Association between Vitamin D Status and Premenstrual Symptoms

Effect of nutritional interventions on the psychological symptoms of premenstrual syndrome in women of reproductive age: a systematic review of randomized controlled trials

CONTEXT

Premenstrual syndrome (PMS) affects approximately 48% of women of reproductive age worldwide. It can lead to functional impairment, lower quality of life, and decreased work productivity. Despite the availability of medical treatment options, women are seeking alternative interventions because of concerns of harmful side effects and limited evidence of efficacy associated with pharmacological treatments. To date, high-quality research investigating the effects of dietary and nutrient intervention on PMS is limited.

OBJECTIVE

This systematic review investigated the effect of nutritional interventions on the psychological symptoms of PMS.

DATA SOURCES

Five electronic databases were searched for randomized controlled trials (RCTs) published in English from inception to October 2022. Trials eligible for inclusion were nutritional intervention studies involving women of reproductive age that measured PMS-associated psychological outcomes.

DATA EXTRACTION

Articles were selected using prespecified inclusion criteria. Data screening and extraction and risk-of-bias assessments were conducted by 3 independent reviewers using article screening software and the Cochrane Risk of Bias 2 tool.

DATA ANALYSIS

Thirty-two articles reporting on 31 RCTs involving 3254 participants, ranging in age from 15 to 50 years were included and narratively reviewed. Only 1 of the included studies had a low risk of bias. Treatment with vitamin B6, calcium, and zinc consistently had significant positive effects on the psychological symptoms of PMS. There was insufficient evidence to support the effects of vitamin B1, vitamin D, whole-grain carbohydrates, soy isoflavones, dietary fatty acids, magnesium, multivitamin supplementation, or PMS-specific diets.

CONCLUSIONS

There is some evidence to support the use of nutritional interventions for improving psychological symptoms of PMS. However, more research using consistent protocols, procedures to minimize risk of bias, intention-to-treat analysis, and clearer reporting is required to provide conclusive nutritional recommendations for improving PMS-related psychological outcomes.

PROSPERO REGISTRATION NO

CRD42022369999.

The link between childhood traumatic events and the continuum of premenstrual disorders

Background

Premenstrual Syndrome (PMS) and Premenstrual Dysphoric Disorder (PMDD), collectively known as Premenstrual Disorders (PMDs), cause significant distress and functional impairment, and premenstrual exacerbation (PME) affects a large proportion of women with psychiatric diagnoses. Childhood trauma is one factor that may contribute to PMD/PME risk. This study examines the relationship between childhood trauma and PMDs, PME, and non-PMD psychiatric illness.

Methods

This study is a secondary analysis of data from a prospective cohort. Participants completed self-assessments on childhood trauma using the Childhood Traumatic Event Scale (CTE-S) and on premenstrual symptoms using the Premenstrual Symptoms Screening Tool (PSST). Psychiatric diagnoses were assessed through structured clinical interviews. Participants were divided into four groups based on their PSST scores and psychiatric illness status: (1) Premenstrual Disorders (PMDs; moderate to severe PMS and PMDD), (2) PME, (3) psychiatric controls (PC; individuals with psychiatric illness but no significant premenstrual symptoms), and (4) healthy controls (HC; individuals with no psychiatric illness and no significant premenstrual symptoms). Statistical analyses, including ANOVA, Tukey's HSD test, Fisher's exact test, and logistic regression, were conducted to examine differences among the groups.

Results

Data from 391 participants were analyzed. Participants with PME and PC reported a higher quantity and severity of childhood traumatic events compared to HCs (p <.05). There was a weak but significant correlation between childhood trauma and premenstrual symptom burden across all groups (R = .18, p <.001). Within-group analysis revealed moderate correlations between childhood trauma and premenstrual symptoms driven by the PMD group (R = .42, p = .01).

