Contaminants: a dark side of food supplements?

Figures & data

Table 1. Metal contaminants in food supplements. Examples of studies reporting quantifiable levels of arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg)

Type of food supplement	Contaminants^a	Nr^b	Country of sale	Year	Reference
Calcium
Bone, milk, oyster/clam shell, others	As, Cd, Hg	55	Korea	2004	[50]
Natural – oyster shells/Refined	Pb	23	USA	2000	[48]
Organic/inorganic compounds, dolomite, shells	^210Pb	17	Poland	2016	[49]
Diverse^c
Calcium supplements, vitamins	Pb	45^d	USA	2007	[58]
Macro/microelements, vitamins	Hg	33	Poland	2015	[59]
Plant based, MVM, algae	Cd, Pb, Hg	24	Mexico	2007	[60]
Vitamins, minerals, MVM, herb-based	As, Cd, Pb, Hg	30	Croatia	2010	[61]
Mainly plant-based	As, Cd, Pb, Hg	95	USA	2003	[62]
Mainly plant-based, minerals	Hg	40	USA	2005	[63]
Vitamins, MVM, minerals, herb-based	As, Cd, Pb, Hg	33	Lebanon	2013	[55]
Plant-based and algae	As	16	Denmark	2013	[38]
Health clays products	As, Cd, Pb, Hg	27	Netherlands	2013	[64]
Iron supplements	As	15	Brazil/Spain	2017	[47]
Magnesium (organic/inorganic compounds; dolomite)	^210Pb	14	Poland	2017	[51]
Multimineral and MVM supplements	Pb	168	Poland	2018	[57]
Plant-based
Garlic, equinacea, gingko, ginseng, others	As, Cd, Pb	67	USA	2004	[54]
Herbal	Hg	24	Poland	2018	[65]
Prenatal and children supplements	As	10	USA	2014	[66]
Prenatal vitamin supplements	As, Cd, Pb, Hg	51	Canada	2018	[67]
Shark cartilage powder	Hg	16	USA	2014	[68]

MVM: multi-vitamins/minerals.

^a In these studies the metal contaminant was quantified at least in one of the supplements analysed.

^b The term Nr, refers to the number of FS analysed.

^c The designation diverse means that at least three different types of FS were analysed.

^d Pharmaceutical products included in this number.

Table 2. Examples of studies reporting quantifiable levels of mycotoxins in food supplements

Type of food supplement	Contaminants^a	Nr^b	Country of sale	Year	Reference
Plant-based
Green tea	Aflatoxin B1	10	Spain	2016	[79]
Grape	Ochratoxin A	24	Italy^c	2015	[80]
Ginkgo	Aflatoxin B1, aflatoxin B2, T-2	9	Spain, Poland, USA	2015	[81]
Green coffee	Ochratoxin A, ochratoxin B, fumonisin B1, mycophenolic acid	50	USA^c	2013	[74]
Milk thistle	Aflatoxins	79	USA	2012	[78]
Different plants	Deoxynivalenol, trichothecenes, zearalenone, enniatins, alternariol, tentoxin, mycophenolic acid	69	Czech Republic, USA	2015	[76]
	Fumonisins, ochratoxin A	62	Belgium^c	2009	[75]
Diverse (mostly plant-based and Red yeast rice)	Citrinin	7	Croatia	2013	[82]
Red yeast rice	Citrinin	4	Taiwan	2005	[83]
Brewer’s yeast	Ochratoxin A	46	Germany^c	2016	[84]
	Ochratoxin A	51	Germany	2002	[85]

^a In these studies at least one toxin was quantified at least in one of the supplements analysed.

^b The term Nr refers to the number of food supplements analysed.

^c Includes samples obtained online.

Table 3. Examples of studies reporting quantifiable levels of cyanotoxins in food supplements of marine origin

Type of food supplement	Contaminants^a	Nr^b	Country of sale	Year	Reference
Blue green algae	Microcystins, Anatoxin-a, dihydroanatoxin-a, epoxyanatoxin-a, Beta-methylamino-L-alanine	18	Canada^c	2017	[90]
	Microcystins	17	Italy	2012	[91]
Blue green algae and Chlorella	Microcystins	18	Germany	2012	[89]
Shark cartilage	Beta-methylamino-l-alanine	16	USA	2014	[68]

^a In these studies at least one toxin was quantified at least in one of the supplements analysed.

