Background: An early menopause (by definition, menopause that occurs at a woman’s age 40 through 45) is often associated with certain changes in the body that can result in risks for health-related conditions, an extended period later. Thus, scientists have begun examining how vitamin D has been suggested to be associated with endocrine function regulating both hormones and reproductive function during this time. However, it is not yet clear as to whether or not vitamin D provides any benefit to women who have experienced an early menopause. Material and Methods: The data was collected from 272 women in this retrospective, observational study at The County Hospital, Department of Obstetrics and Gynecology, Arad. The method of grouping the sample included two stratifications into early and physiological menopause categories based on amenorrhoea for a minimum of 12 consecutive months. 25-hydroxyvitamin D (25(OH)D) levels were classified into three categories: deficiency (<20 ng/mL), insufficiency (21–29 ng/mL), or adequacy (≥30 ng/mL). Estradiol, progesterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) hormone parameters were measured using standard immunoassays. The analysis employed correlation and regression to evaluate potential relationships between 25(OH)D levels and hormone parameters. Results: A significant proportion of the study group had a vitamin D deficiency. This was supported by the fact that only 24.27% of women were identified as having adequate levels of vitamin D, while the rest (62.03%) did not. Women in the early menopause group had a statistically significant negative relationship between estradiol and FSH (i.e., r = −0.29, p = 0.0016), as well as between progesterone and LH (i.e., r = −0.207, p = 0.026). There was not a statistically significant relationship between total sample vitamin D and estradiol (i.e., r = −0.038, p = 0.686) nor between vitamin D and progesterone (i.e., r = 0.031, p = 0.744). Women with vitamin D blood levels of 30 ng/mL or more showed a strong negative relationship between vitamin D and estradiol (r = −0.780; p = 0.0016) and a moderate positive relationship with progesterone (r = 0.534; p = 0.0104). However, these relationships were inconsistent in other groups. All group comparative analyses showed that women in the early menopause group had much lower estradiol levels than those in the physiological menopause group, regardless of whether they were classified based on their vitamin D levels (p < 0.0001). Conclusions: Women experiencing early or physiological menopause are at risk of having low vitamin D levels. However, our study results do not show a consistent relationship between serum 25(OH)D concentrations and serum estradiol or progesterone concentrations among the study population, suggesting that vitamin D is not a major factor influencing hormonal changes during menopause. These findings were inconsistent across analyses and should be interpreted cautiously. Overall, the results do not support a significant association between serum 25(OH)D concentrations and reproductive hormone levels in our study population.

Background: The adverse cardiometabolic outcomes that have been associated with early menopause include obesity, insulin resistance, and metabolic syndrome. Other studies have also linked metabolic dysfunction with vitamin D deficiency. However, the independent association of serum 25-hydroxyvitamin D [25(OH)D] concentrations with metabolic syndrome and type of menopause is unclear. Thus, the present study was designed to assess the association between vitamin D status and metabolic syndrome in women with early menopause compared with those with natural menopause. Methods: A total of 301 postmenopausal women were enrolled. Metabolic syndrome was assessed independently according to the NCEP-ATP III and IDF diagnostic definitions. They were classified into two groups: early menopause (EM, n = 79) and physiological menopause (PHYSM, n = 222). Demographic, anthropometric, biochemical, and lifestyle characteristics were recorded. The criteria for diagnosing metabolic syndrome were those of the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) and the International Diabetes Federation (IDF). Serum 25(OH)D was also categorized as deficiency, insufficiency, or sufficiency. Multivariable logistic regression analyses were used to determine independent predictors of metabolic syndrome. Multivariable linear regression analyses were used to determine the association between serum 25(OH)D and individual metabolic parameters. Results: Women with early menopause had a higher body mass index than those with physiological menopause, whereas current smoking was more prevalent among women with physiological menopause. No significant differences were observed between the groups in the prevalence of metabolic syndrome, 25(OH)D concentrations, lipid profile, blood pressure, glycaemic indices, or other biochemical parameters. In multivariable analyses, menopausal status was not independently associated with metabolic syndrome according to either the NCEP-ATP III or IDF criteria. Body mass index was the only independent predictor of metabolic syndrome in the adjusted IDF model (OR 1.2, 95% CI 1.0–1.4; p = 0.047). Serum 25(OH)D concentrations were independently associated only with lower fasting glucose levels and were not independently associated with metabolic syndrome or its other components. Although vitamin D categories showed significant associations with metabolic syndrome in unadjusted analyses, these associations were attenuated after adjustment for demographic, anthropometric, menopausal, and lifestyle-related factors. Conclusions: Menopausal type was not independently associated with the prevalence of metabolic syndrome or vitamin D status. Although metabolic syndrome prevalence differed across vitamin D categories in unadjusted analyses, these associations were attenuated after adjustment for demographic, anthropometric, menopausal, and lifestyle-related factors. Obesity appeared to be the strongest independent predictor of metabolic syndrome within this cohort. Given the retrospective observational design, these findings should be interpreted cautiously, and prospective longitudinal studies are warranted to confirm these associations.