Conclusions

The findings underscore the impact of childhood traumatic events on mental health and premenstrual symptoms and highlight the need for additional research to explore the underlying mechanisms linking childhood trauma to the continuum of premenstrual disorders, to improve the efficacy of trauma-focused interventions for affected individuals.

Effect of vitamin D supplementation on symptoms severity in vitamin D insufficient women with premenstrual syndrome: A randomized controlled trial

BACKGROUND

Premenstrual syndrome (PMS) is one of the most prevalent disorders among reproductive women worldwide that negatively impact women's quality of life. This study aimed to investigate the effect of vitamin D supplementation on the severity of PMS symptoms in vitamin D insufficient women with PMS.

METHODS

In this randomized, double-blind clinical trial, 44 vitamin D insufficient women with PMS received either 50,000 IU vitamin D or a placebo fortnightly for 16 weeks. Participants completed the PMS Daily Symptoms Rating form at beginning and during the last two months of the intervention, and their blood samples were collected to assess 25(OH)D serum levels.

RESULTS

After the four months' intervention, the serum level of 25(OH)D in the vitamin D group raised from 21 ± 8 ng/ml to 40 ± 8 ng/ml (P < 0.001), while in the placebo group it raised from 21 ± 7 ng/ml to 23 ± 7 ng/ml (P = 0.03). Indeed, serum vitamin D levels in the placebo group could not reach a sufficient level. At the end of the intervention, the mean score of total PMS symptoms showed significant improvement in the vitamin supplemented group compared to the controls (p < 0.001). By grouping the PMS symptoms into five subgroups, the mean score of all five subgroups decreased post-supplementation compared to the baseline; however, the highest and lowest decrease were in depression (53 %) and water retention subgroups (28 %), respectively. This indicates a greater improvement in the mean scores of mood symptoms compared to physical symptoms in this study (p < 0.001).

CONCLUSION

Results obtained in this clinical trial represent the helpful effects of vitamin D supplementation on total, physical and mood symptoms in vitamin D insufficient women with PMS.

TRIAL REGISTRATION

This randomized controlled trial at IRCT.ir on 2018-06-20 with Registration No: IRCT20180525039822N1.

Online positive-oriented counseling, taking vitamin D3 tablet, online lifestyle modification training on premenstrual syndrome: a 3-armed randomized clinical trial

Lack of absolute treatment for premenstrual syndrome (PMS), its cyclic nature, considerable prevalence (70-90%), and its mental and physical burden imply necessity of effectiveness comparison of various treatments. Although antidepressant and hormonal drugs are well-known medications for PMS, in affected women who can't tolerate, or don't have compatibility or compliance with these drugs, other effective treatments have always been important concern. This study aimed to compare effectiveness of online positive-oriented counseling, taking vitamin D3 tablet, and online lifestyle modification training on alleviating PMS. 3-armed parallel randomized clinical trial was performed on 84 20-40-year-old eligible women with PMS. 84 women were randomly ( www.random.org/sequenc ) allocated into three groups, but data of 77 women (1, n = 25) online positive-oriented counseling group (6 sessions), (2, n = 27) vitamin D3 tablet group (one vitamin D3 tablet weekly for 6 weeks), and (3, n = 25) online lifestyle training group (6 sessions) were analyzed. Vitamin D3 was measured at baseline, week6 and fallow up week10. Primary outcome variable PMS was measured with Premenstrual Symptoms Screening Tool (PSST) at baseline, week 6, and follow-up week 10. Primary outcome satisfaction with intervention method was measured using satisfaction scale at week 6 and follow-up week 10. ANOVA, Repeated Measures, and Paired samples t-test were used for statistical analysis. There was no statistically significant difference in PMS at baseline between three groups respectively (33 ± 5.8, 34.1 ± 7.1, & 35.2 ± 6.4, P = 0.500). However, at follow-up week 10, there was statistically significant difference between three groups (22.3 ± 4.3, 25.4 ± 6.5, & 31.8 ± 6.5; P < 0.001), with greatest improvement in online positive-oriented counseling group (P < 0.001). Satisfaction differed significantly among three groups at week 6 (51 ± 6.8, 46.4 ± 12, & 42.3 ± 6.3, P = 0.001) and follow-up week 10 (55.7 ± 11.6, 51.4 ± 12; & 43 ± 3.3, P < 0.001), with most satisfaction in positive-oriented counseling group (P < 0.001). All three interventions alleviated PMS, but online positive-oriented counseling was more effective and satisfying. Superiority of positive-oriented counseling implies mechanism of adaptation, better relationships, forgiveness, self-mood-regulation, and feasibility of its skills that could be continued individually by women after counseling completion. It is recommended health providers, health policymakers and managers support use of these interventions in treatment program and clinical guidelines.Trial registration: RCT registration number: IRCT20191231045967N1, Registration date:11/02/2020, Registration timing: prospective (IRCT | Survey the effect of vitamin D3 tablet intake, positivism group consulting with changing in life style in the treatment of premenstrual syndrome in women).

