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Follicular fluid concentrations of the vitamin D metabolite 24,25(OH)2D3 are positively associated with live birth rate after assisted reproductive technology

Year: 2025

Type: article

Abstract: To investigate the relationship between concentrations of vitamin D metabolites in follicular fluid and outcome of assisted reproductive technology (ART) treatment. Prospective cohort study including 116 women undergoing in vitro fertilization (IVF) or intra cytoplasmic sperm injection (ICSI) treatment. All measured vitamin D metabolites 25OHD 3 , 1,25(OH) 2 D 3 and 24,25(OH) 2 D 3 are detectable in follicular fluid. Follicular fluid concentration of the 24,25(OH) 2 D 3 metabolite was higher than corresponding serum values, while the opposite phenomenon was observed for the 1,25(OH) 2 D 3 metabolite. Local conversion is plausible as the vitamin D activating enzymes (CYP2R1 and CYP27B1) as well as the vitamin D receptor (VDR) are highly expressed in the developing follicle. Women who achieved a live birth had 29 % higher 24,25(OH) 2 D 3 and 15 % higher 25OHD 3 concentrations in their follicular fluid (18 ± 7.9 versus 14 ± 6.2 nmol/L, p = 0.008 and 71 ± 22 versus 62 ± 18 nmol/L, p = 0.025, respectively) compared to women not achieving a live birth. Moreover, women with a low (≤ 15 %) follicular fluid 1,25(OH) 2 D 3 /24,25(OH) 2 D 3 ratio had a higher live birth rate compared to women with a medium (16–84 %) or high (≥ 85 %) ratio (live birth rate: 53 % vs 29 % and 12 %, respectively, p = 0.032). This study reveals that high levels of 24,25(OH) 2 D 3 and low levels of the 1,25(OH) 2 D 3 /24,25(OH) 2 D 3 ratio in follicular fluid are associated with increased live birth rates in women undergoing IVF/ICSI treatment. Conversion of vitamin D metabolites systemically or in the ovarian follicle may affect ART outcome. Further studies are warranted to support the findings from this pilot study and identify regulators of ovarian vitamin D metabolites. • The vitamin D metabolites 25OHD 3 , 1,25(OH) 2 D 3 and 24,25(OH) 2 D 3 are detectable in follicular fluid • Women who achieved a live birth had 15 % higher 25OHD 3 and 29 % higher 24,25(OH) 2 D 3 concentrations in their follicular fluid. • Low levels of the 1,25(OH) 2 D 3 /24,25(OH) 2 D 3 ratio in follicular fluid are associated with increased live birth rates.

Source: The Journal of Steroid Biochemistry and Molecular Biology

DOI: 10.1016/j.jsbmb.2025.106764