Health Information Systems (HIS) rely on correlation of heterogeneous data sources, which are often closed and in proprietary formats. Moreover, studies conducted to process and link such data sources are based on corpora and databases in the English language. This hinders an adaptation to non-English speaking countries, not only because of the language but also due to the lack of authoritative integrated bases in these countries - such as Brazil, in which our research is being conducted. To help solve these issues, we have designed and implemented a set of modules to create consolidated curated open data sources, in Portuguese, thereby helping health data interoperability for HIS in Brazil. The resulting database, called HealDB, created from public authoritative sources, provides data on diseases, symptoms, medications and their indications, and drug-drug and drug-food interactions. All data are in Portuguese, and consonant with medications, indications and treatments officially approved by the Brazilian Ministry of Health. We have moreover created an ontology, still in a prototypical stage, to allow linking different attributes and sources, and support connection to additional data, thereby facilitating HIS interoperability.