Fasting plasma glucose and serum 25-hydroxy vitamin D levels in individuals with Middle Eastern and Swedish descent

Purpose

To determine fasting plasma glucose and serum 25-hydroxyvitamin D (s-25(OH)D) levels and associations between abnormal fasting plasma glucose levels and inadequate s-25(OH)D levels in individuals of Middle Eastern and Swedish descent.

Methods

Observational study with individuals without a diabetes diagnosis, 54.5% of Swedish descent and 45.5% of Middle Eastern descent. In total, 830 participants from two primary healthcare centres in Flemingsberg and Jakobsberg, which are southern and northern suburbs, respectively, of Stockholm, Sweden were included in the study.

Results

Prevalence of inadequate s-25(OH)D levels (at or below 50 nmol/L) was 67.2% among those of Middle Eastern descent and 20.5% among those of Swedish descent (P < 0.001). S-25(OH)D levels correlated weakly positively with fasting plasma glucose levels (ρ = 0.20, P = 0.002) in individuals of Middle Eastern descent. Being of Middle Eastern descent (OR 6.7, 95% CI 4.3-10.4) and having abnormal fasting plasma glucose (OR 1.8, 95% CI 1.2-2.9) were independent predictors of having inadequate s-25(OH)D levels.

Conclusions

Healthcare in Sweden should consider testing fasting plasma glucose and s-25(OH)D levels, particularly in individuals of Middle Eastern descent. The unclear relationship between vitamin D and glucose levels warrants investigation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-023-01226-0.

Associations Between Dietary Vitamin C, Serum Ascorbic Acid, and GSTT1 Genotype and Premenstrual Symptoms

OBJECTIVE

Premenstrual symptoms are a cyclically occurring combination of adverse psychological and somatic symptoms that impact the quality of life for most females of childbearing age. Growing evidence suggests that diet may attenuate premenstrual symptoms; however, the relationship between vitamin C and premenstrual symptoms remains unclear. The aim of the research was to determine the association between different measures of vitamin C status and premenstrual symptoms.

METHOD

Females (n = 555) aged 20 to 29 years from the Toronto Nutrigenomics and Health Study completed a General Health and Lifestyle Questionnaire, capturing 15 premenstrual symptoms. Dietary intake was measured using a 196-item Toronto-modified Harvard food frequency questionnaire. Serum ascorbic acid concentrations were measured, and participants were categorized into deficient (<11 µmol/L), suboptimal (11-28 µmol/L), and adequate (>28 µmol/L) ascorbic acid levels. DNA was genotyped for the GSTT1 (Ins/Del) polymorphism. Using logistic regression, odds of experiencing premenstrual symptoms were compared between vitamin C intake levels above and below the recommended daily allowance (75 mg/d) between ascorbic acid levels and between GSTT1 genotypes.

