-protective potential during the course of menopause. Apart from dietary nutrients, microbe-related nutritional substances, including probiotics, prebiotics and the combination-synbiotics, display high potential as well in supporting estrous cycle, ovarian viability and modulating other vital reproductive functions. The present review will discuss dietary and microbial nutrients and their roles and applications in the living body based upon animal or human research, evaluate possible effect mechanisms from molecular, cellular and tissue levels, and provide insights into nutritional therapy for prolonging reproductive lifespan in female patients.

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.

Follicular fluid 25-hydroxyvitamin D levels determine fertility outcome in patients with polycystic ovary syndrome

OBJECTIVE

To determine the possible relationship between follicular fluid 25-hydroxyvitamin D [25(OH)D] levels and fertility outcome of women who underwent IVF/ICSI with the diagnosis of lean polycystic ovary syndrome.

MATERIALS AND METHODS

Thirty patients who were diagnosed with PCOS according to the Rotterdam criteria and decided on IVF/ICSI were included in the study. Thirty patients who were scheduled for IVF/ICSI for reasons other than PCOS and matched in terms of age and BMI were taken as the control group (non-PCOS). According to BMI values, patients in both PCOS and non-PCOS groups were lean. Women in both groups were aged 21-35 years with a normal BMI (18.5-24.9 kg/m2) and first IVF/ICSI attempt. Both groups of patients were followed up using the antagonist protocol. Vit D levels were measured in serum and follicular fluid (FF) samples taken on the day of oocyte collection. The correlation between FF vit D levels, the number of total oocytes, MII oocytes and 2 PN zygotes, HOMA-IR, hormonal and demographic parameters, clinical pregnancy rate (CPR), live birth rate (LBR), and miscarriage rate were evaluated.

RESULTS

At the time of oocyte retrieval women with PCOS had similar serum Vitamin D compared to non-PCOS women (21.8 (12.6-24.8) ng/ml vs 22.3 (11.5-25.1) ng/ml, p < 0.54). In FF, assessed on the day of oocyte retrieval, the concentration of Vitamin D was similar in women with PCOS when compared to non-PCOS women (11.2 (9.2-14.4) ng/ml vs 13.3 (11.1-17.4) ng/ml, p < 0.06). For both groups, Vitamin D levels were lower in FF compared to serum vit D. A positive correlation was found between serum and FF Vitamin D concentrations in the full cohort. A positive and significant correlation was found between FF-vit D levels and the number of total oocyte (r = 0.344, p < 0.04) and MII oocyte (r = 0.404, p < 0.02) in the PCOS group. The number of total oocyte, MII oocyte and 2 PN zygotes of the PCOS group were significantly higher than the non-PCOS group. Positive pregnancy test rate, clinical pregnancy and live birth rates were similar in both groups. The miscarriage rates in the non-PCOS group were significantly higher than in the PCOS group. A positive and significant correlation was also found between FF vit D levels and positive pregnancy test (r = 0.566, p < 0.03) and CPR (r = 0.605, p < 0.02) in PCOS group. There was no correlation between FF-vit D levels and live birth and miscarriage rates in neither the PCOS nor the non-PCOS group.

CONCLUSIONS

Both serum and FF 25-hydroxyvitamin D level of women with PCOS at the time of oocyte retrieval are similar to non-PCOS controls. While FF 25-hydroxyvitamin D levels correlate with total and MII oocyte counts, positive pregnancy test and CPR, it does not correlate with miscarriage and live birth rates.

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.

Vitamin D: Before, during and after Pregnancy: Effect on Neonates and Children

A worldwide high prevalence of vitamin D (VD) deficiency has become of growing concern because of potential adverse effects on human health, including pregnant women and their offsprings. Beyond its classical function as a regulator of calcium and phosphate metabolism, together with its fundamental role in bone health in every stage of life, its deficiency has been associated to multiple adverse health effects. The classic effects of VD deficiency in pregnancy and neonates have been late hypocalcemia and nutritional rickets. Nevertheless, recent studies have linked VD to fertility and 25(OH)D with several clinical conditions in pregnancy: preeclampsia, gestational diabetes, higher incidence of cesarean section and preterm birth, while in infants, the clinical conditions are low birth weight, lower bone mass and possible relationship with the development of such diseases as bronchiolitis, asthma, type 1 diabetes, multiple sclerosis and autism included as VD non-classical actions. The supplementation with Vitamin D and achievement of optimal levels reduce maternal-fetal and newborn complications. Supplementation in children with VD deficiency reduces the risk of respiratory infections and possibly autoimmune diseases and autism. This review emphasizes the roles of Vitamin D deficiency and the consequences of intervention from preconception to infancy.

Induction of Endometrial HOXA 10 Gene Expression by Vitamin D and its Possible Influence on Reproductive Outcome of PCOS Patients Undergoing Ovulation Induction Procedure

BACKGROUND AND OBJECTIVES

Polycystic ovarian syndrome (PCOS) is one of the most common endocrinopathies in women frequently presenting with anovulatory infertility. Low successful pregnancy and live birth rates even after successful ovulation induction (OI) and in vitro fertilization (IVF) in these patients indicate that endometrial dysfunction may be another important factor contributing to infertility. Vitamin D acting through nuclear receptors induces the expression of various genes required for cell growth and differentiation and plays a crucial role in reproduction. Homeobox 10 (HOXA10) may be one of the potential targets for vitamin D action. HOXA10 gene product promotes the differentiation of endometrial cells, making the endometrium receptive for implantation. The present study was undertaken to determine the effect of circulating vitamin D levels on HOXA10 gene expression in endometrial tissues and its possible influence on the reproductive outcome of PCOS patients undergoing OI procedure.

MATERIALS AND METHODS

A prospective cohort study was conducted on 110 infertile PCOS patients. The patients were divided into two groups: Group 1: Vitamin D ³20 ng/ml, Group 2: Vitamin D <20 ng/ml. Endometrial samples were obtained from 22 patients using pipelle biopsy, used to determine HOXA10 mRNA (messenger ribonucleic acid) expression by quantitative RT-PCR (reverse transcription-polymerase chain reaction) and protein expression by Western blotting. OI was performed using Clomiphene citrate or Letrozole from the 3^rd day of the cycle, and patients were followed up for a maximum of five cycles. Attainment of successful pregnancy was considered a positive outcome.

