Early-onset climacterium is not associated with impaired vitamin D status: a population-based study

Objective: To investigate vitamin D status in women with the onset of the climacteric phase by age 46 as both early menopause and inadequate vitamin D status may increase the risk of adverse health outcomes. Methods: A cross-sectional study included 2,544, 46-year-old women from a birth cohort. Women were divided into the following two groups according to their menstrual history and follicle-stimulating hormone (FSH) concentration: 1) climacteric (FSH >= 25 IU/L and amenorrhea >= 4 mo, n = 351) and 2) preclimacteric women (FSH <25 IU/L and having regular/irregular menstrual cycles, n = 2,193). Serum 25-hydroxyvitamin D (25(OH)D) concentrations were compared between the groups. A linear regression model was performed to investigate which factors are associated with 25(OH)D status. Results: Mean serum 25(OH)D concentrations were higher in climacteric compared with preclimacteric women (68.1 +/- 19.8 nmol/L vs 65.2 +/- 19.3 nmol/L, P = 0.01). However, in the linear regression model, climacteric status was not associated with 25(OH)D status (multivariable adjusted mean difference 4.5 nmol/L, 95% confidence interval -1.4 to 10.4, P = 0.137). A total of 76 of the climacteric women were using systemic estrogen hormone therapy (HT). In a subanalysis, including only climacteric women, the use of HT was associated with higher 25(OH)D status (multivariable adjusted mean difference 5.9 nmol/L, 95% confidence interval 1.3-10.5, P = 0.013). Conclusions: The onset of the climacteric phase by age 46 was not associated with inadequate 25(OH)D concentrations, whereas HT use was associated with higher 25(OH)D status in women with early-onset climacterium.