Highly prevalence of vitamin D deficiency among Brazilian women of reproductive age

Vinicius Medina Lopes, Joaquim Roberto Costa Lopes, Jean Pierre Barguil Brasileiro, Ingrid de Oliveira, Ricardo Peclat Lacerda, Marcos Renato Dib Andrade, Natália Ivet Zavattiero Tierno, Roberto Costa Cavalcante de Souza, Luiz Augusto Casulari Roxo da Motta

Vitamin D has several metabolic functions and possible reproductive functions. This study aimed to determine the prevalence of vitamin D deficiency among Brazilian women of reproductive age, and to evaluate the relationship between serum 25-hydroxyvitamin D [25(OH)D] concentrations and infertility causes. This retrospective cross-sectional study evaluated data from a private Brazilian assisted reproduction center that were collected between January 1 and May 5, 2012. Serum 25(OH)D concentrations were measured and compared for infertile and fertile women. Concentrations of 25(OH)D that were < 20 ng/mL were defined as deficiency and concentrations of 21-30 ng/mL were defined as hypovitaminosis D. Among the 369 evaluated women, 81.1% exhibited hypovitaminosis D and 32.0% exhibited deficiency. The infertile and control patients did not exhibit any significant differences in the prevalence of vitamin D deficiency (30.2% vs. 35%, respectively; p = 0.33) or in the mean 25(OH)D concentrations (24.3 ± 7.9 ng/mL vs. 23.8 ± 8.7 ng/mL, respectively; p = 0.51). Furthermore, there were no significant differences in the mean 25(OH)D concentrations among subgroups of patients with single infertility factors, or between these subgroups and the control group. A high proportion of Brazilian women of reproductive age exhibited vitamin D deficiency, regardless of their fertility status. Thus, it may be useful to evaluate this population for vitamin D deficiency, although future studies are needed to determine whether this deficiency might affect the outcomes of treatments for infertility.