The Impact of Vitamin D Levels on Oocyte Quality and Fertility Outcomes in Women Undergoing Assisted Reproductive Technologies (ART): Case Report

Sara A. Albibass; Abuagila A. Akra; Mohammed Said Elmahaishi; Hungarian Board

doi:10.58372/2835-6276.1410

Authors

Sara A. Albibass
Abuagila A. Akra
Mohammed Said Elmahaishi
Hungarian Board

DOI:

https://doi.org/10.58372/2835-6276.1410

Keywords:

vitamin D, oocyte quality, assisted reproductive technology, ICSI, folliculogenesis, meiotic maturation, vitamin D deficiency, ART outcomes, Libya, clinical pregnancy

Abstract

Background: Vitamin D deficiency is highly prevalent among women of reproductive age globally, with rates exceeding 60–80% in Libyan and MENA-region women despite year-round solar availability. VDR expression and both vitamin D–metabolizing enzymes (CYP2R1, CYP27B1) have been confirmed throughout the human ovarian follicle, establishing a direct biological basis for calcitriol activity in folliculogenesis and oocyte maturation. Despite the biological plausibility, no prospective randomized controlled trial has examined this relationship in a Libyan or North African ART population.

Objective: To evaluate the effect of oral vitamin D₃ supplementation on oocyte meiotic maturation stage, morphological grade, and clinical pregnancy rate in vitamin D–deficient infertile women undergoing ICSI at Yashfeen Fertility Center, Tripoli, Libya.

Methods: A prospective open-label randomized controlled trial enrolled 82 infertile women with confirmed vitamin D deficiency (serum 25[OH]D < 20 ng/mL by chemiluminescence immunoassay) between January and December 2025. Participants were randomly assigned 1:1 to an intervention group (n = 41) receiving oral vitamin D₃ 50,000 IU weekly for 12 consecutive weeks, or an unsupplemented control group (n = 41). Primary outcomes were oocyte meiotic staging (GV, MI, MII) and morphological grading (Grades I–III). The secondary outcome was clinical pregnancy rate. Data were analyzed with IBM SPSS v24; p < 0.05 was the threshold for significance.

Results: Mean participant age was 32.09 ± 5.18 years. Male factor infertility was the predominant etiology (50.0%), and 84.4% underwent the GnRH antagonist protocol. Vitamin D supplementation was associated with a significantly higher proportion of mature MII oocytes (p = 0.024), lower rates of immature GV-stage oocytes (p = 0.042), and reduced MI-arrested oocytes (p = 0.023). Morphological grading showed a significantly higher prevalence of Grade I oocytes (p = 0.001), higher Grade II prevalence (p = 0.003), and a significantly different Grade III oocyte distribution (p = 0.035) in the supplemented group. The clinical pregnancy rate was 36.6% (15/41) in supplemented women versus 19.5% (8/41) in deficient controls (p = 0.024), a 1.87-fold difference.

Conclusion: Correcting vitamin D deficiency prior to ICSI significantly improves oocyte meiotic maturation, morphological quality, and clinical pregnancy rates. Routine serum 25(OH)D assessment and targeted supplementation are recommended as part of the standard pre-ART workup, particularly in high-prevalence settings such as Libya. Larger multicenter, double-blind, placebo-controlled trials incorporating ploidy assessment and live birth as the primary endpoint are needed to confirm these findings.

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