Lower plasma 25-hydroxyvitamin D is associated with irregular menstrual cycles in a cross-sectional study

Vitamin D status and supplementation, calcium supplementation, and timing of natural menopause

Vitamin D status has been inconsistently associated with ovarian reserve and menopause. We used data from the Sister Study cohort to examine the associations of vitamin D supplement use, total 25-hydroxyvitamin D (25OHD) level, and calcium supplement use with the timing of natural menopause. Vitamin D and calcium supplement use were assessed on a questionnaire at baseline (mean age: 46) and two follow-up time points, and characterized in multiple ways based on type, dose, and duration of use. Serum samples from a random subset of participants were analyzed for total 25OHD (25OHD3 + 25OHD2 + epi-25OHD3) using liquid chromatography-mass spectrometry. Menopause was assessed at each yearly follow-up with the question "Have you had a menstrual period in the past 12 months?"; if the response was "no", age at last menstrual period was recorded. We censored women at time of hysterectomy or medically induced menopause, death, loss to follow-up or October 2020. We used multivariable Cox proportional hazard models with age as the time scale to estimate hazard ratios (HRs) and 95 % confidence intervals (CIs), adjusting for race/ethnicity, education, body mass index, alcohol use, smoking status, and physical activity. Among the 13,102 eligible premenopausal participants, 8897 experienced natural menopause during follow-up. Concomitant use of a multivitamin and a vitamin D supplement was associated with slightly earlier menopause (HR(CI): 1.10 (0.98, 1.24)). None of the remaining vitamin D or calcium supplement variables (alone or in combination) were meaningfully associated with timing of natural menopause. In a subsample with 25OHD measurements (n = 906), neither total 25OHD nor 25OHD3 was associated with timing of menopause. Our study includes, on average, 6 years of follow-up from an average age of 46 years and did not find associations between vitamin D or calcium supplement use and timing of menopause. Future studies should focus on a life course approach to this question and include 25OHD measures from early mid-life when examining menopause timing.

Characteristics of the hormonal background in women with abnormal uterine bleeding and extragenital disorders

OBJECTIVE

Aim: To establish the peculiarities of the hormonal background in women with abnormal uterine bleeding and extragenital disorders.

PATIENTS AND METHODS

Materials and Methods: The study involved examination of 100 women of reproductive age with concomitant ED and AUB (MG). CG included 50 healthy women. MG women were additionally divided into subgroups depending on the detected pathological changes in the uterine cavity. When examining the hormonal status, concentrations of FSH, LH, estradiol, progesterone, and leptin in BS were determined. Additionally, the level of 25-hydroxyvitamin D ((25-OH) D) was determined.

RESULTS

Results: The decrease in FSH level in subgroups of GP, PSL, EH, EHL was 1.8-2.4 times (KWT, p<0.01). LH in BS of MG patients was statistically lower than that of CG patients (MWT, p=0.0083). The lowest level of LH was registered in patients with EHL, which was 2 times lower than this indicator in CG. A statistically significant increase in the level of estradiol was registered in 73% of MG patients (MWT, p=0.044). The lowest level of progesterone was registered in patients with EHL - 8.40, which is 4.7 times lower than in CG (MWT, p=0.0021). A statistically significant increase in the level of leptin in BS was observed in MG patients (KWT, p=0.0021). The highest level of leptin was found in women with AFP, 2.3 times higher than CG indicators. A statistically significant correlation between the level of leptin and BMI (r=0.86, p=0.011) and a statistically significant (p=0.023) correlation between the level of leptin and estradiol in BS of patients of the examined groups (r=0.42) were revealed. In 87% of MG women, vitamin D deficiency was observed in BS (KWT, p=0.03). A statistically significant (p=0.01) negative correlation between the level of estradiol and vitamin D in the BS of female patients was revealed (r=-0.61, p=0.01).

CONCLUSION

Conclusions: Women of reproductive age with AUB and ED were found to have disorders in the hypothalamic-pituitary-ovarian system. Most patients are characterized by an elevated level of leptin, the concentration of which is closely correlated with BMI, and an elevated level of estradiol is correlated with the level of vitamin D.

