The purpose of present study was evaluating the influence of core stability exercise and vitamin D on some of physical fitness indices in young multiple sclerosis (MS) women.36 relapsing remitting MS women with EDSS≤3 (age: 32.72±6.57y, height: 164±4.23 cm, weight: 65.1±11.4 kg, disease duration: 4±1.20) participated in the study voluntarily and were divided randomly to four groups including three experimental groups of supplementations (SUP), exercise, SUP+ exercise and one control group. Before and after experimental period, all subjects participated in exercise tests including back muscle extensor strength test using dynamometer, muscular endurance of trunk using keeping trunk in angle of 60-degree, flexibility using Velez test, coordination test by repeated throwing of tennis ball, balance test using one leg stance. Core stability exercise was performed during 8 weeks and 3 times a week progressively (first session: keeping the motion for 5 S, with 6 repetitions, last session keeping the motion for 8 second with 10 repetition). Supplementation groups consumed 1500 IU vitamin D every two weeks. Statistical test of Analysis of Covariance was used for data analysis. Findings of the study indicated that inSUP+exercise group compared to control group significant increasing was observed in muscle strength (P=0.002) and endurance (P=0.001), flexibility (P=0.001) coordination (P=0.001) and balance (P=0.001), and compared to SUP significant increasing was found in muscle endurance (P=0.001), flexibility (P=0.001), coordination (P=0.001) and balance (P=0.001). Exercise (without SUP) compared to SUP caused increasing of muscle endurance (P=0.015), and compared to control group improved muscle endurance (P=0.02), coordination (P=0.031) and balance (P=0.001). SUP by itself did not cause any significant improvement in none of variables (P>0.05).According to priority exercise+SUP and exercise indicate positive influence on improving physical fitness indices.