Effectiveness of vitamin-B supplements on cognition in older adults: A meta-analysis

We aimed to investigate the efficacy of B-vitamin and folic acid supplementation in slowing down cognitive function decline among older adults. We searched databases for trials comparing B-vitamin and folate supplementation versus placebo in older adults identified with or without impaired cognition. 23 articles were eligible and included in this meta-analysis. The mean difference (MD) in homocysteine levels was significant between the compared groups (MD:-4.52; 95%CI:-5.41 to 3.63, P < 0.001). However, the difference in the Mini-Mental State Examination (MMSE) was non-significant between the compared groups with or without cognitive impairment (MD:0.19; 95%CI: −0.148 to 0.531, P = 0.27), and (MD:0.04; 95%CI:−0.1 to 0.18, P = 0.59), respectively. The difference in Clinical Dementia Rating-sum of box (CDR-SOB) scores was non-significant (MD:-0.16; 95%CI:−0.49 to 0.18; P = 0.36). B-vitamin and folate supplementations significantly reduced homocysteine levels. However, it failed to provide significant benefits over placebo in preventing or slowing the decline in cognitive function.