Biomarkers of oxidative stress and redox status in a short-term low-dosed multivitamin and mineral supplementation study in two human age groups.

A 60-day intervention study was conducted in which the participants took a low dose of a multivitamin and mineral supplement. The study consists of a final number of 66 volunteers (30 males and 36 females), divided into two age groups of 30-35 and 60-65 years. For 30 days they took a multivitamin and mineral supplement with 1× the recommended daily intake (RDI) followed by another 30 days with 2× the RDI. The aim of the study was to monitor oxidative stress and redox status of both young and old age groups. In serum, the expected increase of the water-soluble vitamins folate and vitamin B12 was observed with a concomitant decrease in homocysteine. Serum biomarkers of oxidative stress, the reactive oxygen metabolites, of the antioxidant status, the biological antioxidant potential did not change. However, the total thiol levels in serum, biomarker of the redox status, decreased significant, only in both groups of elderly after 60 days. In erythrocytes, there was a change in the glutathione metabolism as observed by an increase in glutathione reductase and to a lower extend in glutathione peroxidase, indicating an increase in oxidative stress in all groups. It is concluded that a low-dosed multivitamin and -mineral supplementation have different effects on the redox status in young versus old. It remained to explain why a low dose of a multivitamin and -mineral supplement cause increased oxidative stress.