Long-term supplementation with B vitamins does not change plasma neopterin concentrations in demented patients

Abstract

Inflammation and immune system activation seem to play an important role in the development and progression of dementia. Also concentrations of immune activation marker neopterin are increased in serum and cerebrospinal fluid of some patients with dementia, and a significant relationship is found between concentrations of neopterin and homocysteine. B vitamin supplementation is able to rapidly slow-down homocysteine formation in patients. However, no change of neopterin was found within one month of such therapy. In this study, serum concentrations of neopterin and homocysteine were investigated in 58 patients with Alzheimer's disease (n=30), vascular dementia (n=12) and mild cognitive impairment (n=16) during 1 -3 months of supplementation with B vitamins (Beneuran composition®) with monthly increasing dose (1-6 tablets a day). No change of neopterin concentrations was observed In the patients groups throughout the whole study period (all p >0.05). As was reported earlier, a rapid decline of homocysteine concentrations was achieved already within the first month of supplementation (p <0.01), however, no further change of homocysteine was observed later on despite accelerated dose of vitamin supplements. B vitamin supplementation did not influence neopterin concentrations, and also the longer period of supplementation had no effect. The question remains, if solely the lowering of homocysteine concentrations by folate supplementation could have any beneficial effect to modulate the course of dementia when the immunopathogenetic mechanisms are not influenced.