‎ Investigation on Presence Determination of Metal Contaminants in Dietary ‎Supplements

Introduction: Dietary supplements (DS) are preparations intended to deliver nutrients that may not be consumed in sufficient quantities in the diet. They improve health and are popular in different populations and age groups. Nevertheless, this popularity and most of the time using them without health professional advice expose consumers to the ingestion of different harmful contaminants that may lead to deleterious effects on human health. Methods: A comprehensive literature search was performed during years 1994-2020. Many medical and scientific literatures on the authors opinion regarding presence of metal contaminants in DS and the analytical methods were collected. Results: In different categories of DS metal contamination might occur as a consequence of a single factor or as a combination of sources. For determination purposes many analytical techniques have been developed. However, selection of a technique depends on the elements, concentration in the digested sample, detection limits, interference, accuracy, precision, linear range, and etc. Conclusion: Various authors emphasized on applying proper quality control in different steps of dietary supplements production and quality assurance of all manufacturing phases to ensures that packaging materials and final products conform to the established criteria’s of the country. It is hoped besides proper quality control and use of reference materials as a critical step , the knowledge of consumers toward the use of DS be increased by holding health care communication programs and these products consumed under medical advice.