Evidence-Based Approach for Secondary Prevention of Uterine Fibroids (The ESCAPE Approach)

Uterine fibroids (UFs) are common tumors in women of reproductive age. It is imperative to comprehend UFs' associated risk factors to facilitate early detection and prevention. Simple relying on surgical/pharmacological treatment of advanced disease is not only highly expensive, but it also deprives patients of good quality of life (QOL). Unfortunately, even if the disease is discovered early, no medical intervention is traditionally initiated until the disease burden becomes high, and only then is surgical intervention performed. Furthermore, after myomectomy, the recurrence rate of UFs is extremely high with the need for additional surgeries and other interventions. This confused approach is invasive and extremely costly with an overall negative impact on women's health. Secondary prevention is the management of early disease to slow down its progression or even halt it completely. The current approach of watchful observation for early disease is considered a major missed opportunity in the literature. The aim of this article is to present an approach named the ESCAPE (Evidence-Based Approach for Secondary Prevention) of UF management. It comprises simple, inexpensive, and safe steps that can arrest the development of UFs, promote overall reproductive health, decrease the number of unnecessary surgeries, and save billions of health care systems' dollars worldwide.

Serum 25-hydroxyvitamin D levels and the risk of idiopathic central precocious puberty in girls

INTRODUCTION

Prior studies have found inconsistent results regarding the relationship between vitamin D status and Idiopathic Central Precocious Puberty (ICPP).

OBJECTIVE

To assess the role of serum 25-hydroxyvitamin D (25 [OH]D) levels in ICPP development.

METHOD

The authors retrospectively collected data from 221 girls with ICPP and 144 healthy girls between January 2017 and December 2019. The participants' serum 25(OH)D levels were measured using an automatic chemiluminescence method, and the association between serum 25(OH)D levels and the risk of ICPP was assessed using multivariate logistic regression analysis. Odds Ratios (OR) with 95% Confidence Intervals (95% CI) were calculated as effect estimates.

RESULTS

Serum 25(OH)D levels in the ICPP group were significantly lower than those in healthy controls (p < 0.001). Multivariate analysis indicated that girls with insufficient vitamin D levels (OR = 0.201; 95% CI 0.094-0.428; p < 0.001) and sufficient vitamin D levels (OR = 0.141; 95% CI 0.053-0.375; p < 0.001) both had a lower risk of ICPP than girls with vitamin D deficiency. Moreover, the authors found that the height (p = 0.014), weight (p = 0.014), breast stage (p = 0.010), mother's height (p < 0.001), and luteinizing hormone/follicle-stimulating hormone ratio (p = 0.010) in girls with ICPP could be associated with levels of vitamin D.

CONCLUSION

This study found that a low serum 25(OH)D level is an independent risk factor for ICPP, and several characteristics of girls with ICPP could be affected by their vitamin D status.

Evaluation of biochemical variables in patients with recurrent aphthous stomatitis

PURPOSE

We investigated the effects of various biochemical agents on the etiopathogenesis of recurrent aphthous stomatitis (RAS).

METHODS

We enrolled 70 RAS patients and 70 healthy volunteers. Peripheral venous blood samples were collected. We performed complete blood counts, then measured the levels of ferritin, vitamin B12, iron, magnesium, phosphorus, calcium, thyroid-stimulating hormone, T3, T4, and 25-hydroxy D3.

RESULTS

The groups did not differ in terms of age (p = 0.912) or sex (p = 0.612). The levels of ferritin and 25-hydroxy vitamin D were significantly lower in RAS patients (both p ˂ 0.05).

CONCLUSION

Vitamin D and/or ferritin deficiency may induce RAS. Measurements of vitamin D and ferritin may assist diagnosis and follow-up.

Serum fat-soluble vitamins and the menstrual cycle in women of childbearing age

Evidence suggests that fat-soluble vitamins are involved in reproduction, but their association with the menstrual cycle, the proxy of female fecundity, remains largely unexplored in women of childbearing age. Serum fat-soluble vitamin levels were measured by HPLC-MS/MS and menstrual cycle data were acquired from 3123 women of reproductive age in Nanjing, China, using standard questionnaires. Irregular and long menstrual cycles occurred in 725 (23.2%) and 604 (19.3%) participants, respectively. Participants with higher levels of vitamins A and K had increased odds of irregular menstrual cycles (vitamin A: OR = 1.39 (95% CI: 1.12, 1.74); vitamin K: OR = 1.41 (95% CI: 1.13, 1.76)) and long menstrual cycles (vitamin A: OR = 1.34 (95% CI: 1.06, 1.69); vitamin K: OR = 1.27 (95% CI: 1.00, 1.61)), and the relationship showed a linear dose-response pattern (P-overall < 0.05, P-nonlinearity > 0.05). Vitamin A was positively associated with the average menstrual cycle length (β: 1.83, 95% CI: 0.28, 3.39). Vitamins A and K were interacted in their associations with irregular menstrual cycles and long cycles. In sensitivity analysis with further exclusion of participants with abnormal thyroid function or a history of polycystic ovary syndrome (PCOS), the association of vitamins A and K with the menstrual cycle remained robust. This study indicates that higher serum vitamin A and K levels in women of childbearing age are significantly associated with higher odds of irregular and long menstrual cycles with a linear dose-response curve. Further investigations are warranted to determine the appropriate fat-soluble vitamin levels for women of childbearing age.

