Effect of Vitamin D Supplementation on Intracytoplasmic Sperm Injection Outcomes: A Randomized Double-Blind Placebo-Controlled Trial

Association between oxidative balance score and female infertility from the national health and nutrition examination survey 2013-2018

Background

The correlation between oxidative stress and female infertility pathogenesis was established, and the oxidative balance score (OBS) can serve as a measure of overall oxidative stress burden within an individual. Prior reports have not addressed the relationship between OBS and female infertility. This study endeavors to investigate the association between infertility risk in female and OBS.

Methods

The analysis focused on data from the National Health and Nutrition Examination Survey 2013-2018. OBS was determined from 16 dietary components and 4 lifestyle components. Multivariate logistic regression was employed to investigate the relationship between OBS and female infertility. Further stratified analysis was conducted to examine the associations across various subgroups. To elucidate the dose-response relationship between infertility risk in female and OBS, a restricted cubic spline function was employed.

Results

The study included a total of 1410 participants. Through weighted multivariable logistic regression analysis, we observed a consistent inverse correlation between OBS and the risk of female infertility [OR (95% CI) = 0.97 (0.95, 0.99), p = 0.047]. When participants were segregated into quartiles based on OBS, those in the highest quartile had a 61% [OR (95% CI) = 0.39 (0.2, 0.79), p = 0.01] reduced risk of infertility compared to those in the lowest quartile of OBS. A trend test assessing OBS by quartile also revealed the relationship between OBS and female infertility. This correlation remained constant across both dietary and lifestyle OBS. Additionally, lifestyle OBS and female infertility exhibited a nonlinear association. A sensitivity analysis verified the consistency of our findings.

Conclusion

The study found that a higher OBS is associated with a lower prevalence of female infertility. These results emphasized the potential role of oxidative homeostasis in the pathogenesis of infertility and highlighted the importance of follow-up studies and prevention strategies.

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.

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.

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 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.

Vitamin D Supplementation Improves Uterine Receptivity in a Rat Model of Vitamin D Deficiency: A Possible Role of HOXA-10/FKBP52 Axis

Synchronized uterine receptivity with the time of implantation is crucial for pregnancy continuity. Vitamin D (VD) deficiency has been linked to the failure of implantation. Therefore, we tested the link between the Homeobox transcription factor-10/immunophilin FK506-binding protein 52 (HOXA-10/FKBP52) axis and the uterine receptivity in VD-deficient rats. The effect of VD supplementation at different doses was also investigated. Forty-eight pregnant rats were divided into six groups (eight/group); normal control rats fed with standard chow (control), control rats supplemented with VD (equivalent dose of 400 IU/day) (control-D400). VD-deficient group (DEF) and the three VD deficiency groups with VD supplementation were equivalent to 400, 4,000, and 10,000 IU/day (DEF-D400, DEF-D4000, and DEF-D10000, respectively). The expression levels of HOXA-10/FKBP52, progesterone level, and histological evaluation of decidualization using osteopontin (OSN) and progesterone receptor (PGR) were estimated. An assessment of the uterine contractility was conducted for all rats. This study showed the downregulation of HOXA-10/FKBP52 together with increased amplitude and frequency of the uterine contractility in the DEF group compared to control. VD dose-dependent supplementation restored progesterone/receptor competency, upregulated the expressional response of HOXA-10 and its downstream FKBP52, and improved uterine receptivity and endometrial decidualization at the time of implantation that was documented by increased area% of OSN and the number of implantation beads.

The Effect of Vitamin D Deficiency on Overgrowth of Uterine Fibroids: A Blinded Randomized Clinical Trial

Background

To evaluate the effects of vitamin D (vitD) supplement on uterine fibroid growth.

Materials and Methods

A randomized blinded clinical trial was conducted at a tertiary university-based hospital from August 2017 to September 2018. Totally, 204 women were enrolled into the study. They had at least one uterine fibroid >10 mm on transvaginal ultrasound and their vitD level was insufficient (i.e. 20-30 ng/ml). The intervention group was treated with vitD 50000 U supplements for two months. After 2 months, ultrasound screening and vitD level measurement was done in both groups.

Results

At first, the mean serum vitD levels in intervention and control group were 23.62 and 23.20 ng/ml, respec- tively. After 8 weeks, the mean serum vitD levels in the control and intervention group were 22.72 and 28.56 ng/ml respectively (P<0.05). Also, mean fibroma diameter in the intervention group before and after 8 weeks of vitD supple- mentation was 43 ± 4.68 and 42.6 ± 1.31 mm, respectively. Mean uterine fibroid diameter in the control group which did not receive vitD supplements, before and after 8 weeks was 41.98 ± 5.25 and 47.81 ± 3.42 mm, respectively. The variation in the mean size of the uterine fibroid between the control and intervention group which was respectively about 5.83 mm increase and 0.48 mm decrease, was significant (P<0.001).

Conclusion

Our results showed that vitD supplementation prevents fibroid growth. It seems that vitD supple- ment is a simple, safe and inexpensive modality for leiomyoma growth prevention (Registration number: IRCT201703122576N15).

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.

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.

Vitamin D and Obesity: Two Interacting Players in the Field of Infertility

Obesity plays an important role in human fertility in both genders. The same is true for vitamin D, for which accumulating evidence from observational human studies suggests a key role for both male and female fertility. In the latter case, however, robust data from relevant interventional studies are currently lacking. It is also not clear whether obesity and vitamin D deficiency, besides their independent effect on human infertility, act in synergy. Several pathogenetic mechanisms may be proposed as a linkage between vitamin D deficiency and obesity, with respect to infertility. In any case, the independent contribution of vitamin D deficiency in obese infertile states needs to be proven in interventional studies focusing on either vitamin D supplementation in obese or weight loss strategies in vitamin D-deficient infertile patients.