Tissue toxicity in a low-dosed multivitamin and mineral supplementation study in human volunteers

Abstract

The use of multi-vitamin and mineral supplements is increasing. Especially the elderly population could benefit from an increased vitamin status. In a number of studies, however, benefits are questioned and even adverse effects are reported. Aim: In the present study the possible adverse effects of a low-dose of multivitamin- and mineral supplement is investigated by means of a biomarker approach of tissue toxicity of liver and kidney. Methods: A supplementation study was performed with human volunteers in which a low dose of vitamins and minerals of 1x the recommended daily intake (RDI) was given for one month and 2x the RDI for another month. The participants were divided in a male and a female group and each group was divided in two age groups of 30–35 and 60–65 years. The possible kidney and liver toxicity was monitored by the serum measurements of creatinine, urea and uric acid for kidney toxicity and the enzymes alanine and aspartate aminotransferase albumin, total cholesterol and bilirubin for liver toxicity. Results: Liver toxicity was observed in both younger and older female groups by a statistically significant increase of two liver enzymes, alanine aminotransferase and aspartate aminotransferase. The increase of enzyme activities, however, did not reach pathological levels. Kidney toxicity was not observed in any of the groups. Apparently, women are more sensitive to changes in vitamin or mineral status which can affect liver enzymes. This finding supports the recommendation to test supplements before marketing.