RESULTS

Both the groups were similar in mean age and other endocrine parameters. Serum vitamin D levels were significantly low (P < 0.001), and BMI (body mass index) was significantly high (P = 0.032) in group 2 compared to group 1. Endometrial HOXA10 mRNA (by quantitative rtPCR) and protein expression (by western blotting) were significantly low in group 2 compared to group 1. The clinical pregnancy rate was low in group 2 (28.6%) compared to group 1 (42.3%), but this difference was not significant (P = 0.22). On regression analysis adjusted for age and BMI, vitamin D was an independent predictor of successful pregnancy after OI (P = 0.09).

CONCLUSION

Circulating vitamin D levels influence the endometrial HOXA10 gene expression, and this may be reflected on the reproductive outcome of infertile PCOS patients undergoing OI.

Calcifediol (25OHD) Deficiency and Its Treatment in Women's Health and Fertility

Currently, there is abundant scientific evidence showing that the vitamin D endocrine system (VDES) is a highly complex endocrine system with multiple actions in different regions of the body. The unequivocal presence of vitamin D receptors in different tissues related to fertility, and to specific aspects of women’s health such as pregnancy, undoubtedly implies functions of this steroid hormone in both male and female fertility and establishes relationships with different outcomes of human gestation. In order to review the role of the VDES in human fertility, we evaluated the relationships established between 25-hydroxyvitamin D (calcifediol) deficiency and in vitro fertilization, as well as aspects related to ovarian reserve and fertility, and commonly diagnosed endocrinopathies such as polycystic ovary disease. Likewise, we briefly reviewed the relationships between calcifediol deficiency and uterine fibroids, as well as the role that treatment may have in improving human fertility. Finally, the best scientific evidence available on the consequences of calcifediol deficiency during pregnancy is reviewed in relation to those aspects that have accumulated the most scientific literature to date, such as the relationship with the weight of the newborn at the time of delivery, the appearance of preeclampsia, and the risk of developing gestational diabetes and its final consequences for the pregnancy. To date, there is no definitive consensus on the necessary dose for treatment of calcifediol deficiency in the therapeutic management of infertility or during pregnancy. Large prospective clinical intervention studies are needed to clarify the benefits associated with this supplementation and the optimal dose to use in each situation. Although most intervention studies to date have been conducted with cholecalciferol, due to its much longer history of use in daily care, the use of calcifediol to alleviate 25-hydroxyvitamin D deficiency seems safe, even during pregnancy. The unequivocal presence of vitamin D receptors in very different tissues related to human fertility, both male and female, as well as in structures typical of pregnancy, allows us to investigate the crucial role that this steroid hormone has in specific aspects of women’s health, such as pregnancy and the ability to conceive. Well-designed clinical studies are needed to elucidate the necessary dose and the best form of treatment to resolve the very common calcifediol deficiency in women of reproductive age.

Effect of 1,25(OH)2-vitamin D3 on decidualization of human endometrial stromal cells

Decidualization is the differentiation of endometrial stromal cells (eSC) to rounded, epithelioid-like cells during menstrual cycle and pregnancy. The impairment of this process leads to infertility and a variety of pregnancy disorders, including recurrent miscarriages and uteroplacental disorders. The aim of this study was to evaluate the effect of 1,25(OH)2-vitamin D3 (VD) on transformation of primary eSC into decidual cells. After isolation of eSC from biopsy samples of healthy fertile women and their characterization, the cells were cultured and propagated, and confluent cultures were decidualized for 12 days with progesterone (P4) and estradiol (E2) in presence or absence of VD. Prolactin (PRL) concentration was measured every 48 h in culture medium of eSCs, and ultrastructural changes were evaluated at the end of treatment. The results showed that PRL concentration in culture medium of eSCs was significantly increased in VD-treated decidual cells compared to control groups in a time-dependent manner. Ultrastructural analysis demonstrated that VD enhances many of the ultrastructural changes of decidualized cells including expansion of rough endoplasmic reticulum (rER), increased lipid droplets and high number of euchromatin round nuclei. These results suggest that VD may play an important role during early pregnancy by promoting cellular transformation associated with decidualization.

Dietary supplementation with canthaxanthin and 25-hydroxycholecalciferol on the incubation performance and fertility of European quail breeders

This study assessed the effects of combined supplementation with canthaxanthin (Cx) and 25-hydroxycholecalciferol (25-OH-D₃) on incubation performance, fertility, and chick quality in European quail breeders. A total of 240 birds were distributed in a completely randomized design with 5 diets and 8 replicates. The animals were fed a basal diet containing 50 µg of vitamin D₃ or the basal diet supplemented with 3 ppm Cx and 34.5 µg 25-OH-D₃, 6 ppm Cx, and 69 µg 25-OH-D₃, 9 ppm Cx and 103.5 µg 25-OH-D₃, or 12 ppm Cx and 138 µg 25-OH-D₃. Incubation performance was analyzed in 2 periods (32 and 38 wk). Breeders aged 32 wk produced eggs with higher hatchability (P = 0.024), hatchability of fertile eggs (P = 0.026) and lower initial plus mid embryonic mortality (P = 0.021), whereas 38-week-old breeders generated chicks with a higher length at hatching (P < 0.001) and lower final plus pipped embryonic mortality (P = 0.021). In both age groups, Cx + 25-OH-D₃ levels had a quadratic effect on egg fertility (P < 0.001), hatchability of total (P < 0.001), and fertile eggs (P < 0.001). The fertility and the number of sperm cells in the perivitelline membrane was analyzed in two periods (26 and 40 wk). A quadratic effect of diet and days after mating on both parameters (P < 0.05) was observed. Eggs from supplementing breeders showed a high fertility (P < 0.001) and sperm cell counts (P < 0.001) for up to 7 and 3 d after mating, respectively, then the control group. Moreover, the supplementation of quail breeder diets with 6 ppm Cx + 69 µg 25-OH-D₃ enhances sperm cell longevity in sperm storage tubules, hatchability of total and fertile eggs, fertility, and chick quality, especially in older quail's breeders and reduces embryonic mortality.