Correlation between Serum 25-Hydroxyvitamin D Level and Depression among Korean Women with Secondary Amenorrhea: A Cross-Sectional Observational Study

Vitamin D deficiency is considered a major public health problem worldwide and has been reported as having an association with depression. However, studies on the association between vitamin D deficiency and depressive symptoms in secondary amenorrhea (SA) patients are still scarce. This study examined the relationship between serum 25-hydroxyvitamin D (25(OH)D) levels and depressive symptoms among Korean women with SA. In this cross-sectional observational study, 78 patients with SA were initially recruited. Clinical and biochemical parameters, including serum 25(OH)D level, were measured. Data from 63 SA patients who met the study inclusion criteria and completed psychiatric assessments were finally analyzed. We analyzed their association with depression using a hierarchical regression model. The average serum 25(OH)D level was 34.40 ± 24.02 ng/mL, and 41.3% of the women with SA were vitamin D-deficient (<20 ng/mL). The total score of the Korean version of the Hamilton Depression Rating Scale (K-HDRS) was negatively related to serum 25(OH)D levels, free testosterone, and serum anti-Müllerian hormone (AMH) after adjusting for age and BMI (r = −0.450, p < 0.001; r = −0.258, p = 0.045; and r = −0.339, p = 0.006, respectively). Serum 25(OH)D levels and AMH levels were the most powerful predictors of depressive severity when using the K-HDRS in SA patients (β = −0.39, p < 0.005; β = −0.42, p < 0.005, respectively). This study showed that low serum 25(OH)D levels were associated with the severity of depressive symptoms in SA patients. This observation suggests that the evaluation of vitamin D deficiency for the risk of depression may be necessary in patients with SA.

Association between serum 25-hydroxy vitamin D level and menstrual cycle length and regularity: A cross-sectional observational study

Background

Research examining the role of vitamin D deficiency and the development of menstrual disorders in women is of widespread interest. Studies have been published showing that supplementation with high-dose vitamin D can lead to the restoration of the menstrual cycle. We lack adequate information regarding the effect of vitamin D levels on the physiology of menstruation and further on fertility in women of reproductive age due to the contradictory results reported by studies.

Objective

To study the association of 25-hydroxy vitamin D with menstrual cycle characteristics including long and short cycle length and cycle irregularity.

Materials and Methods

In this cross-sectional study, serum vitamin D levels of 166 women attending an outpatient department with menstrual irregularities after excluding all obvious causes of menstrual disorders (n = 83) between April-June 2019 were measured and were compared with women of similar profiles with complaints other than menstrual irregularities (n = 83).

Results

A decreased level of vitamin D was associated with a 13.3 times odds of an irregular cycle (OR (95% CI): 13.30 (5.79-30.60), p < 0.001). 25-hydroxy vitamin D was not associated with age or body mass index. We found a significant difference (p < 0.001) in mean vitamin D levels among the females with irregular cycles vs. regular cycles.

Conclusion

Vitamin D plays a role in the physiology of reproduction specific to the menstrual cycle and ovulation. Long-term prospective studies assessing the exact cutoff value and the exact dose of supplementation required are needed.

Ultraviolet radiation and age at natural menopause in a nationwide, prospective US cohort

BACKGROUND

Solar ultraviolet radiation (UV) is a critical environmental factor for dermal conversion of vitamin D, which is suggested to support reproductive health. However, current epidemiological studies have reported conflicting results on the associations between vitamin D levels and ovarian reserve. Further, few studies have considered UV exposure and reproductive aging, which is closely related to declined ovarian reserve.

OBJECTIVES

We sought to examine the associations of long-term UV exposure and age at natural menopause in a large, nationwide, prospective cohort.

METHODS

Participants in the Nurses' Health Study II (NHS II) who were premenopausal at age 40 were included and followed through 2015. Erythemal UV radiation from a high-resolution geospatial model was linked to the participants' residential histories. Early-life UV was estimated using the reported state of residence at birth, age 15, and age 30. We used time-varying Cox proportional hazards models to estimate the hazard ratio (HR) and 95% confidence intervals (CIs) for natural menopause, adjusting for potential confounders and predictors of menopause.

