Vitamin D as a risk factor for the presence of asymptomatic uterine fibroids in premenopausal Han Chinese women

Objectives: To investigate the relationship between vitamin D deficiency and the risk of asymptomatic uterine fibroids (UFs). Design: Cross-sectional study. Setting: University hospital. Patient(s): The present analysis recruited 133 asymptomatic patients with UFs and 80 normal control subjects from October 2017 to June 2020. Age matching created 61 pairs. Intervention(s): Medical history, transvaginal or transabdominal genital ultrasound scan, blood sampling, and measurement of vitamin D concentrations. Main Outcome Measure(s): Evaluation of the impact of vitamin D level on the risk of newly diagnosed asymptomatic UFs in premenopausal Han Chinese women. Result(s): Vitamin D levels of UF-positive patients were lower than those of healthy control subjects in unmatched samples (12.1 ng/mL vs. 16.8 ng/mL) and in matched samples (11.4 vs. 17.5 ng/mL). Younger patients (≤40 years) had a lower vitamin D level than older subjects in healthy control group (15.1 ng/mL vs. 19.0 ng/mL). We did not observe any age–vitamin D interactive effect in unmatched samples. Multivariate logistic regression revealed that asymptomatic patients presented a lower level of vitamin D than did normal groups in both unmatched and matched sample. In addition, the optimal threshold vitamin D level for having asymptomatic UFs was 14.34 ng/mL. Conclusion(s): Vitamin D deficiency may be associated with increased risk of asymptomatic UFs in premenopausal Han Chinese women.