100 YEARS OF VITAMIN D: Effect of serum vitamin D level before ovarian stimulation on the cumulative live birth rate of women undergoing in vitro fertilization: a retrospective analysis

OBJECTIVE

Vitamin D receptors are present in the female reproductive tract. Studies on the association between serum vitamin D level and pregnancy rate of in vitro fertilization (IVF) showed inconsistent results and focused on a single fresh or frozen embryo transfer cycle. The objective of our study was to evaluate if serum vitamin D level before ovarian stimulation was associated with the cumulative live birth rate (CLBR) of the first IVF cycle.

DESIGN

Retrospective cohort study.

METHODS

Women who underwent the first IVF cycle from 2012 to 2016 at a university-affiliated reproductive medicine center were included. Archived serum samples taken before ovarian stimulation were analyzed for 25(OH)D levels using liquid chromatography-mass spectrometry.

RESULTS

In total, 1113 had pregnancy outcome from the completed IVF cycle. The median age (25th-75th percentile) of the women was 36 (34-38) years and serum 25(OH)D level was 53.4 (41.9-66.6) nmol/L. The prevalence of vitamin D deficiency (less than 50 nmol/L) was 42.2%. The CLBR in the vitamin D-deficient group was significantly lower compared to the non-deficient group (43.9%, 208/474 vs 50.9%, 325/639, P = 0.021, unadjusted), and after controlling for women's age, BMI, antral follicle count, type and duration of infertility. There were no differences in the clinical/ongoing pregnancy rate, live birth rate and miscarriage rate in the fresh cycle between the vitamin D deficient and non-deficient groups.

CONCLUSIONS

Vitamin D deficiency was prevalent in infertile women in subtropical Hong Kong. The CLBR of the first IVF cycle in the vitamin D-deficient group was significantly lower compared to the non-deficient group.

OUP accepted manuscript

STUDY QUESTION

Is oral Vitamin D supplementation able to modify the intrauterine milieu in terms of cytokine/chemokine pattern?

SUMMARY ANSWER

No significant differences were detected in cytokine and chemokine levels in endometrial secretions between patients undergoing ART with or without Vitamin D supplementation.

WHAT IS KNOWN ALREADY

Cytokines and chemokines secreted into the intrauterine environment are fundamental for the molecular crosstalk between the endometrium and the preimplantation embryo. Whether Vitamin D can regulate these mediators in the endometrial environment is still unclear.

STUDY DESIGN, SIZE, DURATION

This study was an analysis of a secondary outcome from the Supplementation of Vitamin D and Reproductive Outcomes—SUNDRO—clinical trial, a multicenter randomized double-blinded trial designed to explore the effects of Vitamin D replacement in women with Vitamin D levels below 30 ng/ml undergoing autologous ART cycles. Uterine fluid samples were collected from both patients supplemented with Vitamin D (n = 17) and from the placebo group (n = 32).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Based on cutoff points for Vitamin D insufficiency (20–29.9 ng/ml) or deficiency (<20 ng/ml), 67% of patients in the study were insufficient, and 33% deficient, in Vitamin D, although they were considered together for the analysis. Women received a single dose of 600 000 IU 25-hydroxyvitamin D or placebo from 2 to 12 weeks before oocyte retrieval. Inclusion criteria were female age 18–39 years, with a BMI between 18 and 25 kg/m². Serum 25-hydroxyvitamin D was assessed at the time of hCG administration. Uterine fluid samples were collected during the secretory phase of the menstrual cycle preceding oocyte retrieval. The quantitative determination of 27 cytokines in endometrial secretion samples was performed by using a multiplex immunoassay.

MAIN RESULTS AND THE ROLE OF CHANCE

Uterine fluid samples were collected after a median (range) of 21 (12–41) days after the oral Vitamin D supplementation. Both the supplemented and placebo groups had Vitamin D serum levels below 30 ng/ml at baseline/time of randomization ((median 23.4 ng/ml (interquartile range 19.5–28.4) and 23.4 ng/ml (17.8–25.9), respectively). At the time of hCG administration, serum Vitamin D in supplemented subjects was significantly raised compared to the placebo group ((median 52.9 ng/ml (interquartile range 40.7–64.1) and 24.6 ng/ml (19.3–29.2), respectively, P < 0.001). Our data revealed no significant differences in uterine fluid cytokine/chemokine composition of Vitamin D-supplemented women compared with the placebo group. This finding remained when the concentrations of all mediators studied were normalized to total protein. In a further analysis, no significant differences were found in the content of cytokines/chemokines in uterine fluid from women who conceived (n = 19) compared with the nonpregnant group (n = 30).

LIMITATIONS, REASONS FOR CAUTION

Using a randomized study design (a single dose of 600 000 IU 25-hydroxyvitamin D versus placebo), we found no significant differences between groups. However, we cannot exclude that any benefit of Vitamin D supplementation may be specific for some subgroups of patients, such as those with an imbalance of T-helper 1 and T-helper 2 cell populations. The uterine secretions were collected during the menstrual cycle that preceded oocyte retrieval; therefore, it is possible the uterine fluid collection and analysis in the same cycle of the embryo transfer might have resulted in different conclusions. Moreover, the small sample size could limit the power of the study.

WIDER IMPLICATIONS OF THE FINDINGS

Our analysis of the uterine secretome profiling failed to show any significant difference in endometrial cytokine/chemokine patterns between women with oral Vitamin D supplementation and the placebo group. Vitamin D may act on the uterine environment through a different mechanism.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by the Italian Ministry of Health following peer review in the competitive ‘Bando di Ricerca Finalizzata e Giovani Ricercatori 2013’ with reference code RF-2013-02358757. The authors declare that they have no conflict of interest.

TRIAL REGISTRATION NUMBER

EudraCT registration number: 2015-004233-27.