^b The term Nr refers to the number of food supplements analysed.

^c Includes samples obtained online.

Table 4. Examples of studies reporting quantifiable levels of pesticides in food supplements

Type of food supplement	Class of pesticides^a	Nr^b	Country of sale	Year	Reference
Plant-based
Green tea	Insecticides (OPs, CBs, PIs, others) Fungicides Herbicides	10	Spain	2016	[79]
	Acaricides	10	Spain	2014	[97]
Ginseng	Insecticides (OCs, OPs, PIs) Fungicides	23	USA	2016	[98]
Soya	Herbicides	14	Spain	2016	[99]
	Insecticides (OPs, others)	11	Spain	2015	[100]
Ginkgo	Insecticides (OPs, CBs, PIs, others) Fungicides Herbicides	9	Spain, Poland, USA	2015	[81]
Different plants	Insecticides (PIs) Fungicides Herbicides	32	Spain	2015	[101]
Royal jelly	Herbicides	8	Spain	2016	[79]
Oil-based
Fish, seal and vegetable	Insecticides (OCs)	30	Canada^c	2009	[102]
Cod liver	Insecticides (OCs)	15	Italy	2004	[103]
Fish and vegetable	Insecticides (OCs)	21	UK	2004	[104]

OCs: organochlorine insecticides; OPs: organophosphate insecticides; CBs: carbamate insecticides; PIs: pyrethroid insecticides.

^a In these studies, at least one pesticide of each class was quantified at least in one of the supplements analysed.

^b The term Nr refers to the number of FS analysed.

^c Includes samples obtained online.

Table 5. Dioxins, PCBs, and PBDEs residues in food supplements.

Type of food supplement	Type of contaminants^a	Nr^b	Country of sale	Year	Reference
Oil-based
Fish	PCDDs, PCDFs, PCBs	25	Japan	2018	[123]
Vegetable and animal mix		12
Marine mammal		4
Egg yolk		3
Mixtures		2
Fish	PCDDs, PCDFs, PCBs, PBDEs	9	Spain	2011	[124]
Vegetable and fish mix		3
Vegetable		3
Fish	PCBs	11	Canada	2010	[128]
Vegetable		6
Fish	PCBs	5	UK	2002	[125]
Vegetable		1
Fish, vegetable and mix	PCBs	30	Canada^c	2009	[102]
Fish	PCBs, PBDEs	14	UK	2004	[104]
Vegetable and animal mix		3
Vegetable		4
Fish	PCBs	13	USA^c	2013	[127]
	PCBs, PBDEs	1	Norway	2011	[114]
	PCBs, PBDEs	10	USA^c	2010	[126]
	PCBs	3	Spain	2010	[131]
	PCDDs, PCDFs, PCBs, PBDEs	30	Canada^c	2009	[129]
	PCBs, PBDEs	1	USA^c	2009	[112]
	PCBs	16	Czech Republic	2009	[132]
	PCDDs, PCDFs, PCBs, PBDEs	6	Switzerland	2006	[133]
	PCBs, PBDEs	11	Japan	2006	[130]
	PCDDs, PCDFs, PCBs	33	UK	2006	[122]
	PCBs	15	Italy	2004	[103]
	PCBs	38	Australia, Austria, Belgium, Brazil, Canada, France, Japan, NL, NZ, Norway, Spain, UK, USA	1998	[134]
Omega-3	PCDDs, PCDFs, PCBs	9	Spain	2017	[113]
Diverse
Fish oil	PCDDs, PCDFs,	7	Spain	2010	[120]
Vegetable oils	PCBs, PBDEs	5
Vegetable and fish oils mix		2
Mineral mix		1
Fish oil	PCDDs, PCDFs,	15	Ireland	2005	[110]
Fish and vegetable mix oil	PCBs	5
Fish oil and vitamins mix		7
Vitamins		2
Vegetable oils		5
Omega-3 and/or Omega-6		8

PCDDs: polychlorinated dibenzo-p-dioxins; PCDFs: polychlorinated dibenzofurans; PCBs, polychlorinated biphenyls; PBDEs: polybrominated diphenyl ethers.

