Background: Vitamin D deficiency is a widespread problem especially in females. The presence of different vitamin D preparations (oral, parenteral) with no definite evidence about the most appropriate method for vitamin D deficiency treatment aroused the need for more studies about the most effective route. Aim: To evaluate the oral vitamin D preparation compared to intramuscular (IM) vitamin D preparation in correcting vitamin D deficiency in affected women. Subjects and methods: This is an interventional research performed on obese female patients diagnosed with vitamin D deficiency in the 2019–2022 timeframe for outpatient clinics at Zagazig University Hospitals. Eighty females were included in the study. They were allocated randomly into 2 equal groups (40 females per group); oral group and injection groups, based on their preference. Pre and post intervention assessment was done by assessing the level of serum vitamin D. Results: There was statistically insignificant difference among studied groups concerning vitamin D level before therapy, while there was significant difference between them after therapy, where oral group had significantly higher level. Within each group, there was significant increase in vitamin D level after therapy. There was statistically significant positive correlation between percent of increase in vitamin D and both age and body mass index (BMI) of patients in the oral group, but no significant correlation was detected in injectable group between age and percent of change. Conclusion: Treatment for vitamin D insufficiency works well when administered intramuscularly and orally but oral group showed more improvement.