Effect of Vitamin D Supplementation on In Vitro Fertilization Outcomes: A Trial Sequential Meta-Analysis of 5 Randomized Controlled Trials

Despite numerous studies indicating an imperative role of vitamin D for reproduction, the importance of vitamin D supplementation on in vitro fertilization (IVF) outcomes remains controversial. We therefore performed this meta-analysis to investigate the IVF outcomes of vitamin D supplementation in infertile women with vitamin D deficiency. We systematically searched PubMed, Embase and the Cochrane library for identifying all relevant studies published before August 2021. Pregnancy rate was defined as the primary outcome while good quality embryo, fertilization rate, ongoing pregnancy, and miscarriage were secondary outcomes. We used Review Manager 5.3 (RevMan) to conduct meta-analysis and examined the robustness of the primary outcome by trial sequential analysis. Five studies were included in the final analysis and it suggested that vitamin D supplementation was associated with improved chemical pregnancy rate (risk ratio [RR] = 1.53, 95% confidence interval [CI] = 1.06 to 2.20, p = 0.02) but not benefited in improving clinical pregnancy rate (RR = 1.34, 95% CI = 0.81 to 2.24, p = 0.25) and all secondary outcomes. Trial sequential analysis suggested further studies are needed to confirm this conclusion. We concluded that vitamin D supplementation should be prescribed to improve chemical pregnancy in infertile women with vitamin D deficiency and more studies are required to further confirm this finding.

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

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

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

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

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

The Effects of Serum and Follicular Fluid Vitamin D Levels on Assisted Reproductive Techniques: A Prospective Cohort Study

BACKGROUND

Based on studies on animal models, vitamin D plays an essential role in reproduction by controlling Ca and Mg levels. Despite these findings, the effects of vitamin D deficiency and supplementation on the outcome of assisted reproductive techniques (ART) remain controversial. Therefore, the aim of the present study was to assess the relationship between serum and follicular fluid 25-OH vitamin D levels on reproductive outcomes of infertile women.

MATERIALS AND METHODS

This prospective cohort study included 150 infertile women who underwent in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). The participants were allocated to one of the three groups according to their serum and follicular fluid 25-OH vitamin D concentrations (less than 10 ng/ml, between 10 and 30 ng/ ml and more than 30 ng/ml), and fertilization, cleavage and biochemical and clinical pregnancy rates were compared among the groups. Data was analyzed by SPSS software and using Chi-square and Spearman correlation coefficient.

RESULTS

Serum and follicular fluid vitamin D levels significantly correlated with biochemical (P=0.008), (P=0.003) and clinical pregnancy (P=0.017), (P=0.001) rates respectively . However, the quality of embryos (P=0.125), (P=0.106) and fertilization rate (P=0.082), (P=0.059) were not associated with the level of serum and follicular fluid vitamin D.

CONCLUSION

This study found that women with higher levels of vitamin D in their serum and follicular fluid are significantly more likely to achieve pregnancy but without affecting the quality of embryo and fertility rate.

Low vitamin D levels in follicular fluid, but not in serum, are associated with adverse outcomes in assisted reproduction

PURPOSE

To assess the relationship between serum/follicular fluid (FF) vitamin D (VD) status and assisted reproductive technology (ART) treatment outcomes among infertile patients.

METHODS

A prospective cohort study, including 132 infertile patients scheduled for their first ART treatment cycle, was carried out in a Reproductive Medical Center. Serum and FF samples were collected to assess 25-hydroxy VD [25(OH)D] levels. Low VD level was defined as 25(OH)D concentration of less than 30 ng/mL.

RESULTS

Most infertile patients had low VD levels in serum (88%) and FF (90%). We observed a moderately positive correlation between VD levels in serum and FF (r = 0.34, p < 0.0001). Compared to the group of patients with low VD levels in the FF, those with sufficient VD levels had a significantly higher number of retrieved oocytes (p = 0.03), normal fertilization (p = 0.01), and high-quality embryos (p = 0.001). Moreover, patients with sufficient VD levels in the FF also had significantly higher implantation rates than those with low VD levels (76.92% vs. 46.58%, respectively, p = 0.01) and clinical pregnancy rates (92.31% vs. 61.54%, respectively, p = 0.04).

CONCLUSION

These data collectively revealed that low VD levels in serum and FF were common among infertile patients. VD levels in FF, but not in serum, were associated with embryo quality, normal fertilization, implantation rates, and clinical pregnancy rates. Further studies are mandatory to determine the molecular mechanism and VD's potential therapeutic benefits in infertile patients.

Evaluation of the effect of vitamin D supplementation on spermatogram, seminal and serum levels of oxidative stress indices in asthenospermia infertile men: a study protocol for a triple-blind, randomized controlled trial

BACKGROUND

It is suggested that vitamin D may have a beneficial role in male reproduction. The male reproductive system is a target tissue for vitamin D. This study will aim to evaluate the effects of vitamin D supplementation on sperm parameters, seminal and serum levels of oxidative stress and serum endocrine factors in asthenospermia infertile men.

METHODS/DESIGN

This randomized, triple-blind, placebo-controlled clinical trial will be conducted on 86 infertile men with idiopathic asthenozoospermia (the mobility of sperm < 40% and rapid progressive sperm motility < 32%), with serum levels of vitamin D less than 30 ng / ml in the "Infertility Clinic of Ahvaz Jahad daneshgahi", Iran.

MAIN OUTCOMES MEASURE (S)

Demographic data, dietary intake, physical activity, sun exposure, anthropometric indices, serum and seminal levels of MDA (Malondialdehyde), 8-hydroxy-2- Dioxy Guanosine (8-OHDG), Total Antioxidant Capacity (TAC) and calcium, sperm DNA fragmentation index (DFI), serum 25-OHD, luteinizing hormone (LH), follicle-stimulating hormone (FSH), total testosterone (T), estradiol (E2), sex hormone-binding globulin (SHBG), free androgen index (FAI = T/SHBG. 100), T/LH and T/E2 ratios, prolactin (PRO), parathyroid hormone (PTH), osteocalcin (OCN), phosphorus and sperm parameters.

DISCUSSION

The deficiency of vitamin D as an antioxidant is common all over the world. Numerous observational studies have shown a positive association between vitamin D levels and semen quality. However, few clinical studies have been conducted in this area. So considering with the high prevalence of this antioxidant deficiency specifically in infertile men, it seems that the supplementation of vitamin D in infertile men with insufficient levels or deficiency may improve the status of oxidative stress and thereby may affect sperm parameters and endocrine factors involved in male fertility.

TRIAL REGISTRATION

Iran Clinical Trials Registry, ID: IRCT20151128025274N4 , registered on 28 March 2018.

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 and reproductive health]

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

Impact of vitamin D on human embryo implantation-a prospective cohort study in women undergoing fresh embryo transfer

OBJECTIVE

To measure free and total 25-hydroxyvitamin D [25(OH)D] immediately before embryo transfer and analyze its association with early pregnancy outcome parameters such as biochemical pregnancy, implantation rate, and clinical pregnancy rates in women undergoing fresh embryo transfer after their first ovarian hyperstimulation.