RESULTS

A total of 63,801 women reported natural menopause across the 1,051,185 person-years of follow-up among 105,631 eligible participants. We found very modest associations with delayed menopause for long-term UV exposure (adjusted HR comparing highest to lowest quartile of cumulative average UV: 0.96, 95% CI: 0.94, 0.99). There was a suggestive inverse association between UV at age 30 with menopause (adjusted HR comparing highest to lowest quartile: 0.97, 95% CI: 0.95, 1.00) but not with UV at birth and age 15.

CONCLUSIONS

Solar UV exposure in adulthood was modestly associated with later onset of menopause. Although consistent with previous findings on vitamin D intake and menopause in the same population, these weak associations found in this study may not be of clinical relevance.

The significant role of dietary intake of vitamin D in non-menopausal women health

Optimal vitamin D status is very important for reflecting not only bone but overall woman's health. The aim of the study was to determine pharmacokinetic variability of 25-hydroxy vitamin D, to reveal and quantify the most significant factors that affect its variability in the population of healthy non-menopausal women using the population pharmacokinetic (PopPK) approach. The study population consisted of 74 healthy reproductive women aged from 35 to 50 years, without the use of any supplement. A population pharmacokinetics analysis was conducted using a nonlinear mixed-effects model software. A total of 35 factors were assessed: demographic, clinical, biochemical data and lifestyle factors. The average age and bodyweight of our participants were 40.11 ± 4.35 years 65.30 ± 6.80 kg, respectively. The observed mean serum concentration of 25-hydroxy vitamin D was 26.51 ± 13.49 ng/mL with a wide range of 6.97 to 59.89 ng/mL. Development final PopPK model of the clearance of 25-hydroxy vitamin D showed that only the average daily dose of vitamin D intake from food had a significant influence, with a magnitude of its effects of 0.00401. These results could help when individualizing vitamin D intake in the form of supplements, especially during the wintertime, in healthy reproductive women.

Vitamin D and Reproductive Hormones Across the Menstrual Cycle

STUDY QUESTION

How do the calciotropic hormones (25-hydroxyvitamin D, 1,25-dihydroxyvitamin D and intact parathyroid hormone (iPTH)) vary across the menstrual cycle and do cyclic patterns of reproductive hormones (estradiol, progesterone, LH, FSH) differ by vitamin D status?

SUMMARY ANSWER

Calciotropic hormones vary minimally across the menstrual cycle; however, women with 25-hydroxyvitamin D below 30 ng/ml have lower mean estradiol across the menstrual cycle.

WHAT IS KNOWN ALREADY

Prior human studies suggest that vitamin D status is associated with fecundability, but the mechanism is unknown. Exogenous estrogens and prolonged changes in endogenous estradiol (pregnancy or menopause) influence concentrations of 25-hydroxyvitamin D. In vitro, treatment with 1,25-dihydroxyvitamin D increases steroidogenesis in ovarian granulosa cells. There are little data about changes in calciotropic hormones across the menstrual cycle or cyclic patterns of reproductive hormones by categories of vitamin D status.

STUDY DESIGN, SIZE, DURATION

A prospective cohort study of 89 self-identified white women aged 18-44, across two menstrual cycles. Participants were a subset of the BioCycle Study, a community-based study conducted at the University of Buffalo, 2005-2007.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Eligible participants had self-reported regular menstrual cycles between 21 and 35 days and were not using hormonal contraception or vitamins. Early morning fasting blood samples were drawn at up to eight study visits per cycle. Visits were timed to capture information in all cycle phases. Serum samples for 89 women (N = 163 menstrual cycles) were analyzed for estradiol, progesterone, LH, FSH and 25-hydroxyvitamin D (25(OH)D). Variability in calciotropic hormones within and across menstrual cycles was assessed using intraclass correlation coefficients and non-linear mixed models. Given the relative stability of the calciotropic hormones across the menstrual cycle, non-linear mixed models were used to examine differences in the cyclic patterns of estradiol, progesterone, LH and FSH by categories of each calciotropic hormone (split at the median). These models were conducted for all ovulatory cycles (N = 142 ovulatory menstrual cycles) and were adjusted for age, BMI (measured in clinic) and self-reported physical activity.

