Association between serum 25-hydroxy vitamin D level and menstrual cycle length and regularity: A cross-sectional observational study

Abstract

Background: Research examining the role of vitamin D deficiency and the development of menstrual disorders in women is of widespread interest. Studies have been published showing that supplementation with high-dose vitamin D can lead to the restoration of the menstrual cycle. We lack adequate information regarding the effect of vitamin D levels on the physiology of menstruation and further on fertility in women of reproductive age due to the contradictory results reported by studies.
 Objective: To study the association of 25-hydroxy vitamin D with menstrual cycle characteristics including long and short cycle length and cycle irregularity.
 Materials and Methods: In this cross-sectional study, serum vitamin D levels of 166 women attending an outpatient department with menstrual irregularities after excluding all obvious causes of menstrual disorders (n = 83) between April-June 2019 were measured and were compared with women of similar profiles with complaints other than menstrual irregularities (n = 83).
 Results: A decreased level of vitamin D was associated with a 13.3 times odds of an irregular cycle (OR (95% CI): 13.30 (5.79-30.60), p < 0.001). 25-hydroxy vitamin D was not associated with age or body mass index. We found a significant difference (p < 0.001) in mean vitamin D levels among the females with irregular cycles vs. regular cycles.
 Conclusion: Vitamin D plays a role in the physiology of reproduction specific to the menstrual cycle and ovulation. Long-term prospective studies assessing the exact cutoff value and the exact dose of supplementation required are needed.
 Key words: Menstrual disturbances, Ovulation, Reproductive period, Vitamin D deficiency, Dietary supplements, Polycystic ovarian syndrome.

role of adequate vitamin D levels in the menstrual cycle of reproductive-age women

“…Ultimately, 16 eligible studies were assessed, and eight of these were included for a full review. 14,17,20,[24][25][26][27][28] Articles were excluded for the following reasons: duplicate paper, irrelevant title, wrong study design and population based on abstracts, and wrong outcomes based on full-text review. Figure 1 illustrates the overall process of the study selection.…”

“…Six of the eight reviewed studies were observational studies. 14,17,20,24,27,28 and the rest were randomized control trials (RCTs). 25,26 The studies included a range of 60 to 1,133 women aged 12 to 55 years.…”

“…however, insufficiency status contributed with high risk of prolonged menstrual cycle. 24 Singh et al 28 found the vitamin D status on 166 women 18-40 years who have menstrual irregularities on cross-sectional study and showed a decrease in 25(OH)D levels was correlated with a higher risk of irregular menstrual cycles. Vitamin D intake normalized the 25(OH)D levels of the participants (12-18 years) and normal menstrual length (p=0.015).…”