DESIGN

Prospective cohort study.

SETTING

Academically affiliated private fertility center.

PATIENT(S)

A total of 2,569 women undergoing fresh embryo transfer after ovarian hyperstimulation.

INTERVENTIONS(S)

None.

MAIN OUTCOME MEASURE(S)

The study end points were biochemical pregnancy rate, implantation rate, clinical pregnancy rate, ectopic pregnancy rate, early miscarriages, and ongoing pregnancy rate. Free and total 25(OH)D concentrations were measured 1 day before embryo transfer.

RESULT(S)

Total 25(OH)D correlated with free 25(OH)D. Total and free 25(OH)D serum concentrations were similar in those patients reaching and not reaching the study outcomes (biochemical pregnancy rate, implantation rate, clinical pregnancy rate, ectopic pregnancy rate, early miscarriages, and ongoing pregnancy rate). There was likewise no statistical difference when analyzing the frequency of all study outcomes in quintiles of either total or free 25(OH)D. In addition, the study population was divided into three groups according to the total vitamin D status based on clinical practice guideline. All outcomes were similar in women with adequate, insufficient, and deficient total 25(OH)D. Multiple linear regression analysis considering confounding likewise indicated no association of free or total vitamin D with any of the study outcomes.

CONCLUSION(S)

Neither free nor total 25(OH)D concentration at embryo transfer was associated with successful embryo implantation in women undergoing fresh transfer after ovarian hyperstimulation.

Serum Vitamin D status is associated with increased blastocyst development rate in women undergoing IVF

RESEARCH QUESTION

To determine the relationship between vitamin D (VitD) status and embryological, clinical pregnancy and live birth outcomes in women undergoing IVF.

DESIGN

Cross-sectional, observational study conducted at a university-affiliated private IVF clinic. A total of 287 women underwent 287 IVF cycles and received a fresh embryo transfer. Patients had their serum 25-hydroxyvitamin D2/D3 (VitD) determined on the day of oocyte retrieval, which was analysed in relation to blastocyst development rate, clinical pregnancy and live birth outcomes.

RESULTS

In stepwise, multivariable logistic regression models, increases in blastocyst development rate, number and quality, along with embryo cryopreservation and utilization rates were associated with women with a sufficient VitD status (≥20 ng/ml). For a single increase in the number of blastocysts generated per cycle or embryos cryopreserved per cycle, the likelihood for the patient to be VitD sufficient was increased by 32% (odds ratio [OR] 1.32, 95% confidence interval [CI] 1.10-1.58, P = 0.002 and OR 1.33, 95% CI 1.10-1.60, P = 0.004, respectively). Clinical pregnancy (40.7% versus 30.8%, P = 0.086) and live birth rates (32.9% versus 25.8%, P = 0.195) in the sufficient VitD group versus the insufficient group were not significantly different and VitD sufficiency was not significantly associated with these outcomes.

CONCLUSION

A strong relationship was observed between blastocyst development and VitD sufficiency. However, there was no association between VitD and clinical pregnancy or live birth outcomes. Further larger studies are needed to investigate whether the observed effect on blastocyst development may have downstream implications on subsequent clinical pregnancy or live birth rates, and on a potential mechanism where sufficient VitD concentrations are linked to improved IVF outcomes.

How vitamin D level influences in vitro fertilization outcomes: results of a systematic review and meta-analysis

OBJECTIVE

To investigate the impact of serum vitamin D level on in vitro fertilization (IVF) outcomes.

DESIGN

Systematic review and meta-analysis.

SETTING

Not applicable.

PATIENTS

Infertile women undergoing conventional IVF or intracytoplasmic sperm injection (ICSI).

INTERVENTIONS

Systematic search of PubMed, MEDLINE, EMBASE, Global Health, The Cochrane Library, Health Technology Assessment Database, and Web of Science from inception until July 2019 with cross-checking of references from relevant articles in English. Vitamin D levels were categorized into three groups: deficient (<20 ng/mL), insufficient (20-30 ng/mL), and replete (>30 ng/mL). Before starting the data extraction, we registered the review protocol in PROSPERO (CRD42019134258).

MAIN OUTCOME MEASURES

We consider clinical pregnancy rate (CPR), live birth rate (LBR), and/or ongoing pregnancy rate (OPR) as primary outcomes. Likewise, the miscarriage rate was considered as a secondary outcome.

RESULTS

Primary analysis showed that women with a replete level of vitamin D had higher CPR and LBR/OPR compared to those with a deficient of insufficient level of vitamin D. However, sensitivity analysis led to non-significant differences between the comparators for CPR (odds ratio 0.71, 95% confidence interval 0.47-1.08, I2 = 61%) and OPR/LBR (odds ratio 0.78, 95% confidence interval 0.56-1.08], I2 = 61%). Also, for miscarriage a statistically different rate was not reached.

CONCLUSION

Serum vitamin D levels do not influence IVF outcomes in terms of CPR, LBR/OPR, and miscarriage rate. Future large cohort studies are warranted to determine whether the threshold of vitamin D affects reproductive outcomes. Currently, there is a lack of consensus between the appropriate vitamin D threshold to predict reproductive outcomes compared to the one established for bone health.

PROSPERO NUMBER

CRD42019134258.

Calcitriol Effect on Outcomes of in Vitro Fertilization in Infertile Women with Vitamin D Deficiency: A Double-Blind Randomized Clinical Trial

INTRODUCTION

Recent studies have addressed the role of micronutrients in fertilization, such as vitamin D. The present study aims to explore the effects of using calcitriol, an active form of vitamin D, on IVF results in women with vitamin D deficiency.

METHOD

This double-blinded randomized clinical trial was done on 180 infertile women, undergone IVF treatment. Out of them, 95 were found to have vitamin D deficiency (blood serum 25-dihydroxy vitamin D <30 ng/ml). Fifty one women in experimental group were treated with two 0.25 µg calcitriol pills daily during 4 weeks (discontinued 8 hours prior to the embryo transfer) and 44 subjects to the placebo group (mean vitamin D deficiency 27.5 ±1.8 in case group vs. 27.6±1.8 in control group, P>0.05). Final analysis includes outcomes of chemical and clinical pregnancy was done on 74 women (including 36 in case and 38 in control group).

