Monitoring of essential and toxic elements in multi-ingredient food supplements produced in European Union

Abstract

The market of food supplements (FS) in European Union (EU) is on the rise. The present study investigated the content of essential (Ca, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Zn) and toxic elements (Cd, Cr(VI), Ni and Pb) in 168 FS produced in the EU and designed to support various health aspects (nutrition, neurological function, reproduction, weight loss, cosmetic appearance). The majority of FS did not exceed a dissolution time of 60 min in hydrochloric acid (89.8%) and phosphate buffer (85.7%). Cd and Cr(VI) were not detected in any FS, Ni and Pb were present sporadically (in 10.1 and 6.5%, respectively) at mean concentrations of 0.06 and 0.07 mg/single unit dose, respectively. All FS containing detectable Pb levels had exceeded a maximum allowance level (3.0 mg kg -1 ) set by the European Commission. Generally, the determined concentrations of essential elements fall greatly below recommended safety upper limits, except Fe in selected FS (mainly for pregnant women). Compared to the value declared on the product label, the majority of tested FS displayed mineral content below the accepted margin (70-130%). In general, the majority of the studied FS can be considered safe although discrepancies between declared and determined mineral content are worrisome. These findings are important in view of FS consumer safety.

Essential and toxic elements in commercial microalgal food supplements

“…Considering the biological activities of Spirulina and Chlorella food supplements, now evidenced also on a clinical level, it is expected that the market for these products will continue to develop. Thus, it is imperative to ensure that the quality of the final product is high and safe for consumers through, e.g., implementation of a food safety management system according to ISO 22000, efficient enforcement of various food regulations, systematic monitoring of contaminant levels, and credibility of information declared on the product label (Fernández-Segovia et al 2014;Poniedziałek et al 2018). The present study is a comprehensive assessment of Spirulina and Chlorella food supplements registered for trade in the EU as regards levels of essential and (potentially) toxic elements.…”

“…An effort is required to eliminate microalgal biomass contaminated significantly with Pb to decrease exposure and ensure consumer safety. One should, however, note that selected multi-ingredient food supplements that contain a mixture of vitamins and minerals have been reported to contain even greater Pb content (Poniedziałek et al 2018). The potential monitoring enforcement should therefore encompass not only microalgal-based formulations but all food supplements.…”

“…Recent studies have shown that various food supplements such as multi-ingredient formulas can reveal high discrepancies between the factual nutritional value and that which is declared on the product label (Brandon et al 2014;Niedzielski et al 2016;Poniedziałek et al 2018). Large-scale cultivation of microalgae for food production that most often employs raceway pond systems is prone to various environmental conditions, mitigation of which may be challenging.…”

“…To determine Cr (VI), the colorimetric method with 1,5diphenylcarbazide was applied (Poniedziałek et al 2018). For 2 mL of the sample extracted by 1 M phosphoric acid, several drops of 0.5% (m/m) solution of diphenylcarbazide in acetone were added.…”

“…These minerals were selected because unlike Se, Na, P, Zn, Ce, Mo, and Co, these minerals were listed on the labels of the majority of the studied products. Seventy to 130% of declared value was considered as an acceptable margin (Niedzielski et al 2016;Poniedziałek et al 2018). In the case of As, the provisional Tolerable Weekly Intake (PTWI) established at a level of 15 μg kg −1 body weight (bw) of total As previously by the Joint FAO/WHO Expert Committee on Food Additives (JECFA 2012) has been disapproved by EFSA as inappropriate as adverse effects have been reported for exposures at lower levels of As.…”