MAIN RESULTS AND THE ROLE OF CHANCE

Median 25(OH)D concentration was 29.5 ng/ml (SD 8.4), and only 6% of women had vitamin D deficiency (<20 ng/ml). The mean concentration of 25(OH)D did not differ between the luteal and follicular phase; however, both 1,25(OH)2D and iPTH showed small fluctuations across the menstrual cycle with the highest 1,25(OH)2D (and lowest iPTH) in the luteal phase. Compared with women who had mean 25(OH)D ≥30 ng/ml, women with lower 25(OH)D had 13.8% lower mean estradiol (95% confidence interval: -22.0, -4.7) and 10.8% lower free estradiol (95% CI: -0.07, -0.004). Additionally, compared to women with iPTH ≤36 pg/ml, women with higher concentrations of iPTH had 12.7% lower mean estradiol (95% CI: -18.7, -6.3) and 7.3% lower progesterone (95% CI: -13.3, -0.9). No differences in the cyclic pattern of any of the reproductive hormones were observed comparing cycles with higher and lower 1,25(OH)2D.

LIMITATIONS, REASONS FOR CAUTION

Women included in this study had self-reported 'regular' menstrual cycles and very few were found to have 25(OH)D deficiency. This limits our ability to examine cycle characteristics, anovulation and the effects of concentrations of the calciotropic hormones found in deficient individuals. Additionally, the results may not be generalizable to women with irregular cycles, other races, or populations with a higher prevalence of vitamin D deficiency.

WIDER IMPLICATIONS OF THE FINDINGS

These findings support current clinical practice that does not time testing for vitamin D deficiency to the menstrual cycle phase. We find that women with lower vitamin D status (lower 25(OH)D or higher iPTH) have lower mean concentrations of estradiol across the menstrual cycle. Although this study cannot identify a mechanism of action, further in vitro work or clinical trials may help elucidate the biologic mechanisms linking calciotropic and reproductive hormones.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the Intramural Research Programs of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (contract numbers: HHSN275200403394C, HHSN275201100002I and Task 1 HHSN27500001) and the National Institute of Environmental Health Sciences. There are no competing interests.

Morphological changes in the experimental model of polycystic ovary syndrome and effects of vitamin D treatment

AIM

This research was designed to develop an animal model by inducing polycystic ovary syndrome (PCOS) with dehydroepiandrosterone (DHEA) and observe reproductive and morphological changes after treatment with vitamin D.

MATERIALS AND METHODS

Thirty pre-pubertal female Sprague-Dawley (SD) dams were recruited. The animals were distributed 10 each in control, PCOS and vitamin D-treated groups. In control group 0.2 ml of sesame oil was given. PCOS group was administered DHEA by the daily dose of 6 mg/kg for 30 days. In vitamin D-treated group, animals were injected 6 mg/kg/day DHEA daily and 120 ng 1, 25(OH) 2D3/100 g subcutaneously once a week. The occurrence of reproductive phenotypic PCOS was evaluated by estrous cycle, morphology and histological changes of ovary, uterus on light microscope.

RESULTS

The results of this study showed significant weight gain, obesity, and estrous irregularity in PCOs group as compared to control and vitamin D-treated group.

CONCLUSION

Administration of vitamin D (120 ng 1, 25(OH) 2D3/100) improved the cycle characteristics, reduced body weight and morphological features in PCOS induced animals. The results support the effect of vitamin D treatment for metabolic and reproductive characteristic features in PCOS females.

Development and Effects of College-Based Lifestyle Modification Program for Menstrual Health of Young Adult Women with Irregular Menses: A Randomized Controlled Trial

Purpose: This study was conducted to develop the 'College-based Lifestyle Modification Program' (College-based LMP) for young adult women with irregular menstruation and examine its effects after intervention. Methods: The College-based LMP consisted of small group education, individual physical exercise counseling/training, individual diet counseling, and feedback and support. Participants were comprised of 38 females who reported less than 10 irregular menstruations in a year and were randomly assigned to the experimental and control groups. The primary outcome variables consisted of menstrual cycle index (MCI), sex hormone binding globulin (SHBG), and androgenic profile (testosterone-T, free androgen index-FAI), while the outcome variables included premenstrual symptoms (PMS), menstrual volume, body composition parameters, glycemic parameters (fasting blood sugar-FBS, insulin, HOMA-IR), sleep duration, perceived stress, and nutrient intake.. Results: There were no significant differences in primary outcome variables (MCI, SHBG, T, and FAI). In the variables, there were no significant differences except for the partial domain of PMS (symptoms of depression and anxiety) and sleep duration. Conclusions: The study was significant in that it demonstrated the importance of lifestyle, which could provide ordinary young adult women with healthy menstruation. The College-based LMP needs to be elaborated with further studies.

