Tobechukwu Chigha Iyidobi, Theclar Ogochukwu Iyidobi, Chisom Oscar Uzuegbunam, Emmanuel Chino Iyidobi
Cardiovascular disease (CVD) is a leading cause of global mortality, accounting for approximately 17.3 million deaths annually. The antioxidant effects of certain micronutrients may play a role in CVD prevention. This systematic review critically evaluates the evidence on antioxidant vitamins (C, E, carotenoids), B-complex vitamins, vitamin D, trace minerals (iron, copper, zinc, selenium), and electrolytes (sodium, potassium, magnesium, calcium) in cardiovascular health. This scoping review with narrative synthesis was informed by PRISMA principles. PubMed, Scopus, Cochrane Library, and Google Scholar were searched (1980-2024) for English-language human studies on micronutrients and cardiovascular outcomes. Study selection involved screening, full-text review, and snowballing. Quality was assessed through critical appraisal. Data were synthesised thematically. Approximately 70 key studies were included from over 200 identified references. Antioxidant vitamins show inconsistent benefits, with some cohorts demonstrating 27-47% risk reductions despite null RCT results. Vitamin D deficiency (30-50% prevalence) is consistently associated with CVD risk, though supplementation trials are mixed. B-vitamins improve endothelial function via homocysteine reduction. Trace minerals demonstrate biphasic relationships, where both deficiency and overload increase CVD risk. Electrolyte balance, particularly the sodium-potassium ratio, critically determines blood pressure and cardiovascular outcomes. Current evidence does not support universal supplementation. The complex relationships between micronutrient status and CVD outcomes underscore the need for personalized approaches.