comparison of vitamin d and zinc levels in women with diminished ovarian reserve compared to normal condition: a case-control study

Introduction: to date, limited studies have evaluated the relationship between serum levels of vitamin d, zinc and ovarian reserve, which have presented contradictory results.objective: this study aims to compare vitamin d and zinc dietary intake and serum levels in iranian women with diminished ovarian reserve (dor) compared to normal peers.materials and methods: the case-control study was performed on 99 women referred to an infertility treatment clinic in yasuj, iran, who were selected by a convenience sampling method. the case group (n=55) included women with dor (anti-müllerian hormone (amh) <1 ng/ml and antral follicle count (afc) <10 in sonography at 3-10 days of menstrual cycle). the control group (n=44) was women with normal ovarian reserve markers. dietary intake was assessed using the food frequency questionnaire, and the serum concentration of zinc and vitamin d were determined for each participant. the obtained data were analyzed using t-test or chi-square test. the body mass index (bmi) and age were adjusted by the analysis of covariance. significance level was set at p≤0.05.results: the mean age of the participants was 33.4±26.58 and 32.4±31.16 years in the case and control groups, respectively. the mean bmi of participants was 27.15±3.97 and 26.35±4.23 kg/m2 in the case and control groups, respectively. after adjusting for bmi and age, dietary intake of vitamin d (6.98±0.57 vs 4.02±1.09; p=0.05; adjusted effect size=0.86) and serum vitamin d level (20.91±5.23 vs 17.12±8.73; p=0.05; adjusted effect size=0.52) levels were significantly higher in the control group compared to the case group. dietary intake of zinc (8.75±2.55 vs 10.68±4.75) and serum zinc level (87.09±10.02 vs 87.09±10.02) were not significantly different in the control group compared to the case group, after adjusting for bmi and age.conclusion: our results on dor revealed the possible favorable relationship of vitamin d intake and serum vitamin d level with ovarian reserve performance, and this relationship is independent of age and bmi. further studies, particularly clinical trials, are recommended to clarify the potential positive effects of vitamin d on ovarian reserve in dor women.