Towards a comprehensive etiopathogenetic and pathophysiological theory of multiple sclerosis

Background: Multiple sclerosis (MS) is a neurodegenerative disease caused by dysfunction of the immune system that affects the central nervous system (CNS). It is characterized by demyelination, chronic inflammation, neuronal and oligodendrocyte loss and reactive astrogliosis. It can result in physical disability and acute neurological and cognitive problems. Despite the gains in knowledge of immunology, cell biology, and genetics in the last five decades, the ultimate etiology or specific elements that trigger MS remain unknown. The objective of this review is to propose a theoretical basis for MS etiopathogenesis.Methods: Search was done by accessing PubMed/Medline, EBSCO, and PsycINFO databases. The search string used was "(multiple sclerosis* OR EAE) AND (pathophysiology* OR etiopathogenesis)". The electronic databases were searched for titles or abstracts containing these terms in all published articles between January 1, 1960, and June 30, 2019. The search was filtered down to 362 articles which were included in this review.Results: A framework to better understand the etiopathogenesis and pathophysiology of MS can be derived from four essential factors; mitochondria dysfunction (MtD) & oxidative stress (OS), vitamin D (VD), sex hormones and thyroid hormones. These factors play a direct role in MS etiopathogenesis and have a modulatory effect on many other factors involved in the disease.Conclusions: For better MS prevention and treatment outcomes, efforts should be geared towards treating thyroid problems, sex hormone alterations, VD deficiency, sleep problems and melatonin alterations. MS patients should be encouraged to engage in activities that boost total antioxidant capacity (TAC) including diet and regular exercise and discouraged from activities that promote OS including smoking and alcohol consumption.

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.

25-Hydroxyvitamin D (25(OH)D) and biomarkers of ovarian reserve

OBJECTIVE

The aim of the study was to examine the associations between 25-hydroxyvitamin D (25(OH)D) and biomarkers of ovarian reserve in a large community-based sample of women.

METHODS

In 2010 to 2016, women aged 30 to 44 years without any known fertility problems were recruited from the Chapel Hill, NC area for a prospective time-to-pregnancy cohort study. At enrollment 561 women provided a blood sample that was used to measure 25(OH)D, anti-Müllerian hormone (AMH), follicle-stimulating hormone, and inhibin-B. Unadjusted associations were estimated with Spearman correlation coefficients. Multivariable linear regression was used to estimate associations of 25(OH)D with ovarian reserve biomarkers, after adjusting for age, race, body mass index, smoking history, and recent use of hormonal birth control.

RESULTS

The mean 25(OH)D was 36 ng/mL (SD = 11 ng/mL). 25(OH)D was not correlated with AMH, follicle-stimulating hormone, or inhibin-B (all r < 0.03). Multivariable results with continuous hormonal outcomes were also null. For dichotomous outcomes, there was a tendency for insufficient 25(OH)D (<30 ng/mL) to be associated with low AMH (<0.7 ng/mL) (odds ratio [95% CI]: 1.8 [0.9-4]).

CONCLUSIONS

For the most part, 25(OH)D was not associated with ovarian reserve biomarkers in a group of women trying to become pregnant. We found some evidence that low 25(OH)D (<30 ng/mL) was associated with low AMH, but this should be confirmed in studies with a higher prevalence of low 25(OH)D.

Vitamin D metabolites across the menstrual cycle: a systematic review

Background

Accurate estimation of vitamin D status is important for health research and can impact prevention and treatment of deficiency in women of reproductive age. We aimed to assess if blood concentrations of 25-hydroxyvitamin D [25(OH)D] or 1,25-dihydroxyvitamin D [1,25(OH)₂D] change across the menstrual cycle.

Methods

We conducted a systematic search in PubMed, Web of Science, CAB and BIOSIS of literature published until December 2018 which reported concentrations of vitamin D metabolites at two or more identified points among women with regular menstrual cycles.

Results

Ten longitudinal studies met the inclusion criteria; nine studies measured 1,25(OH)₂D and five studies measured 25(OH)D. Study size ranged from 5 to 47 subjects, with an age range of 18–47 years. One study found a decrease in concentration of 25(OH)D in the periovulatory and luteal phase. Four studies found no changes in concentrations of 25(OH)D. Two studies found a rise in 1,25(OH)₂D within the follicular phase, including a 128% increase from day 1 to 15 and a 56% increase from day 0 to 12. Two studies found rises in 1,25(OH)₂D concentrations from the follicular to luteal phase of 13 and 26%. Five studies did not find any changes in concentrations of 1,25(OH)₂D.

Conclusions

No conclusion can be drawn on the pattern of 1,25(OH)₂D concentrations across the normal menstrual cycle due to inconsistencies in study findings. Evidence is currently insufficient to assess 25(OH)D concentrations across the cycle. Future studies should aim to measure 1,25(OH)₂D and 25(OH)D longitudinally, to understand relationships with other hormones and the potential impact on estimates of vitamin D deficiency.