^a In these studies, dioxins (PCDDs and PCDFs), PCBs, and PBDEs contaminants were quantified at least in one of the food supplements analysed.

^b The term Nr, refers to the number of dietary supplements analysed.

^c Includes samples obtained online.

Table 6. Examples of studies reporting adulteration of food supplements with pharmacological active ingredients

Type of food supplement	Pharmaceutical adulterants	C^a/Nr^b	Country of sale	Year	Reference
Diverse^c (e.g. plant-based, vitamins)	Sibutramine, phenolphthalein	14/20^e	France^d	2010	[143]
	Sibutramine and its analogues, fluoxetine, bisacodyl	62/188^f	South Korea	2014	[144]
	Sibutramine and its analogues, rimonabant, fluoxetine, bisacodyl, phenolphthalein	55/193^f	South Korea	2016	[145]
	Sibutramine, fluoxetine, phenolphthalein	76/370^f	South Korea^d	2018	[146]
	Sibutramine and its analogues, furosemide, bisacodyl, phenolphthalein, thyroid agents	119/447	Singapore	2016	[147]
Plant-based	Sibutramine and its analogues, phenolphthalein	11/22	China	2008	[148]
	Sibutramine and its analogues	23/25	Poland	2011	[149]
	Sibutramine and its analogues, rimonabant, phenolphthalein	24/50	Netherland	2014	[150]
	Sibutramine	26/52	Switzerland^d	2014	[151]
	PDE-5 inhibitors and their analogues	10/64	Czech	2019	[152]
	PDE-5 inhibitors and their analogues	3/11	Italy	2014	[153]
	PDE-5 inhibitors and their analogues	3/26^e	Italy	2015	[154]
	PDE-5 inhibitors, flibanserin, phentolamine, dehydroepiandrosterone, testosterone	92/150	Switzerland^d	2015	[155]
	PDE-5 inhibitors and their analogues, phenolphthalein	11/50	Romania	2017	[156]
	PDE-5 inhibitors and their analogues	74/91	USA	2013	[157]
	PDE-5 inhibitors and their analogues	23/71	Netherland	2013	[158]

^a The term C, refers to the number of food supplements contaminated with pharmacological active ingredients.

^b The term Nr, refers to the number of food supplements analysed.

^c The designation diverse means that at least different three types of food supplements were analysed.

^d Includes samples obtained online.

^eHerbal medicine included in this number.

^fSlimming food products included in this number.

Figure 1. Number of cases reported by RASFF concerning adulteration of food supplements with the most common unauthorised pharmaceutical active substances from 1998 to 2018. Risk seriousness is expressed according to the RASFF classification.

Figure 2. Number of cases reported by RASFF concerning contamination of food supplements with metals from 1998 to 2018. The proportion of reports where the contamination was considered serious is shown in (A) and main country of origin of raw material is shown in (B). Data presented in these graphs was obtained from the RASFF report database. Risk seriousness is expressed according to the RASFF classification.

Table 7. RASFF reports regarding food supplements from 1998 to 2018.

Hazard type	Number of reports	Serious risk^a (%)	Contaminants	Main countries of origin (raw material)
Adulteration^b	251	53(134/251)	See Figure 1
Metals	117	45 (53/117)	See Figure 2(A)	See Figure 2(B)
Mycotoxins	1	100 (1/1)	Citrinin	Slovenia
Natural toxins	7	29 (2/7)	Toxic herbal extracts and Solanum nigrum	India, USA, Netherlands, China, Sweden
Pesticide residues	4	25 (1/4)	Triazophos, germanium, lithium, sulphur, etofenprox, chlorate	Germany, Slovakia, Spain, India
Industrial contaminants	2	0 (0/2)	Melamine, semicarbazide	China, India

Data presented in this table was obtained from the RASFF report database.

^a Risk seriousness according to the RASFF classification.

^b The types of adulteration considered in this table are further specified in Figure 1.

Kim M. Mercury, cadmium and arsenic contents of calcium dietary supplements. Food Addit Contam. 2004;21(8):763–767.

 PubMed Web of Science ®Google Scholar

Ross EA, Szabo NJ, Tebbett IR. Lead content of calcium supplements. JAMA. 2000;284(11):1425–1429.

 PubMed Web of Science ®Google Scholar

Strumińska-Parulska DI. Radiolead (210)Pb and (210)Po/(210)Pb activity ratios in calcium supplements and the assessment of their possible dose to consumers. J Environ Sci Health A Tox Hazard Subst Environ Eng. 2016;51(10):851–854.

 PubMed Web of Science ®Google Scholar

Kauffman JF, Westenberger BJ, Robertson JD, et al. Lead in pharmaceutical products and dietary supplements. Regul Toxicol Pharmacol. 2007;48(2):128–134.

 PubMed Web of Science ®Google Scholar

Kowalski A, Frankowski M. Levels and potential health risks of mercury in prescription, non-prescription medicines and dietary supplements in Poland. Regul Toxicol Pharmacol. 2015;73(1):396–400.

 PubMed Web of Science ®Google Scholar

García-Rico L, Leyva-Perez J, Jara-Marini ME. Content and daily intake of copper, zinc, lead, cadmium, and mercury from dietary supplements in Mexico. Food Chem Toxicol. 2007;45(9):1599–1605.

 PubMed Web of Science ®Google Scholar

Tumir H, Bošnir J, Vedrina-Dragojević I, et al. Monitoring of metal and metalloid content in dietary supplements on the Croatian market. Food Control. 2010;21(6):885–889.

 Web of Science ®Google Scholar

Dolan SP, Nortrup DA, Bolger PM, et al. Analysis of dietary supplements for arsenic, cadmium, mercury, and lead using inductively coupled plasma mass spectrometry. J Agric Food Chem. 2003;51(5):1307–1312.

 PubMed Web of Science ®Google Scholar

Levine KE, Levine MA, Weber FX, et al. Determination of mercury in an assortment of dietary supplements using an inexpensive combustion atomic absorption spectrometry technique. J Autom Methods Manag Chem. 2005;2005:211–216.

 PubMedGoogle Scholar

Korfali SI, Hawi T, Mroueh M. Evaluation of heavy metals content in dietary supplements in Lebanon. Chem Cent J. 2013;7(1):10.

 PubMedGoogle Scholar

Hedegaard RV, Rokkjær I, Sloth JJ. Total and inorganic arsenic in dietary supplements based on herbs, other botanicals and algae–a possible contributor to inorganic arsenic exposure. Anal Bioanal Chem. 2013;405(13):4429–4435.

 PubMed Web of Science ®Google Scholar

Reeuwijk NM, Klerx WNM, Kooijman M, et al. Levels of lead, arsenic, mercury and cadmium in clays for oral use on the Dutch market and estimation of associated risks. Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2013;30(9):1535–1545.

 PubMed Web of Science ®Google Scholar

Araujo-Barbosa U, Peña-Vazquez E, Barciela-Alonso MC, et al. Simultaneous determination and speciation analysis of arsenic and chromium in iron supplements used for iron-deficiency anemia treatment by HPLC-ICP-MS. Talanta. 2017;170:523–529.

 PubMed Web of Science ®Google Scholar

Strumińska-Parulska DI. 210Pb in magnesium dietary supplements. Isot Environ Health Stud. 2017;53(2):111–115.

 PubMed Web of Science ®Google Scholar

Poniedziałek B, Niedzielski P, Kozak L, et al. Monitoring of essential and toxic elements in multi-ingredient food supplements produced in European Union. J Consum Prot Food Saf. 2018;13(1):41–48.

 Web of Science ®Google Scholar

Raman P, Patino LC, Nair MG. Evaluation of metal and microbial contamination in botanical supplements. J Agric Food Chem. 2004;52(26):7822–7827.