RESULTS

Increased vitamin C intake was associated with premenstrual appetite changes (OR, 1.65; 95% CI, 1.01-2.68). Compared to deficient ascorbic acid levels, suboptimal levels were associated with premenstrual appetite changes (OR, 2.59; 95% CI, 1.02-6.58) and bloating/swelling (OR, 3.00; 95% CI, 1.09-8.22). Adequate serum ascorbic acid levels were not associated with premenstrual appetite changes (OR, 1.69; 95% CI, 0.73-3.94) or bloating/swelling (OR, 1.92; 95% CI, 0.79-4.67). Those with the GSTT1 functional variant (Ins*Ins) had an increased risk of premenstrual bloating/swelling (OR, 1.96; 95% CI, 1.10-3.48); however, the interaction between vitamin C intake and GSTT1 was not significant for any premenstrual symptoms.

CONCLUSIONS

Our findings suggest that indicators of higher vitamin C status are associated with increased premenstrual appetite changes and bloating/swelling. The observed associations with GSTT1 genotype suggest that these observations are not likely due to reverse causation.

Factors Associated with the Prevalence and Severity of Menstrual-Related Symptoms: A Systematic Review and Meta-Analysis

This study aimed to identify factors associated with the prevalence and severity of menstrual-related symptoms. The protocol was registered in PROSPERO (CRD42021208432). We conducted literature searches of PubMed and Ichushi-Web and used the Jonna Briggs Institute critical appraisal checklist to assess the quality. Of the 77 studies included in the meta-analysis, significant odds ratios (ORs) were obtained for eight factors associated with primary dysmenorrhea (PD): age ≥ 20 years (OR: 1.18; 95% confidence interval [CI]: 1.04−1.34), body mass index (BMI) < 18.5 kg/m2 (OR: 1.51; 95% CI: 1.01−2.26), longer menstrual periods (OR: 0.16; 95% CI: 0.04−0.28), irregular menstrual cycle (OR: 1.28; 95% CI: 1.13−1.45), family history of PD (OR: 3.80; 95% CI: 2.18−6.61), stress (OR: 1.88; 95% CI: 1.30−2.72), sleeping hours < 7 h (OR: 1.19; 95% CI: 1.04−1.35), and bedtime after 23:01 (OR: 1.30; 95% CI: 1.16−1.45). Two factors were associated with severity of PD (moderate vs. severe): BMI < 18.5 kg/m2 (OR: 1.89; 95% CI: 1.01−3.54) and smoking (OR: 1.94; 95% CI: 1.08−3.47). PD severity (mild vs. severe) and prevalence of premenstrual syndrome were associated with BMI < 18.5 kg/m2 (OR: 1.91; 95% CI: 1.04−3.50) and smoking (OR: 1.86; 95% CI: 1.31−2.66), respectively. The identified risk factors could be utilized to construct an appropriate strategy to improve menstrual symptoms and support women’s health.

Environmental risk factors, protective factors, and biomarkers for postpartum depressive symptoms: an umbrella review

We performed an umbrella review on environmental risk/protective factors and biomarkers for postpartum depressive symptoms to establish a hierarchy of evidence. We systematically searched PubMed, Embase, and the Cochrane Database of Systematic Reviews from inception until 12 January 2021. We included systematic reviews providing meta-analyses related to our research objectives. Methodological quality was assessed by AMSTAR 2, and the certainty of evidence was evaluated by GRADE. This review was registered in PROSPERO (CRD42021230784). We identified 30 articles, which included 45 environmental risk/protective factors (154,594 cases, 7,302,273 population) and 9 biomarkers (2018 cases, 16,757 population). The credibility of evidence was convincing (class I) for antenatal anxiety (OR 2.49, 1.91-3.25) and psychological violence (OR 1.93, 1.54-2.42); and highly suggestive (class II) for intimate partner violence experience (OR 2.86, 2.12-3.87), intimate partner violence during pregnancy (RR 2.81, 2.11-3.74), smoking during pregnancy (OR 2.39, 1.78-3.2), history of premenstrual syndrome (OR 2.2, 1.81-2.68), any type of violence experience (OR 2.04, 1.72-2.41), primiparity compared to multiparity (RR 1.76, 1.59-1.96), and unintended pregnancy (OR 1.53, 1.35-1.75).