The Relationship between Vitamin D Status and the Menstrual Cycle in Young Women: A Preliminary Study

Background: The aim of this study was to evaluate serum vitamin D levels and to compare these with the menstrual cycle in young women with different body weights. Methods: Eighty-four students were recruited into the study of which 77 remained at the study’s completion. Women were assigned to one of two subgroups, according to their 25-hydroxy vitamin D test level [25(OH)D] in which 60 women had low 25(OH)D levels (LD < 30 ng/mL) and 17 had normal levels (ND > 30 ng/mL ≤ 80 ng/mL). Results: In the LD group, 40% of participants reported having long cycles, 27% were classified as having oligomenorrhoea, and 13% as having amenorrhoea. In the ND group, only 12% reported menstrual cycle disorders, 6% had oligomenorrhoea, and 6% had amenorrhoea. Women who did not meet the recommended level of 30 ng/mL of 25(OH)D had almost five times the odds of having menstrual cycle disorders as women who were above the recommended vitamin D level. Conclusion: A relationship was demonstrated between the frequency of menstrual disorders and low levels of vitamin D. Supplementation is necessary in women with low levels of vitamin D in order to compensate for this deficiency and to assess its effect in regulating menstrual disorders.

High dose vitamin D supplementation can improve menstrual problems, dysmenorrhea, and premenstrual syndrome in adolescents

Vitamin D has a crucial role in female reproduction, possibly through its effects on calcium homeostasis, cyclic sex steroid hormone fluctuations, or neurotransmitter function. We have assessed the effects of vitamin D supplementation on dysmenorrhea and premenstrual syndrome (PMS) in adolescents. In this study, 897 adolescent girls living in Mashhad and Sabzevar, Iran, received nine high-dose vitamin D supplements (as 50,000 IU/week of cholecalciferol) and were followed up over 9 weeks. We evaluated the effect of vitamin D supplementation on individuals in four categories: those with only PMS; individuals with only dysmenorrhea; subjects with both PMS and dysmenorrhea and normal subjects. The prevalence of PMS after the intervention fell from 14.9% to 4.8% (p < .001). Similar results were also found for the prevalence of subjects with dysmenorrhea (35.9% reduced to 32.4%), and in subjects with both PMS and dysmenorrhea (32.7% reduced 25.7%). Vitamin D supplementation was associated with a reduction in the incidence of several symptoms of PMS such as backache and tendency to cry easily as well as decrement in pain severity of dysmenorrhea (p < .05). High dose vitamin D supplementation can reduce the prevalence of PMS and dysmenorrhea as well as has positive effects on the physical and psychological symptoms of PMS.

Vitamin D and Uterine Fibroids-Review of the Literature and Novel Concepts

This article provides a detailed review of current knowledge on the role of vitamin D and its receptor in the biology and management of uterine fibroids (UFs). Authors present ideas for future steps in this area. A literature search was conducted in PubMed using the following key words: "uterine fibroid" and "vitamin D". The results of the available studies, published in English from January 2002 up to April 2018, have been discussed. Vitamin D is a group of steroid compounds with a powerful impact on many parts of the human body. This vitamin is believed to regulate cell proliferation and differentiation, inhibit angiogenesis, and stimulate apoptosis. Nowadays, hypovitaminosis D is believed to be a major risk factor in the development of UFs. In many studies vitamin D appears to be a powerful factor against UFs, resulting in inhibition of tumor cell division and a significant reduction in its size, however, the exact role of this compound and its receptor in the pathophysiology of UFs is not fully understood. According to available studies, vitamin D and its analogs seem to be promising, effective, and low-cost compounds in the management of UFs and their clinical symptoms, and the anti-tumor activities of vitamin D play an important role in UF biology. The synergy between vitamin D and selected anti-UF drugs is a very interesting issue which requires further research. Further studies about the biological effect of vitamin D on UF biology are essential. Vitamin D preparations (alone or as a co-drugs) could become new tools in the fight with UFs, with the additional beneficial pleiotropic effect.

