Clinical and analytical toxicology of dietary supplements: a case study and a review of the literature.
ABSTRACT The use of dietary supplements has grown dramatically in the last decade. A large number of dietary and herbal supplements escape regulatory and quality control; components of these preparations are poisonous and may contain, among other toxins, heavy metals. Uncontrolled use of dietary and herbal supplements by special populations, such as the military, may therefore pose a health risk. Clinical symptoms are not always properly attributed to dietary supplements; patients often do not mention supplement use to their health care provider. Therefore, a health risk estimate is hard to make on either the individual or the population level. The literature on this issue was reviewed and discussed in the light of a representative clinical-chemical case study. This case study was performed on a host of preparations that were used by one single individual in the military. Both essential (chromium, copper, zinc, and iron) and poisonous (arsenic, lead, and nickel) trace elements were determined using inductively coupled plasma combined with optical emission spectrometry (ICP-OES) or with mass spectrometry (ICP-MS). Arsenic and lead were detected at exposure levels associated with health risks. These health risks were detected predominantly in hormone-containing supplements and the herbs and botanicals used for performance enhancement. To the extent that this is a representative sample, there is an underestimation of supplement use and supplement risk in the US military, if not in the general population. Since clinical symptoms may be attributed to other causes and, unless patients are specifically asked, health care providers may not be aware of their patients' use of dietary supplements, a strong support of laboratory diagnostics, such as a toxicological screening of blood or urine, is required. In addition, screening of the preparations themselves may be advised.
- SourceAvailable from: Laura Sánchez-Hernández[Show abstract] [Hide abstract]
ABSTRACT: This paper reports the application of a capillary electrophoresis–electrospray ionisation-tandem mass spectrometry methodology for the unequivocal identification and the quantitative determination of the two enantiomers of the non-protein amino acid carnitine (l- and d-Carn) in 22 dietary food supplements, including drinks, biscuits, capsules and tablets. MS/MS experiments were optimised to achieve the high sensitivity and selectivity required for food analysis. A comparison of the slopes obtained by the external standard and the standard additions calibration methods indicated the absence of matrix interferences in these food samples. Good precision (RSDs ranged from 2.3% to 4.3% for migration times, and from 2.1% to 10.5% for corrected peak areas) and acceptable accuracy established by means of recovery studies (from 85% to 102%) were obtained. The limit of detection was about 10 ng/mL (S/N = 3) enabling the determination of enantiomeric impurities (d-Carn) up to 0.025% of Carn in foods. This chiral method illustrated is suitable for routine qualitative and quantitative analyses of Carn in foods. The results showed contents for l-Carn comprised from 47% to 115% with respect to the labelled content of l-Carn. Percentages obtained for the d-enantiomer ranged from 0.4% to 5.9%, except for one of the samples analysed, that contained the racemate (49.3% d-Carn). The use of the racemate is not allowed by legislation, which corroborated the high potential of the developed method in the control of the quality and safety of foods containing Carn.Food Chemistry 06/2010; DOI:10.1016/j.foodchem.2009.11.004 · 3.26 Impact Factor
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ABSTRACT: It is estimated that about 70-80% of the world's population relies on non-conventional medicine, mainly of herbal origin. However, owing to the nature and sources of herbal medicines, they are sometimes contaminated with toxic heavy metals such as lead, arsenic, mercury and cadmium, which impose serious health risks to consumers. It is critical to analyse source materials for heavy metals in order to ensure that their concentrations meet the related standards or regulations limiting their concentrations in herbal medicines. In this review, different analytical methods for analysis of heavy metals in herbal medicines are discussed. To provide a comprehensive review of the current state of the art in analytical methods used to detect heavy metals in herbal medicines. We systematically searched and reviewed the research articles regarding analytical methods for heavy metals in herbal medicine from various databases, such as Medline/PubMed, ScienceDirect, SciFinder, Google Scholar, EBSCO, Gale InfoTrac, Ingenta, Ovid, ProQuest and ISI Web of Knowledge. In this review, we discuss in detail several commonly used and sensitive analytical techniques, including atomic absorption spectrometry, inductively coupled plasma optical emission spectrometry or mass spectrometry, X-ray fluorescence spectrometry, high-performance liquid chromatography, differential pulse polarography, neutron activation analysis and anodic stripping voltammetry. We also provide some application examples of these analytical techniques for heavy metals in herbal medicines.Phytochemical Analysis 05/2011; 22(3):189-98. DOI:10.1002/pca.1287 · 2.45 Impact Factor
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ABSTRACT: Iron is involved in many critical physiologic processes within the hair follicle, suggesting that iron deficiency could disrupt hair synthesis. However, studies of iron as a cause of hair loss have produced conflicting results. Some of the discrepancies may relate to limitations of assays for iron deficiency. This commentary discusses the sensitivity and specificity of available tests for iron deficiency and presents practical guidelines for testing and supplementation.Journal of the American Academy of Dermatology 09/2010; 63(6):1077-82. DOI:10.1016/j.jaad.2009.09.054 · 5.00 Impact Factor