The association between serum levels of vitamin D and recurrent urinary tract infections in premenopausal women

Objectives: To examine whether there is any association between serum levels of 25-hydroxy vitamin D (25(OH) vitamin D) and the recurrence of urinary tract infections (UTIs) among premenopausal women.

Methods: During a period of 3 years, 93 premenopausal women with a medical history of recurrent UTIs were enrolled from the Infectious Diseases Unit. Cases with recurrent UTIs were compared to 93 age-matched (±5 years) women with no history of recurrent UTI (control group), in terms of serum 25(OH) vitamin D and different risk factors for recurrent UTI. Recurrent UTI was defined as three or more episodes of UTI over a 12-month period.

Results: The mean age of women with recurrent UTIs was 43.8±9 years and of controls was 39±10 years (p=0.839). The mean serum levels of 25(OH) vitamin D among women with recurrent UTIs were significantly lower than those of controls (9.8 ng/ml±4 vs. 23 ng/ml±6; p<0.001). Multivariate analysis showed that a serum 25(OH) vitamin D level of <15 ng/ml (odds ratio 4.00, 95% confidence interval 3.40-4.62; p=0.001) was associated with recurrent UTIs in premenopausal women.

Conclusions: In this retrospective study, we found that recurrent UTIs in premenopausal women are associated with vitamin D deficiency.