RESULTS

Our study showed that in the experimental group, chemical pregnancy success was significantly higher than that in the control group, 31.4 vs. 18.2% (P<0.05). However, there were no significant differences between the 2 groups in reaching the clinical pregnancy stage (25.5% in case group vs. 13.6% in control group) and continuation of pregnancy into week 20 (9.8% in case group vs. 11.6% in control group) (P>0.05).

CONCLUSION

Calcitriol administration by improving the implantation process can significantly increase the chances of successful IVF cycle results in infertile women with vitamin D deficiency.

Assessing endometrial receptivity after recurrent implantation failure: a prospective controlled cohort study

RESEARCH QUESTION

What is the prevalence of disrupted markers of endometrial function among women experiencing recurrent implantation failure (RIF), and does the prevalence differ from a control cohort?

DESIGN

Prospective controlled cohort study. In total, 86 women with a history of RIF and 37 women starting their first fertility treatment were recruited for this study. Endometrial and blood profiling were carried out in a hormone-substituted cycle using oestradiol and progesterone. Endometrial biopsies were analysed by histology, immune cell profiling, and the endometrial receptivity array (ERA®) test (Igenomix, Valencia, Spain). The vaginal microbiome was analysed using a NGS-based technology (ArtPRED, Amsterdam, the Netherlands). Blood tests included oestradiol, progesterone, prolactin, thyroid-stimulating hormone, vitamin D and anti-phospholipid antibody levels.

RESULTS

Patients who had experienced RIF produced a range of test abnormalities. Compared with controls, women with RIF had a higher prevalence of chronic endometritis (24% versus 6%), a lower vitamin D level and a borderline lower progesterone level. Women who had experienced RIF had a more favourable vaginal microbiome compared with controls. Although the RIF cohort was older than the controls (mean age 33.8 years versus 30.2 years), no differences between the groups were observed in immune cell profiling and the ERA test.

CONCLUSION

These data demonstrate that a single test or treatment for the endometrial factor in RIF is unlikely to be clinically effective. Diagnosing the endometrium in women with RIF permits targeted rather than blind interventions. Relative vitamin D deficiency, lower mid-luteal progesterone and chronic endometritis are ready targets for treatment. Understanding the role and treatment of an unfavourable vaginal microbiome in RIF needs further investigation.

Relationship between nutrition and reproduction

BACKGROUND

Recently, the relationship between nutrition and reproduction is being studied. In particular, when older women receive reproductive treatment, egg aging causes greater problems than organic factors.

METHODS

This study investigated the relationship between nutrition and reproduction with a focus on factors that cause aging, including oxidation, glycation, and chronic inflammation. A large volume of data concerning each nutrient's relationship with reproductive medicine was collected from a number of observational studies.

MAIN FINDINGS

The results showed that refined carbohydrates should be avoided and care should be taken to achieve proper intake of omega-3 fatty acids. Folic acid and vitamin D were also effective. For men, antioxidant measures are especially effective. The effects of antioxidants are related to insulin resistance, which causes chronic inflammation.

CONCLUSION

Recent research has shown that rather than meal content, meal intervals are more important for improving insulin resistance. Future research should examine lifestyle-related nutrition factors and their relationships to reproductive treatment.

Relation of serum vitamin D level in polycystic ovarian syndrome (PCOS) patients to ICSI outcome

Background

Recently, vitamin D was discovered to have an important role in female reproduction and IVF. However, there were no studies specifically addressed its role in polycystic ovarian syndrome (PCOS) patients undergoing ICSI cycles. Therefore, this cross-sectional study in a university hospital was conducted to evaluate the effect of serum level of vitamin D (VD) on the number of retrieved and fertilized oocytes, and chemical and clinical pregnancy rate in PCOS females undergoing ICSI cycles. The study included 80 PCOS cases undergoing ICSI cycles in the age from 20 to 39 years using antagonist protocol. Cases with severe male or tubal factors were excluded. Serum 25 (OH) D vitamin level was assessed by the ELIZA method on the day of oocyte retrieval. Correlation and regression analyses were used in the analysis.

Results

VD was positively correlated to both numbers of retrieved and fertilized oocytes (r = 0.35, 95% CI 0.15, 0.53, P = 0.001; r = 0.33; 95% CI 0.03, 0.57, P = 0.03, respectively). It was still significantly correlated to the number of oocytes (coefficient 0.47; 95% CI 0.1, 0.9; P = 0.018) and to the number of fertilized eggs (coefficient 0.3; 95% CI 0.02, 0.58; P = 0.03) after adjusting for age, BMI, and type of ovulation-triggering agent. This means with each 2 ng/mL increase in serum VD level, around one more egg will be retrieved. In addition, there will be one more fertilized oocyte with each 3 ng/mL increase in the vitamin level. However, no significant correlation was found between the vitamin level and the occurrence of chemical or clinical pregnancy.

Conclusions

Serum vitamin D level is positively correlated with the number of retrieved and fertilized oocytes in PCOS patients undergoing ICSI cycles.

Roles of Vitamin D in Reproductive Systems and Assisted Reproductive Technology

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

Characterization of VDR and CYP27B1 expression in the endometrium during the menstrual cycle before embryo transfer: implications for endometrial receptivity

BACKGROUND

Molecular analyses of vitamin D in a typical cycling endometrium has received minimal research attention in the reproductive field. This study was designed to assess how expression of the endometrial vitamin D receptor (VDR) and CYP27B1, a vitamin D metabolizing enzyme, change during the menstrual cycle in women of reproductive age. In addition, this study explores the association between expression of vitamin D-VDR system and endometrial receptivity during the implantation window.

METHODS

Sixteen patients underwent standardized in vitro fertilization (IVF) treatment and freeze-all techniques. Before embryo transfer, total serum 25(OH) D levels were determined through blood samples and VDR, CYP27B1, HOXA10, and CYP19 expression were determined through endometrial samples. Endometrial receptivity was also assessed using an electron microscope.

