Bioavailability of magnesium and zinc from food supplements

This bachelor's thesis deals with the analysis of dietary supplements containing magnesium and zinc. The analysis examined the content of active substance and solubility in simulated gastric acid. The method used to analyze the active substance content was inductively coupled plasma optical emission spectrometry. This method was also used to determine the degree of solubility of the active substances. A total of thirteen different samples of dietary supplements were examined, all of which contained magnesium as the active ingredient and four of these samples additionally contained zinc. All samples contained the declared amount of magnesium. The zinc amount in food supplements was in accordance with the content stated on the label. In some samples the amount of zinc was determined to be lower, but the deviation from the declared amount did not exceed 14 %. Solubility tests have shown that some products do not contain a suitable type of coating to protect the active substance, which may cause a deterioration in bioavailability