Abstract
Objective: this study was set up to assess the role of vitamin D on the female fertility using albino rats in order to get benefit from its use
Methods &Measurements: For this study, fifty female albino rats obtained as weanling (21 days –old) weighing 30 g , were allocated randomly into 2 equal groups ( First group was vitamin D-deficient rats which fed vitamin D deficient diet and the second group is vitamin D-replete rats which fed the same diet but received 2µg cholecalciferol per week in 0.1ml propylene glycol by a single intra peritoneal injection). A animals were maintained till become adult. The body weight was recorded from the age of 21 till the age of 4 months, the length and regularity of estrus cycle were monitored daily by vaginal smears , sera were used for determination of estrogen level. Tissue samples (ovaries and uteri) were used for histopathological examination.
Results: the obtained results showed a significant increase in the body weights of the replete females as compared with the deficient group. Moreover, the deficient females had longer days of estrus cycle. Estradiol level in the deficient females was lower than the replete females. Histopathological examination of the ovary showed abnormal development of the follicles, while uterine hypoplasia was recorded in the deficient females as compared with the replete one.
Conclusions: Vitamin D are capable of inducing useful effects on the reproductive systems of female rats .

Key words: Key words: Vitamin D, Estrus cycle, Estradiol, fertility, Female rats