The associations between serum vitamin D, calcium and uterine fibroids in Chinese women: a case-controlled study

OBJECTIVE: To investigate the associations between serum vitamin D, calcium and uterine fibroids in a Chinese female population. METHODS: In this case-control study, adult female patients with fibroids (cases) were compared with females without fibroids (controls) in terms of serum 25-hydroxyvitamin D (25OHD) and calcium levels. RESULTS: Out of 546 total participants (mean age, 41.68 ± 5.99 years; 279 with fibroids and 267 without fibroids), only 232 had serum 25OHD levels above the sufficient threshold (>20 ng/ml). In addition, females with fibroids had lower serum 25OHD levels versus those without fibroids. The prevalence of fibroids in females with deficient (<12 ng/ml) and insufficient (12–20 ng/ml) 25OHD levels were significantly higher than in females with sufficient (>20 ng/ml) 25OHD levels. Serum calcium levels were within normal range in both groups. CONCLUSION: Hypovitaminosis D was highly prevalent among a population of Chinese females of reproductive-age, and serum 25OHD levels were lower in female patients with fibroids.