Mitochondrial disease patients' perception of dietary supplements' use.

Surveys of mitochondrial disease physicians conducted through the Mitochondrial Medicine Society have shown that virtually all providers recommend a variety of dietary supplements as treatments to their patients in an effort to enhance energy production and reduce oxidative stress. In this survey, we asked patients and their parents about their experiences taking these dietary supplements for mitochondrial disease. The survey was disseminated through the North American Mitochondrial Disease Consortium (NAMDC) and the Rare Disease Clinical Research Network (RDCRN) registries and gathered 162 responses. The study ascertained each patient's mitochondrial disease diagnosis, dietary supplements used, adjunct therapy, and effects of the supplements on symptoms and health. Regardless of the specific underlying mitochondrial disease, the majority of the survey respondents stated they are or have been on dietary supplements. Most patients take more than four supplements primarily coenzyme Q10, l-carnitine, and riboflavin. The majority of patients taking supplements reported health benefits from the supplements. The onset of perceived benefits was between 2weeks to 3months of initiating intake. Supplements seem to be safe, with only 28% of patients experiencing mild side-effects and only 5.6% discontinuing their intake due to intolerance. Only 9% of patients had insurance coverage for their supplements and when paying out of pocket, 95% of them spend up to $500/month. Despite the use of concomitant therapies (prescribed medications, physical therapy, diet changes and other), 45.5% of patients think that dietary supplements are the only intervention improving their symptoms. Some limitations of this study include the retrospective collection of data probably associated with substantial recall bias, lack of longitudinal follow up to document pre- and post-supplement clinical status and second hand reports by parents for children which may reflect parents' subjective interpretation of symptoms severity and supplements effect rather than real patients' experience. More extensive prospective studies will help further elucidate this topic.