Variation in the vitamin D receptor gene, plasma 25-hydroxyvitamin D, and risk of premenstrual symptoms

Background

Vitamin D status has been associated with the presence and severity of several premenstrual symptoms (PMSx) in some, but not all studies. Inconsistencies among findings may be explained by unaccounted genetic variation in the vitamin D receptor (VDR).

Objective

To determine whether associations between vitamin D status and individual PMSx are influenced by VDR genotype.

Methods

Seven hundred sixteen women aged 20-29 years old from the Toronto Nutrigenomics and Health study provided plasma samples and completed a questionnaire on the presence and severity of 15 common PMSx. Plasma 25-hydroxyvitamin D (25(OH)D) concentration was measured and participants were categorized into sufficient (≥ 50 nmol/L) and insufficient (< 50 nmol/L) vitamin D status groups. DNA was obtained from blood samples to genotype for a common VDR single nucleotide variant, rs796858. Using logistic regression, odds of experiencing PMSx were compared between vitamin D-sufficient and insufficient women, stratified by genotype.

Results

Among CC homozygotes, insufficient vitamin D status was associated with higher odds of experiencing premenstrual fatigue (OR, 2.53; 95% CI, 1.40, 4.56) and nausea (OR, 2.44; 95% CI, 1.00, 5.95). Among TT homozygotes, insufficient vitamin D status was associated with lower odds of experiencing fatigue (OR, 0.44; 95% CI, 0.20, 0.97) and increased appetite (OR, 0.48; 95% CI, 0.22, 1.04). Insufficient vitamin D status was associated with higher odds of increased appetite in women with the CT genotype (OR, 1.78; 95% CI, 1.03, 3.07). VDR genotype modified the association between vitamin D status and the following PMSx: increased appetite (interaction p = 0.027), fatigue (interaction p = 0.016), and nausea (interaction p = 0.039).

Conclusion

We found evidence that VDR genotype may modify the association between 25(OH)D and some PMSx. Insufficient 25(OH)D was associated with a higher risk of premenstrual fatigue in those with the CC genotype, but lower risk in those with the TT genotype.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12263-021-00696-2.

Plasma Carotenoids and Premenstrual Symptoms in a Multi-Ethnic Population of Young Women

Premenstrual symptoms are experienced by most women of reproductive age, but effective therapies are limited. Carotenoids may have an attenuating effect on premenstrual symptoms; however, studies to date are equivocal. The objective of the present study was to examine the association between plasma concentrations of seven carotenoids and premenstrual symptom severity in 553 women from the Toronto Nutrigenomics and Health study. Participants provided information on fifteen common premenstrual symptoms and severities. Each participant completed a General Health and Lifestyle Questionnaire and provided a fasting blood sample from which plasma carotenoid concentrations were measured. Multinomial logistic regressions were used to determine associations between plasma carotenoid concentrations and premenstrual symptom severity. Beta-cryptoxanthin was associated with moderate/severe increased appetite for women in the highest compared to the lowest tertile (OR: 2.33; 95% CI: 1.39, 3.89). This association remained significant after adjusting for multiple comparisons. There were no observed associations between other plasma carotenoids and any premenstrual symptoms. In summary, higher concentrations of beta-cryptoxanthin were associated with an increased appetite as a premenstrual symptom, but no associations were observed for any other carotenoid and for any other symptom.

Genetics of Iron Metabolism and Premenstrual Symptoms: A Mendelian Randomization Study

BACKGROUND

Many women of reproductive age experience adverse psychological and physiological premenstrual symptoms. These symptoms may last for most of the reproductive years and can negatively affect the quality of life of many women. Some studies have examined the role of micronutrients in premenstrual symptoms, but the research on iron has been limited.

