Functional food is usually defined as the foods with one or more essential nutrients that provide the best opportunities for health, well-being, and reduced risks of diseases. Vitamin D is a nutrient that its deficiency in recent years in developing countries as well as, Iran. Vitamin D refers to a group of steroid compounds with anti-rickets effect. The most important natural forms of this vitamin are vitamin D3 (cholecalciferol) and vitamin D2 (Ergocalciferol).The Recommended Daily Intake (RDI) of Vitamin D3 is 400 International Unites per day. The main roles of vitamin D3 calcium and phosphor absorption in body and supporting bone, as well as prevents the onset of many diseases such as rickets, osteoporosis or osteoporosis, the disease MS, colon cancer and etc. vitamin D3 originates from 7-dehydrocholesterol when synthesized in the skin following exposure to UV, but various limitations is caused deficiency of this vitamin in the body. The simplest way to compensate is the addition of vitamin D3 to food. Vitamin D3 is sensitive to light, high temperatures, oxygen and acidic media. Encapsulation is a strategy to increase the efficacy and application of a large variety of natural functional compounds and delivery systems. Among different food, bread is suitable as a carrier for vitamin D3 due to being the staple food and is the main food of the low-income people. In this study, the functional bread is produced by microcapsules containing vitamin D3. Alginate is used as the primary coating to encapsulate of vitamin D3 and to optimize the encapsulation process, Response surface methodology (RSM) in three variables of alginate percentage, the ratio of the vitamin to alginate percentage and ultrasonic time at three levels are used. The results showed that maximum encapsulation efficiency (92/86%) and loading capacity (30/1%) are achieved in 0/23% alginate percentage, 1:5 ratio of the vitamin to alginate percentage and 13/7 min ultrasonic time. After optimizing, alginate capsules were coated by chitosan. The morphological characteristics of microcapsules are investigated by SEM. FTIR spectra from the microcapsules of vitamin D3 is showed that the peak at 1453 cm?1 of alginate after loading and also interaction with chitosan, the intensity of the peak is sharper and shifted by a few cm–1.The modeling and release profile of alginate and Alginate-chitosan hydrogels contains vitamin D are conducted in simulated gastric (SGF) and intestinal fluid (SIF), the highest release of Alginate microcapsules (93% of the initial amount of vitamin D3) is in SIF And with second coating reduced from 93 to 71%. Results showed that water absorption, development time, stability time were increased, whereas Degree of softening and Mixing tolerance index decreased by adding microcapsules to bread dough. The characteristics of bread were investigated after the addition of microcapsules. This addition caused a reduction in the specific volume and weight loss during baking of the bread. The result of texture profile analysis (TPA) showed that the addition of alginate microcapsules increased Hardness, Gumminess, and Chewiness of the bread. The image analysis indicated that fortification bread with alginate microcapsules caused the increase of the density and decrease of the porosity. Color measurement of bread showed that the crumb and crust of bread become brighter with adding alginate microcapsules comparing to control bread. Overall acceptability of functional bread produced was lower. The vitamin D3 loss during baking and storage of fortified bread with alginate-chitosan showed less than the control samples. So alginate-chitosan suitable coating for encapsulation of vitamin D.