RESULTS

We found that VDR protein expression was significantly lower throughout the endometrial secretory phase compared to the proliferative phase, while CYP27B1 expression remained constant during the menstrual cycle. During the implantation window, ultrastructural evaluation showed that higher serum vitamin D levels were associated with more mature pinopodes; VDR and HOXA10 protein expression were substantially elevated in pregnant women compared to non-pregnant women; and VDR protein levels were positively correlated with HOXA10 levels. In addition, serum vitamin D levels were positively correlated with VDR and HOXA10 protein levels in the endometrium.

CONCLUSIONS

Women with increased VDR expression in the endometrium, especially during the implantation window of the menstrual cycle, were significantly more likely to be pregnant than women with decreased expression. Our results support the hypothesis that the Vitamin D-VDR system performs a role during the development of endometrial receptivity.

Effect of 1,25(OH)2-vitamin D3 on expression and phosphorylation of progesterone receptor in cultured endometrial stromal cells of patients with repeated implantation failure

Repeated implantation failure (RIF) occurs in a condition when good quality embryos fail to implant in the endometrium following several in vitro fertilization (IVF) cycles. Suboptimal endometrial receptivity is one of the main underlying factors that causes this failure. Progesterone is the key regulator of endometrial receptivity which regulates gene expression through binding to its receptors in the endometrial stromal cells (eSC). The aim of this study was to evaluate the effect of 1,25(OH)2-vitamin D3 on progesterone receptor (PR) expression level and its phosphorylation on Ser294 residues in eSC of RIF patients and healthy fertile women. After isolation of the eSC from biopsy samples of RIF patients and healthy fertile women and their characterization, the cells were incubated with vitamin D3 and the expression level of PR mRNA, PR protein and phospho-Ser294 PR protein were evaluated after treatment. The results showed that vitamin D3 treatment increases PR mRNA and protein level and phospho-Ser294 PR protein level in the isolated eSC of both RIF patients and the control group. These results suggest that vitamin D3 may possibly play a key role during the embryo implantation process by affecting the expression pattern and regulatory modifications of the PR in the eSC.

Vitamin D in Follicular Fluid Correlates With the Euploid Status of Blastocysts in a Vitamin D Deficient Population

CONTEXT

The widespread distribution of the Vitamin D (VitD) receptor in reproductive tissues suggests an important role for VitD in human reproduction. The assessment of patient´s VitD is based on the 25-hydroxyvitamin D (25(OH)D) metabolite measurement. However, most of the circulating 25(OH)D is bound to either VitD-binding protein (VDBP) (88%) or albumin (12%) and less than 1% circulates free.

OBJECTIVE

To determine a possible correlation between VitD levels in serum (S) and follicular fluid (FF) and blastocyst ploidy status in patients undergoing infertility treatment.

METHODS

A prospective observational study was performed including couples planned for preimplantation genetic testing for aneuploidies (PGT-A) from ART Fertility Clinics. Patients were classified according to their 25(OH)D-Serum levels: VitD deficient group <20 ng/ml and insufficient/replete ≥20 ng/ml defined as VitD non-deficient group.

RESULTS

Serum samples and 226 FF from individual follicles were collected for 25(OH)D, bioavailable 25(OH)D, free 25(OH)D, and % free 25(OH)D measurement. 25(OH)D-Serum in VitD deficient and non-deficient were 13.2±4.0 ng/ml vs 32.3±9.2 ng/ml; p<0.001. FF from 40 and 74 biopsied blastocysts was analysed of which 52.5 and 60.8% were euploid (p = 0.428), respectively. In VitD deficient patients, mean 25(OH)D-FF, bioavailable 25(OH)D-FF, and free 25(OH)D-FF were higher in euploid vs aneuploid blastocysts (18.3±6.3 ng/ml vs 13.9±4.8 ng/ml; p = 0.040; 1.5±0.5 ng/ml vs 1.1±0.4 ng/ml; p = 0.015; 0.005±0.002 ng/ml vs 0.003±0.001 ng/ml; p = 0.023, respectively), whilst no differences were found in VitD non-deficient patients (37.9±12.3 ng/ml vs 40.6±13.7 ng/ml; p = 0.380; 3.1±1.1 ng/ml vs 3.3±1.2 ng/ml; p = 0.323; 0.01±0.003 ng/ml vs 0.01±0.004 ng/ml; p = 0.319, respectively).

CONCLUSION

VitD non-deficient patients have a significantly higher probability of obtaining a euploid blastocyst compared to VitD deficient patients (OR:33.36, p = 0.002).

Effect of a 6-week "Mediterranean" dietary intervention on in vitro human embryo development: the Preconception Dietary Supplements in Assisted Reproduction double-blinded randomized controlled trial

OBJECTIVE

To study the impact of increased dietary intake of omega-3 fatty acids, vitamin D, and olive oil for 6 weeks before in vitro fertilization (IVF) or IVF-intracytoplasmic sperm injection (ICSI) on morphokinetic markers of early embryo development.

DESIGN

A double-blinded randomized controlled trial.

SETTING

Academic IVF unit.

PATIENT(S)

A total of 111 couples undergoing IVF or IVF-ICSI were recruited.

INTERVENTIONS(S)

Fifty-five couples received the 6-week study intervention of a daily supplement drink enriched with omega-3 fatty acids and vitamin D plus additional olive oil and olive oil-based spread, and 56 couples received the control intervention.

MAIN OUTCOME MEASURE(S)

The primary end point for the study was the time taken for completion of the second cell cycle after fertilization (CC2). Secondary end points included time to complete the third and fourth cell cycles (CC3 and CC4), the synchrony of the second and third cell cycles (S2 and S3), and the day 3 and day 5 Known Implantation Data Scores (KIDScores).

RESULT(S)

There was no difference in CC2 between the two groups. However, CC4 was accelerated in the study group compared with the control group, and a significantly shortened S3 as well as an increase in KIDScore on day 3 were observed, indicating improved embryo quality in the study group.

CONCLUSION(S)

This study demonstrates that a short period of dietary supplementation alters the rate of embryo cleavage. Further research is required to investigate the mechanisms that regulate this effect, and whether the impact on embryo development translates into improved clinical outcomes.

CLINICAL TRIAL REGISTRATION NUMBER

ISRCTN50956936.

