Vitamins, Trace Elements, and Antioxidant Status in Dementia Disorders

Abstract

Antioxidants, such as vitamins C and E, have been proposed for the treatment of dementia disorders. Although other vitamins and trace elements may also have antioxidant-enhancing activities, it is not known whether the overall antioxidant status in dementia patients is associated with the intake level of these vitamins and trace elements. In this study, we assessed the levels of vitamins and trace elements in the diet of patients with Alzheimer's disease (AD), vascular dementia (VaD), and dementia with Lewy bodies (DLB) and a group of carers, along with blood levels of total antioxidant capacity (TAC). Results show that the dietary intake was decreased for most measured vitamins and trace elements in severe AD, but not in other dementia groups. In addition, we found no significant difference in the levels of TAC between any of the dementia groups. There was, however, a significant correlation between intake of vitamin B₁, vitamin B₁₂, zinc, and selenium and blood levels of TAC in the VaD group, but not in the AD and DLB groups. Furthermore, no association was observed in any of the dementia groups between zinc and copper intake and Cu/Zn superoxide dismutase activity, or between dietary selenium intake and glutathione peroxidase activity. The activities of these two endogenous antioxidant enzymes do not seem to be influenced by intake levels of relevant substances. The data indicate that the influence of dietary vitamins and metal ions on the overall antioxidant status is limited to VaD patients only. Clinical trials are needed to ascertain the value of antioxidant supplementation in VaD patients.