 PubMed Web of Science ®Google Scholar

Brodziak-Dopierała B, Fischer A, Szczelina W, et al. The content of mercury in herbal dietary supplements. Biol Trace Elem Res. 2018;185(1):236–243.

 PubMed Web of Science ®Google Scholar

Wolle MM, Rahman GMM, Kingston HM, et al. Speciation analysis of arsenic in prenatal and children’s dietary supplements using microwave-enhanced extraction and ion chromatography-inductively coupled plasma mass spectrometry. Anal Chim Acta. 2014;818:23–31.

 PubMed Web of Science ®Google Scholar

Schwalfenberg G, Rodushkin I, Genuis SJ. Heavy metal contamination of prenatal vitamins. Toxicol Rep. 2018;5:390–395.

 PubMed Web of Science ®Google Scholar

Mondo K, Broc Glover W, Murch SJ, et al. Environmental neurotoxins β-N-methylamino-l-alanine (BMAA) and mercury in shark cartilage dietary supplements. Food Chem Toxicol. 2014;70:26–32.

 PubMed Web of Science ®Google Scholar

Martínez-Domínguez G, Romero-González R, Frenich AG. Multi-class methodology to determine pesticides and mycotoxins in green tea and royal jelly supplements by liquid chromatography coupled to Orbitrap high resolution mass spectrometry. Food Chem. 2016;197:907–915.

 PubMed Web of Science ®Google Scholar

Solfrizzo M, Piemontese L, Gambacorta L, et al. Food coloring agents and plant food supplements derived from Vitis vinifera: a new source of human exposure to ochratoxin A. J Agric Food Chem. 2015;63(13):3609–3614.

 PubMed Web of Science ®Google Scholar

Martínez-Domínguez G, Romero-González R, Garrido Frenich A. Determination of toxic substances, pesticides and mycotoxins, in ginkgo biloba nutraceutical products by liquid chromatography Orbitrap-mass spectrometry. Microchem J. 2015;118:124–130.

 Web of Science ®Google Scholar

Vaclavik L, Vaclavikova M, Begley TH, et al. Determination of multiple mycotoxins in dietary supplements containing green coffee bean extracts using ultrahigh-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS). J Agric Food Chem. 2013;61(20):4822–4830.

 PubMed Web of Science ®Google Scholar

Tournas VH, Sapp C, Trucksess MW. Occurrence of aflatoxins in milk thistle herbal supplements. Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2012;29(6):994–999.

 PubMed Web of Science ®Google Scholar

Veprikova Z, Zachariasova M, Dzuman Z, et al. Mycotoxins in plant-based dietary supplements: hidden health risk for consumers. J Agric Food Chem. 2015;63(29):6633–6643.

 PubMed Web of Science ®Google Scholar

Diana Di Mavungu J, Monbaliu S, Scippo ML, et al. LC-MS/MS multi-analyte method for mycotoxin determination in food supplements. Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2009;26(6):885–895.

 PubMed Web of Science ®Google Scholar

Nigović B, Sertić M, Mornar A. Simultaneous determination of lovastatin and citrinin in red yeast rice supplements by micellar electrokinetic capillary chromatography. Food Chem. 2013;138(1):531–538.

 PubMed Web of Science ®Google Scholar

Liu BH, Wu TS, Su MC, et al. Evaluation of citrinin occurrence and cytotoxicity in Monascus fermentation products. J Agric Food Chem. 2005;53(1):170–175.

 PubMed Web of Science ®Google Scholar

Gottschalk C, Biermaier B, Gross M, et al. Ochratoxin A in brewer’s yeast used as food supplement. Mycotoxin Res. 2016;32(1):1–5.

 PubMed Web of Science ®Google Scholar

Gareis M. Ochratoxin A in brewer’s yeast used as nutrient supplement. Mycotoxin Res. 2002;18:128–131.

 PubMedGoogle Scholar

Roy-Lachapelle A, Solliec M, Bouchard MF, et al. Detection of cyanotoxins in algae dietary supplements. Toxins (Basel). 2017;9(3):76.

 Web of Science ®Google Scholar

Vichi S, Lavorini P, Funari E, et al. Contamination by microcystis and microcystins of blue-green algae food supplements (BGAS) on the Italian market and possible risk for the exposed population. Food Chem Toxicol. 2012;50(12):4493–4499.

 PubMed Web of Science ®Google Scholar

Heussner AH, Mazija L, Fastner J, et al. Toxin content and cytotoxicity of algal dietary supplements. Toxicol Appl Pharmacol. 2012;265(2):263–271.

 PubMed Web of Science ®Google Scholar

Martínez-Domínguez G, Plaza-Bolaños P, Romero-González R, et al. Multiresidue method for the fast determination of pesticides in nutraceutical products (Camellia sinensis) by GC coupled to triple quadrupole MS. J Sep Sci. 2014;37(6):665–674.

 PubMed Web of Science ®Google Scholar

Chen Y, Lopez S, Hayward DG, et al. Determination of multiresidue pesticides in botanical dietary supplements using gas chromatography–triple-quadrupole mass spectrometry (GC-MS/MS). J Agric Food Chem. 2016;64(31):6125–6132.

 PubMed Web of Science ®Google Scholar

Domingos Alves R, Romero-González R, López-Ruiz R, et al. Fast determination of four polar contaminants in soy nutraceutical products by liquid chromatography coupled to tandem mass spectrometry. Anal Bioanal Chem. 2016;408(28):8089–8098.

 PubMed Web of Science ®Google Scholar

Páleníková A, Martínez-Domínguez G, Arrebola FJ, et al. Multifamily determination of pesticide residues in soya-based nutraceutical products by GC/MS–MS. Food Chem. 2015;173:796–807.

 PubMed Web of Science ®Google Scholar

Páleníková A, Martínez-Domínguez G, Arrebola FJ, et al. Occurrence of pesticide residues and transformation products in different types of dietary supplements. Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2015;32(6):849–856.

 PubMed Web of Science ®Google Scholar

Rawn DFK, Breakell K, Verigin V, et al. Persistent organic pollutants in fish oil supplements on the Canadian market: polychlorinated biphenyls and organochlorine insecticides. J Food Sci. 2009;74(1):T14–T19.

 PubMed Web of Science ®Google Scholar

Storelli MM, Storelli A, Marcotrigiano GO. Polychlorinated biphenyls, hexachlorobenzene, hexachlorocyclohexane isomers, and pesticide organochlorine residues in cod-liver oil dietary supplements. J Food Prot. 2004;67(8):1787–1791.

 PubMed Web of Science ®Google Scholar

Jacobs MN, Covaci A, Gheorghe A, et al. Time trend investigation of PCBs, PBDEs, and organochlorine pesticides in selected n −3 polyunsaturated fatty acid rich dietary fish oil and vegetable oil supplements; nutritional relevance for human essential n −3 fatty acid requirements. J Agric Food Chem. 2004;52(6):1780–1788.

 PubMed Web of Science ®Google Scholar

Tsutsumi T, Takatsuki S, Teshima R, et al. Dioxin concentrations in dietary supplements containing animal oil on the Japanese market between 2007 and 2014. Chemosphere. 2018;191:514–519.

 PubMed Web of Science ®Google Scholar

Ortiz X, Guerra P, Díaz-Ferrero J, et al. Diastereoisomer- and enantiomer-specific determination of hexabromocyclododecane in fish oil for food and feed. Chemosphere. 2011;82(5):739–744.

 PubMed Web of Science ®Google Scholar

Bourdon JA, Bazinet TM, Arnason TT, et al. Polychlorinated biphenyls (PCBs) contamination and aryl hydrocarbon receptor (AhR) agonist activity of Omega-3 polyunsaturated fatty acid supplements: implications for daily intake of dioxins and PCBs. Food Chem Toxicol. 2010;48(11):3093–3097.

 PubMed Web of Science ®Google Scholar

Jacobs MN, Covaci A, Schepens P. Investigation of selected persistent organic pollutants in farmed Atlantic Salmon (Salmo salar), salmon aquaculture feed, and fish oil components of the feed. Environ Sci Technol. 2002;36(13):2797–2805.

