NIH convened a workshop to address the evidence base for nutritional interventions in primary mitochondrial disease (PMD).

Dietary supplements are commonly used as management modalities for PMD despite limited evidence of safety and efficacy.

PMD are rare, clinically, phenotypically, and genetically heterogeneous, a challenge to conducting clinical trials.

Resources to support clinical trials include patient registries and biorepositories, and common data elements.

Future research is needed to define the diseases; identify biomarkers, outcome measures, and endpoints.