OBJECTIVES

The objective of this study was to evaluate the effects of genetic predictors of iron overload and low iron status on premenstrual symptoms using Mendelian randomization.

METHODS

We examined 254 White females aged 20-29 y from the Toronto Nutrigenomics and Health Study. DNA was isolated from peripheral white blood cells and genotyped for the homeostatic regulatory iron gene (HFE; rs1800562 and rs1799945), transmembrane protease serine 6 (TMPRSS6; rs482026), transferrin receptor 2 (TFR2; rs3811647), and transferrin (TF; rs738584) polymorphisms. Risk of iron overload or low iron status was determined based on combined genotypes. Binomial logistic regressions were carried out to examine the association between genetic risk of iron overload or low iron status and the presence of premenstrual symptoms.

RESULTS

Compared with participants with typical risk of iron overload, those with an elevated risk of iron overload were less likely to experience premenstrual symptoms of confusion (OR: 0.13; 95% CI: 0.02, 1.00), headaches (OR: 0.28; 95% CI: 0.08, 0.98), and nausea (OR: 0.13; 95% CI: 0.02, 0.99) after adjusting for BMI, age, and vitamin C and calcium intake. No associations were seen with the other symptoms. There were also no associations between low iron status genotypes and premenstrual symptoms.

CONCLUSIONS

This Mendelian randomization study demonstrates that women with an elevated risk of iron overload may have a lower risk of experiencing some premenstrual symptoms (headache, confusion, and nausea), suggesting that iron status could impact the risk of certain premenstrual symptoms.

Vitamin D: A Pleiotropic Hormone with Possible Psychotropic Activities

BACKGROUND

After the recognition of the efficacy of cod-liver oil in rickets at the end of the eighteenth century, and the isolation and synthesis of the liposoluble vitamin D in 1931, its mode of actions and functions were deeply explored. Biochemical studies permitted to identify five forms of vitamin D, called D1, D2, D3, D4 and D5, differing in ultrastructural conformation and origin, with vitamin D2 (ergocalciferol) and D3 (cholecalciferol) representing the active forms. In the last decades especially, a constantly increasing bulk of data highlighted how vitamin D could regulate several activities and processes.

AIMS

The aim of the present paper was to review and comment on the literature on vitamin D, with a focus on its possible role in the pathophysiology of neuropsychiatric disorders.

DISCUSSION

Available literature indicates that vitamin D regulates a variety of processes in humans and in the central nervous system. Vitamin D deficiency is associated with an enhanced pro-inflammatory state, and formation of Aβ oligomers that might contribute to the cognitive decline typical of the elderly age and, perhaps, dementia. More in general, vitamin D is supposed to play a crucial role in neuroinflammation processes that are currently hypothesized to be involved in the pathophysiology of different psychiatric disorders, such as major depression, bipolar disorders, obsessive-compulsive disorders and psychosis.

CONCLUSION

It is conceivable that vitamin D supplementation might pave the way towards "natural" treatments of a broad range of neuropsychiatric disorders, or at least be useful to boost response to psychotropic drugs in resistant cases.

Insomnia, Inattention and Fatigue Symptoms of Women with Premenstrual Dysphoric Disorder

