The number of poorly soluble drugs has significantly increased during the past ten years. The existing marketed product for Vitamin D3 is available in tablets, soft gelatin capsules, capsules, sachets, liquid, and powder in a sachet dosage form. In all these existing products, the overages are added upto 50%. The major reason for the addition of overages is the degradation of Vitamin D3. The present pharmaceutical composition and a process for preparing the same without any overages. Vitamin D3 capsules for the 2000IU are prepared by Self-Nano Emulsifying Drug Delivery System technology when the hydrophilic solvent system comes in contact with the hydrophobic precursor. Poloxamer 188, Sorbic acid, and BHT are the integral ingredients used for the stabilization of Vit.D3. A developed formulation is stable in accelerated, intermediate, and long-term stability. The role of antioxidant and preservative has an integral role in the stabilization of Vitamin.D3 formulation. The prepared formulation when dissolved in water leads to the formation of a transparent solution containing the drug particles less than 100nm, which is readily absorbed in the body fluid. The stability data and extrapolation reveals that Vit.D3 formulation is stable in the Accelerated stability testing, Intermediate Stability testing and long term stability testing conditions as per ICH guidelines for various attributes like weight variation, disintegration assay, and dissolution.