Introduction: There is a high prevalence of vitamin deficiency in our healthy population; however, age-related cognitive decline is an emerging global health concern, especially with an aging population and rising cases of dementia. Many trials have been performed to assess the improvement in cognitive functions of people, especially those of older age, by daily multivitamin supplementation. Studies have shown that daily multivitamin intake significantly improves memory in older adults and reduces the risk of cognitive decline. Methods: A comprehensive search was conducted across PubMed, Embase, and Google Scholar databases from 2003 to 2023. Studies were included based on predefined PICO criteria, focusing on older adults with cognitive decline receiving multivitamin supplementation compared to placebo, with cognitive improvement as the outcome. Nineteen studies meeting the inclusion criteria, comprising randomized trials, reviews, cohort, and cross-sectional designs, were analyzed. Results: The findings reveal mixed outcomes. Multivitamin supplementation was associated with cognitive improvements, particularly in memory, global cognition, and attention, mainly in individuals with baseline deficiencies or mild cognitive impairment. B-complex vitamins and antioxidant-rich formulas showed the most promising effects. However, in well-nourished or healthy populations, results were often neutral. Variability in study design, supplement composition, assessment tools, and duration were key contributors to these inconsistencies. Conclusion: The use of multivitamins shows potential cognitive benefits in specific subgroups, particularly the elderly with nutritional deficiencies or early cognitive decline. However, universal cognitive enhancement cannot be concluded. Personalized, targeted supplementation guided by nutritional status may represent the future of cognitive health strategies.
Daniyal et al. (Tue,) studied this question.