A dengue epidemic is one of the most important public health problems in the tropical and subtropical areas of the World. In 2005, 7,062 dengue cases were reported in Tamaulipas on Mexico's eastern coast, including 1,832 (26%) cases classified as Dengue Hemorrhagic Fever (DHF). Dengue fever (DF) is characterized by fever, intense headache, myalgias, arthralgias, rash, nausea and vomiting. A proportion of infected persons may develop DHF characterized by prominent hemorrhagic manifestations associated with thrombocytopenia. An immune mechanism of thrombocytopenia due to increased platelet destruction appears to be operative in patients with DHF. Excessive capillary permeability may lead to Dengue Shock Syndrome (DSS). Patients with DHF/DSS who also have prolonged fever (> 5 days) are at high risk for concurrent bacteremia. Standard treatment is limited to electrolytic solutions, rest, measurements of body temperature, blood pressure, hematocrit, platelet count, and administration of antipyretics like paracetamol when fever is too high. Extracellular calcium plays a key role in platelet aggregation and for the regulation of the immune response in personsinfected with Dengue Virus (DV), and dihydroxy-vitamin D has recently been found to alter IL-12 expression anddendritic cell maturation. We report the cases of five patients who received oral calcium carbonate plus Vitamin D3, who improved overall clinical condition and reduced the duration of signs and symptoms of DF.