The Investigation of Vitamin D and Menstrual Cycles Trial (the inVitD Trial): A clinical trial of vitamin D supplementation on the hypothalamic-pituitary-ovarian axis.

ABSTRACT:

Background

While there is evidence that vitamin D deficiency is associated with long menstrual cycles, delayed ovulation, and reduced fertility, it is yet unknown if increasing vitamin D levels can regulate menstrual cycles, and thus possibly improve fertility. The primary objective of this randomized clinical trial (RCT) is to test the hypothesis that vitamin D supplementation influences the hypothalamic-pituitary-ovarian axis.

Methods

This two-site RCT (NCT05050916) required participants to be aged 19-40 years old, having spontaneous menstrual cycles, and without certain chronic diseases or contraindications for vitamin D supplementation. At baseline participants provided information on their demographics and health history. Blood was drawn at the first clinic visit after

SUBMITTER: Klawans MR 

PROVIDER: S-EPMC12766629 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature