Vitamin D3 Cosupplementation with Eicosapentaenoic Acid and Docosahexaenoic Acid: A Molecular, Clinical and Regulatory Perspective.

EPA, DHA, and vitamin D3 are pivotal micronutrients, with well-established roles in maintaining physiological function and preventing disease. This comprehensive review explores their individual molecular pathways and synergistic interactions that arise from their cosupplementation. This review synthesizes evidence from a spectrum of sources, including foundational preclinical studies and large-scale randomized controlled trials, to elucidate the efficacy and safety across various health conditions, including cardiovascular disease, metabolic disorders, immune modulation, neurological health, and bone/joint disorders. A critical assessment of landmark trials reveals that although individual supplementation may not yield broad primary prevention benefits in a general population, significant reductions in myocardial infarction and autoimmune disease incidence emerge in specific, targeted subgroups. Furthermore, the review addresses the global regulatory landscape and surveillance strategies established by key authorities, including the United States Food and Drug Administration, the European Food Safety Authority, and the Food Safety and Standards Authority of India, highlighting the critical role of these frameworks in ensuring product quality, safety, and consumer protection. The review concludes that the field necessitates further research into optimal dosing, long-term effects, and the precise molecular mechanisms of their complex interplay to guide future clinical practice and public health policy.