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

STUDY QUESTION

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

SUMMARY ANSWER

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

WHAT IS KNOWN ALREADY

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

STUDY DESIGN, SIZE, DURATION

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

PARTICIPANTS/MATERIALS, SETTING, METHODS

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

MAIN RESULTS AND THE ROLE OF CHANCE

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

LIMITATIONS, REASONS FOR CAUTION

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

WIDER IMPLICATIONS OF THE FINDINGS

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

STUDY FUNDING/COMPETING INTEREST(S)

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

TRIAL REGISTRATION NUMBER

N/A.

Vitamin D, reproductive disorders and assisted reproduction: evidences and perspectives

Vitamin D is an important nutrient involved in many fundamental health outcomes. However, its influence on female reproductive function remains ambiguous. Cholecalciferol seems to have a role in the reproductive processes and in the patients affected by polycystic ovary syndrome, endometriosis, uterine myomas and premature ovarian failure. Moreover, it may play an important role in the assisted reproductive techniques, given that it is capable of influencing oocyte quality, but also an adequate preparation of the endometrium for embryonic implantation. Although promising, available evidence is based on a limited number of in vitro, in vivo and clinical studies. We provide an overview of the association between vitamin D and female infertility reporting the most recent data published in the literature. Nevertheless, properly randomised clinical trials are mandatory to achieve more conclusive results about the promising role of vitamin D in the management of female assisted reproduction.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Vitamin D and assisted reproductive treatment outcome: a prospective cohort study

Background

Vitamin D deficiency has been associated with an increased risk of abnormal pregnancy implantation leading to obstetric complications such as pre-eclampsia and fetal growth restriction. However, the effect of vitamin D on reproductive treatment outcomes in couples undergoing assisted reproductive treatment is poorly understood. This study investigates the association between vitamin D and reproductive treatment outcomes in women undergoing assisted reproductive treatments?

Methods

A prospective cohort study conducted at a large tertiary teaching hospital, United Kingdom. Five hundred women undergoing assisted reproductive treatment were recruited between September 2013 and September 2015. All participants had their serum vitamin D measured and their reproductive treatment outcomes collated. Women were categorised in to three groups: vitamin D replete (> 75 nmol/L), insufficient (50-75 nmol/L) and deficient (< 50 nmol/L) according to Endocrine Society guidance. The primary outcome was live birth. Secondary outcomes included biochemical pregnancy, clinical pregnancy and pregnancy loss rates.

Results

Vitamin D deficiency was found in 53.2% (266/500) of participants and vitamin D insufficiency was found in 30.8% (154/500) of participants. Only 16% (80/500) of women were vitamin D replete. The live birth rates for vitamin D deficient, insufficient and replete women were 23.2% (57/246), 27.0% (38/141) and 37.7% (29/77) respectively (p = 0.04). The respective live birth rates for vitamin D deficient, insufficient and replete women were 24.3, 27.1, 34.4% after adjustment for key prognostic factors (p = 0.25).

Conclusions

Vitamin D deficiency and insufficiency are common in women undergoing assisted reproductive treatments. The crude live birth rate achieved in women undergoing assisted reproductive treatments are associated with serum vitamin D, although statistical significance is lost when adjusting for important prognostic variables. Vitamin D deficiency could be an important condition to treat in women considering fertility treatment. A research trial to investigate the benefits of vitamin D deficiency treatment would test this hypothesis.

Trial registration

Clinicaltrials.gov - NCT02187146.

Electronic supplementary material

The online version of this article (10.1186/s12978-019-0769-7) contains supplementary material, which is available to authorized users.

A shift in follicular fluid from triacylglycerols to membrane lipids is associated with positive pregnancy outcome

Follicular fluid (FF) is a liquid that surrounds the ovum. Its metabolite and, specifically, its lipid content have been associated with oocyte development. To characterize possible association between the lipid composition of FF and the outcome of pregnancy, we carried out a lipidomics study and compared the abundance of lipids from FF of patients with positive and negative outcomes. We found a differential lipid network wiring in positive-outcome FF, with a significant decrease (∼2 fold; P < 0.001) in triacylglycerol levels and higher accumulation (10-50%; P < 0.001) of membrane lipids groups (phospholipids and sphingolipids). In addition to this major metabolic alteration, other lipid groups such as cholesteryl esters showed lower levels in positive-outcome patients, whereas derivatives of vitamin D were highly accumulated in positive-outcome FF, supporting previous studies that associate vitamin D levels in FF to pregnancy outcome. Our data also point to specific lipid species with a differential accumulation pattern in positive-outcome FF that predicted pregnancy in a receiver operating characteristic analysis. Altogether, our results suggest that FF lipid network is associated with the oocyte development, with possible implications in diagnostics and treatment.-Shehadeh, A., Bruck-Haimson, R., Saidemberg, D., Zacharia. A., Herzberg, S., Ben-Meir, A., Moussaieff, A. A shift in follicular fluid from triacylglycerols to membrane lipids is associated with positive pregnancy outcome.

High prevalence of vitamin D deficiency in Turkish women undergoing in vitro fertilization: A descriptive study

The authors' aim in this study was to determine the vitamin D levels of Turkish women who were undergoing in vitro fertilization (IVF). The study design was a descriptive cohort study of a total of 208 infertile women at an IVF center in Turkey. Our findings showed that 4.3% of the women had a replete vitamin D level, 23.6% of the women had insufficient vitamin D levels, and 72.1% of women had deficient vitamin D levels. Our findings suggest that much more effective vitamin D support programs should be implemented for women who are seeking to become pregnant.

Diet and female fertility: doctor, what should I eat?

Fecundity is the capacity to produce offspring. Identifying dietary factors that influence human fecundity is of major clinical and public health significance. This review focuses on the evidence from epidemiologic literature for the relationships between key nutritional factors and female reproductive potential. According to existing data, women trying to achieve pregnancy are encouraged to increase consumption of whole grains, omega-3 fatty acids, fish, and soy and to reduce consumption of trans fats and red meat. In addition, a daily multivitamin that contains folic acid before and during pregnancy may not only prevent birth defects, but also improve the chance of achieving and maintaining a pregnancy. In contrast, there is limited evidence supporting an association between vitamin D and human fecundity outcomes despite promising evidence from nonhuman studies. Questions for future research included the roles of other types of fat (especially omega-6 and monounsaturated fats) and protein (especially white meat and seafood) on female fertility; particular attention should also be paid to exposure to environmental contaminants in foods. Although much work remains, this review accrued best available evidence to provide practical dietary recommendations for women trying to conceive.