Determination of the Content of Mercury in Vitamin and Mineral Dietary Supplements

Abstract

Dietary supplements are more and more often used to increase daily intake of essential vitamins and minerals. These preparations are classified as special category of foods and are subject to food law, not pharmaceutical regulations. As a result the requirements to dietary supplements are much less restrictive than to medications. Also simple and inexpensive procedure of registration causes that the number of dietary supplements is widely spread every year. On every manufacturing phases of dietary supplements, there is a risk of contamination. One of the pollutions might be mercury which is classified as heavy metal. Its inorganic compounds damage kidneys and liver and methylmercury is easily absorbed from gastrointestinal system. Methylmercury is distributed in all tissues, also in nervous system. The aim of study was to determine the level of mercury in multivitamins and multiminerals preparations and to analyze the results. The study included 22 dietary supplements containing vitamins and minerals available on Polish market. Mercury was analyzed with atomic absorption spectrometry using AMA 254. The concentrations of Hg was 0.22–5.85 µg/kg (the average content was 2.40 µg/kg). The highest average mercury content was 4.51 µg/kg, whereas the lowest one was 0.31 µg/kg. The results was also analyzed in individual groups depending on main component and indication for use as well as pharmaceutical formulation. Also according to manufacturer’s recommendation, the dose of mercury taken with a single medicine was estimated for time of a day, a week, a month, 3 months and also a year. The findings were compared to limits defined in regulations of European Union and PTWI set by JECFA to assess the health risk. The results presented in this study proved that the amount of mercury in tested dietary supplements is much lower than the value of valid regulations. Analyzed supplements as long as they are used with the recommendation of manufacturer, do not pose a threat to human health.