Evaluating the effects of administration of 25-hydroxyvitamin D supplement on serum anti-mullerian hormone (AMH) levels in infertile women

The aim of the study was to evaluate the effects of administration of 25-hydroxyvitamin D [25(OH) D] on serum antimullerian hormone (AMH) levels in infertile women. The study was performed as a non-randomized clinical trial on 30 infertile women who had low serum level of both 25(OH) D and anti-mullerian hormone. Vitamin D was prescribed 50,000 IU weekly for up to three months for all eligible participants. Serum levels of both 25(OH) D and AMH have increased significantly after treatment with 25(OH) D. There was a significant correlation between serum levels of 25(OH) D after treatment with AMH (p = .029, OR = 2.9, CI 95% = 2.7-5.5). Mean AMH level after treatment was higher in women with sufficient 25(OH) D, than women with insufficient 25(OH) D (1.048 ± 0.644 vs. 0.513 ± 0.284 ng/ml), which shows a significant difference (p = .043). Also, after treatment, in women with mean AMH level of >0.7 ng/ml (19 women), mean level of 25(OH) D was higher than in women with mean AMH level of <0.7 ng/ml (11 women) (59.332 ± 21.751 vs. 38.881 ± 17.281 ng/ml, p = .013). This means that higher levels of 25(OH) D are accompanied with higher levels of AMH. In conclusions with administration and increasing the amount of vitamin D serum levels, the serum levels of AMH have increased.

25-Hydroxyvitamin D and Long Menstrual Cycles in a Prospective Cohort Study

BACKGROUND

Vitamin D insufficiency is associated with subfertility and prolonged estrus cycles in animals, but humans have not been well studied.

METHODS

A prospective time-to-pregnancy study, Time to Conceive (2010-2015), collected up to 4 months of daily diary data. Participants were healthy, late reproductive-aged women in North Carolina who were attempting pregnancy. We examined menstrual cycle length as a continuous variable and in categories: long (35+ days) and short (≤25 days). Follicular phase length and luteal phase length were categorized as long (18+ days) or short (≤10 days). We estimated associations between those lengths and serum 25-hydroxyvitamin D (25[OH]D) using linear mixed models and marginal models.

RESULTS

There were 1,278 menstrual cycles from 446 women of whom 5% were vitamin D deficient (25[OH]D, <20 ng/ml), 69% were between 20 and 39 ng/ml, and 26% were 40 ng/ml or higher. There was a dose-response association between vitamin D levels and cycle length. Compared with the highest 25(OH)D level (≥40 ng/ml), 25(OH)D deficiency was associated with almost three times the odds of long cycles (adjusted odds ratio [aOR] = 2.8 [95% confidence interval (CI) = 1.0, 7.5]). The aOR was 1.9 (1.1, 3.5) for 20 to <30 ng/ml. The probability of a long follicular phase and the probability of a short luteal phase both increased with decreasing 25(OH)D.

CONCLUSIONS

Lower levels of 25(OH)D are associated with longer follicular phase and an overall longer menstrual cycle. Our results are consistent with other evidence supporting vitamin D's role in the reproductive axis, which may have broader implications for reproductive success.

Increasing serum 25-hydroxyvitamin D is associated with reduced odds of long menstrual cycles in a cross-sectional study of African American women

OBJECTIVE

To examine the association between serum 25-hydroxyvitamin D [25(OH)D] and menstrual cycle length and regularity.

DESIGN

Community-based, cross-sectional study of serum 25(OH)D (adjusted for seasonal differences in timing of blood draw) and menstrual cycle length. Women aged 23-34 years reported their gynecologic history. Menstrual cycles were described with four independent categories (normal, short, long, irregular). We used polytomous logistic regression to estimate the association between a doubling of seasonally adjusted 25(OH)D and the odds of each cycle category.

SETTING

Not applicable.

PATIENT(S)

A total of 1,102 African American women.

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

Self-reported menstrual cycle length over the previous 12 months, excluding women who were using cycle-regulating medications over the entire year. Women who reported that their cycles were "too irregular to estimate" were classified as having irregular cycles. A typical cycle length of <27 days was considered "short," >34 days was "long," and 27-34 days was "normal."

RESULT(S)

The median 25(OH)D level was 14.7 ng/mL (interquartile range, 10.9-19.6 ng/mL). A doubling of 25(OH)D was associated with half the odds of having long menstrual cycles: adjusted odds ratio (aOR) 0.54, 95% confidence interval (CI) 0.32-0.89. 25-Hydroxyvitamin D was not associated with the occurrence of short (aOR 1.03, 95% CI 0.82-1.29) or irregular (aOR 1.46, 95% CI 0.88-2.41) menstrual cycles. Results were robust to several sensitivity analyses.

CONCLUSION(S)

These findings suggest that vitamin D status may influence the menstrual cycle and play a role in ovarian function. Further investigation of 25(OH)D and ovarian hormones, and prospective studies of 25(OH)D and cycle length, are needed.