 PubMed Web of Science ®Google Scholar

Ashley JTF, Ward JS, Anderson CS, et al. Children’s daily exposure to polychlorinated biphenyls from dietary supplements containing fish oils. Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2013;30(3):506–514.

 PubMed Web of Science ®Google Scholar

Montaño M, Zimmer KE, Dahl E, et al. Effects of mixtures of persistent organic pollutants (POPs) derived from cod liver oil on H295R steroidogenesis. Food Chem Toxicol. 2011;49(9):2328–2335.

 PubMed Web of Science ®Google Scholar

Ashley JTF, Ward JS, Schafer MW, et al. Evaluating daily exposure to polychlorinated biphenyls and polybrominated diphenyl ethers in fish oil supplements. Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2010;27(8):1177–1185.

 PubMed Web of Science ®Google Scholar

Nevado JJB, Martín-Doimeadiós RCR, Guzmán Bernardo FJG, et al. Multiresidue determination of organochlorines in fish oil by GC-MS: a new strategy in the sample preparation. Talanta. 2010;81(3):887–893.

 PubMed Web of Science ®Google Scholar

Rawn DFK, Breakell K, Verigin V, et al. Persistent organic pollutants in fish oil supplements on the Canadian market: polychlorinated dibenzo-p-dioxins, dibenzofurans, and polybrominated diphenyl ethers. J Food Sci. 2009;74(4):T31–T36.

 PubMed Web of Science ®Google Scholar

Hoh E, Lehotay SJ, Mastovska K, et al. Capabilities of direct sample introduction–comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry to analyze organic chemicals of interest in fish oils. Environ Sci Technol. 2009;43(9):3240–3247.

 PubMed Web of Science ®Google Scholar

Smutna M, Kruzikova K, Marsalek P, et al. Fish oil and cod liver as safe and healthy food supplements. Neuro Endocrinol Lett. 2009;30:156–162.

 PubMed Web of Science ®Google Scholar

Zennegg M, Schmid P. PCDD/F, PCB, dioxin-like PCB, and PBDE in fish oil used as dietary supplement in Switzerland. Organohalogen Compd. 2006;68:1967–1970.

 Google Scholar

Akutsu K, Tanaka Y, Hayakawa K. Occurrence of polybrominated diphenyl ethers and polychlorinated biphenyls in shark liver oil supplements. Food Addit Contam. 2006;23(12):1323–1329.

 PubMed Web of Science ®Google Scholar

Fernandes AR, Rose M, White S, et al. Dioxins and polychlorinated biphenyls (PCBs) in fish oil dietary supplements: occurrence and human exposure in the UK. Food Addit Contam. 2006;23(9):939–947.

 PubMed Web of Science ®Google Scholar

Jacobs MN, Santillo D, Johnston PA, et al. Organochlorine residues in fish oil dietary supplements: comparison with industrial grade oils. Chemosphere. 1998;37(9–12):1709–1721.

 PubMed Web of Science ®Google Scholar

García-Bermejo Á, Herrero L, González MJ, et al. Occurrence and estimated dietary intake of PCBs and PCDD/Fs in functional foods enriched with Omega-3 from Spain. J Agric Food Chem. 2017;65(16):3396–3405.

 PubMed Web of Science ®Google Scholar

Martí M, Ortiz X, Gasser M, et al. Persistent organic pollutants (PCDD/Fs, dioxin-like PCBs, marker PCBs, and PBDEs) in health supplements on the Spanish market. Chemosphere. 2010;78(10):1256–1262.

 PubMed Web of Science ®Google Scholar

FSAI (Food Safety Authority of Ireland). Investigation into levels of dioxins, furans, PCBs and PBDEs in food supplements, offal and milk; 2005.

 Google Scholar

Vaysse J, Balayssac S, Gilard V, et al. Analysis of adulterated herbal medicines and dietary supplements marketed for weight loss by DOSY 1 H-NMR. Food Addit Contam A. 2010;27(7):903–916.

 Web of Science ®Google Scholar

Kim HJ, Lee JH, Park HJ, et al. Monitoring of 29 weight loss compounds in foods and dietary supplements by LC-MS/MS. Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2014;31(5):777–783.

 PubMed Web of Science ®Google Scholar

Kim JY, Park HJ, Kim JW, et al. Development and validation of UPLC and LC-MS/MS methods for the simultaneous determination of anti-obesity drugs in foods and dietary supplements. Arch Pharm Res. 2016;39(1):103–114.

 PubMed Web of Science ®Google Scholar

Yun J, Choi J, Jo CH, et al. Detection of synthetic anti-obesity drugs, designer analogues and weight- loss ingredients as adulterants in slimming foods from 2015 to 2017. J Chromatogr Sep Tech. 2018;09:1–6.

 Google Scholar

Zeng Y, Xu Y, Kee C-L, et al. Analysis of 40 weight loss compounds adulterated in health supplements by liquid chromatography quadrupole linear ion trap mass spectrometry. Drug Test Analysis. 2016;8(3–4):351–356.

 PubMed Web of Science ®Google Scholar

Wang J, Chen B, Yao S. Analysis of six synthetic adulterants in herbal weight-reducing dietary supplements by LC electrospray ionization-MS. Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2008;25(7):822–830.

 PubMed Web of Science ®Google Scholar

Stypułkowska K, Błażewicz A, Maurin J, et al. X-ray powder diffractometry and liquid chromatography studies of sibutramine and its analogues content in herbal dietary supplements. J Pharm Biomed Anal. 2011;56(5):969–975.

 PubMed Web of Science ®Google Scholar

Reeuwijk NM, Venhuis BJ, de Kaste D, et al. Active pharmaceutical ingredients detected in herbal food supplements for weight loss sampled on the Dutch market. Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2014;31(11):1783–1793.

 PubMed Web of Science ®Google Scholar

Mathon C, Ankli A, Reich E, et al. Screening and determination of sibutramine in adulterated herbal slimming supplements by HPTLC-UV densitometry. Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2014;31(1):15–20.

 PubMed Web of Science ®Google Scholar

Jiru M, Stranska-Zachariasova M, Dzuman Z, et al. Analysis of phosphodiesterase type 5 inhibitors as possible adulterants of botanical-based dietary supplements: extensive survey of preparations available at the Czech market. J Pharm Biomed Anal. 2019;164:713–724.

 PubMed Web of Science ®Google Scholar

Damiano F, Silva C, Gregori A, et al. Analysis of illicit dietary supplements sold in the Italian market: identification of a sildenafil thioderivative as adulterant using UPLC–TOF/MS and GC/MS. Sci Justice. 2014;54(3):228–237.

 PubMed Web of Science ®Google Scholar

Bortolini C, Pivato A, Bogialli S, et al. ‘One-shot’ analysis of PDE-5 inhibitors and analogues in counterfeit herbal natural products using an LC-DAD-QTOF system. Anal Bioanal Chem. 2015;407(20):6207–6216.

 PubMed Web of Science ®Google Scholar

Gilard V, Balayssac S, Tinaugus A, et al. Detection, identification and quantification by 1H NMR of adulterants in 150 herbal dietary supplements marketed for improving sexual performance. J Pharm Biomed Anal. 2015;102:476–493.

 PubMed Web of Science ®Google Scholar

Mateescu C, Popescu AM, Radu GL, et al. Spectroscopic and spectrometric methods used for the screening of certain herbal food supplements suspected of adulteration. Adv Pharm Bull. 2017;7(2):251–259.

 PubMed Web of Science ®Google Scholar

Campbell N, Clark JP, Stecher VJ, et al. Adulteration of purported herbal and natural sexual performance enhancement dietary supplements with synthetic phosphodiesterase Type 5 inhibitors. J Sex Med. 2013;10(7):1842–1849.

 PubMed Web of Science ®Google Scholar

Reeuwijk NM, Venhuis BJ, de Kaste D, et al. Sildenafil and analogous phosphodiesterase type 5 (PDE-5) inhibitors in herbal food supplements sampled on the Dutch market. Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2013;30(12):2027–2034.

 PubMed Web of Science ®Google Scholar