Aim: Premenstrual dysphoric disorder (PMDD) has predictable, cyclic, psychological, and somatic symptoms, such as sleep problems. They result in functional impairment, are aggravated in the late luteal phase of the menstrual cycle, and are resolved by menstruation. The present study evaluated the insomnia, inattention, and fatigue symptoms of PMDD and their fluctuations during the menstrual cycle. Methods: A total of 100 women were diagnosed as having PMDD based on psychiatric interviews and a prospective investigation of three menstrual cycles. A total of 96 individuals without PMDD were recruited as controls. Their symptoms, namely insomnia, inattention, and fatigue as well as functional impairment were assessed by using the premenstrual symptoms screening tool, the Pittsburgh insomnia rating scale, the attention and performance self-assessment scale, and the fatigue-assessment scale during both premenstrual and follicular phases. Results: In both the premenstrual and follicular phases, women with PMDD experienced more severe insomnia, inattentiveness, and fatigue than did women in the control group. A paired t-test demonstrated that women with PMDD had more severe severity insomnia, inattentiveness, and fatigue in the luteal phase than in the follicular phase. A repeated-measures analysis of variance demonstrated that the interaction period of PMDD and a menstrual cycle was significantly associated with insomnia, inattentiveness, and fatigue. A further correlation analysis demonstrated that all three symptoms were positively associated with self-reported functional impairment due to PMDD. Conclusions: Our results demonstrated that women with PMDD experienced an exacerbation of insomnia, memory problems, difficulty maintaining focus, and fatigue in the premenstrual phase. These symptoms are correlated with PMDD symptoms severity and functional impairment, and as such, they should be evaluated, and interventions should be employed in the late luteal phase of women with PMDD.

Is Premenstrual Syndrome Associated with Inflammation, Oxidative Stress and Antioxidant Status? A Systematic Review of Case-Control and Cross-Sectional Studies

Premenstrual syndrome (PMS) is a cyclically occurring combination of various symptoms, leading to decreased life quality among approximately 30% of women of childbearing age. PMS etiology remains unknown; however, there are some suggestions that inappropriate inflammatory response and oxidative stress are involved. This study aimed to systematically review case–control and cross-sectional studies investigating inflammation markers, oxidative stress, and antioxidant status among women with PMS and controls. The study protocol was registered with PROSPERO (no. CRD42020178545), and the authors followed the guidelines for performing a systemic review recommended by Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). By searching PubMed and Scopus databases (up to 8 January 2021), six case–control studies and five cross-sectional studies of medium or high quality were classified to the review. The systematic review included 652 women with PMS and 678 controls, for whom 36 eligible markers were determined. Limited evidence indicates increased levels of inflammatory parameters and suggests decreased antioxidant status in PMS women. Insufficient data with inconsistent results made it impossible to formulate a firm conclusion on the contribution of oxidative stress in PMS occurrence. To acknowledge the role of inflammation, oxidative stress, and antioxidant status in the pathophysiology of PMS, further research with case–control design and large study groups is needed.

The Association Between Vitamin D and Premenstrual Syndrome: A Systematic Review and Meta-Analysis of Current Literature

A number of studies have assessed the association between vitamin D and premenstrual syndrome (PMS) in different populations, but the findings have been inconclusive. Herein, we systematically reviewed available observational and interventional evidence to elucidate the overall relationship between vitamin D and PMS. PubMed, Cochrane Library, ScienceDirect, Scopus, Google Scholar, and ISI Web of Science databases were searched for all available articles until September 2018. The Newcastle-Ottawa quality assessment scale and Jadad scale were used to assess the quality of the observational and interventional studies, respectively. A total of 16 studies out of 196 met our inclusion criteria and were included in the final analysis. Although no significant association between serum 25(OH)D and PMS (weighted mean difference (WMD) = 3.35; 95% confidence interval, -7.80 to 1.11; p = 0.14) was indicated in observational studies, vitamin D supplementation was effective in ameliorating PMS symptoms based upon findings from interventional studies. These results add to the existing literature supporting the fact that nutrition, especially vitamin D, plays an important role in women's health. Additional well-designed clinical trials should be considered in future research to develop firm conclusions on the efficacy of vitamin D on PMS. KEY TEACHING POINTS 5-8% of women experience severe PMS. Nutrition especially vitamin D plays an important role in the women's health. Vitamin D could exert significant clinical effects on PMS symptoms. This is a systematic review and meta-analysis in this regard.