Vitamin D and uterine leiomyoma among a sample of US women: Findings from NHANES, 2001-2006.

Scientific understanding of the etiology of uterine leiomyomata (UL) remains incomplete, but recent investigations have suggested an association between low Vitamin D and UL risk. In this study, we conducted a cross-sectional analysis of Vitamin D exposure, measured using serum levels of 25(OH)D (a Vitamin D metabolite), and self-reported UL diagnosis among 3590 women aged 20-54 in the National Health and Nutrition Examination Survey (NHANES 2001-2006). Multivariate logistic regression models comparing each quartile of 25(OH)D to the lowest quartile indicated no relationship between 25(OH)D and odds of UL in the whole population (Ptrend=0.37), or in sensitivity analyses. However, a probabilistic analysis correcting outcome misclassification indicated that insufficient 25(OH)D was associated with UL in white (Odds ratio (OR) median estimate: 2.17; 2.5, 97.5 percentiles: (1.26, 23.47)), but not black women (OR median estimate: 1.70; 2.5, 97.5 percentiles: (0.89, 3.51)), suggesting misclassification may have driven some of the null findings.