Vitamin D: can fish food-based solutions be used for reduction of vitamin D deficiency in Poland?

OBJECTIVE: The multitude of diseases promoted by vitamin D deficiency makes providing the human organism with a constant and sufficiently high supply of this compound a high priority. The aim of this study was to verify the extent to which fish present in the Polish diet can satisfy the body's requirement for this compound. The obtained data would help to evaluate whether a diet rich in fish may be a solution for vitamin D deficiency. METHODS: Cholecalciferol and ergocalciferol in muscle tissues of fish species popular in the Polish market were determined by means of high-performance liquid chromatography. Based on these updated data, and on data regarding fish consumption, it was possible to assess the level of vitamin D intake provided by fish consumption. RESULTS: This study proved that some of the investigated species of fish are a good source of vitamin D3. Among wild fish, Baltic salmon and herring contained the highest amount of cholecalciferol. Surprisingly, the highest content of this compound was observed in lean tilapia, farmed in China. Ergocalciferol also was found in the studied fish samples. CONCLUSION: Analysis of vitamin D content in various fish species indicated that the disproportion between requirement and supply seems too vast to enable eradication of vitamin D deficiency by fish food-based solutions. Still, increasing fish consumption or changing consumption patterns could be beneficial and result in noticeable improvements in vitamin D status.

The occurrence of organic contaminants in European eel (Anguilla anguilla) in Poland: an environmental quality assessment.

The objective of the present study was to provide information on the levels of pollutants in the tissues of eels caught in Polish waters. The contaminants included in the study are those which have not yet been widely studied in eel stocks, but which arouse concern in relation to the environment. An overview of the pollutant levels in eels caught in other European waters was also conducted. The results are evaluated in terms of environmental quality and consumer health. The mean concentrations of ΣPBDEs and ΣHBCDs in muscles of eels sampled in Polish waters were between 1 and 2 ng g(-1) ww. The mean TBT concentrations were between 2 and 4 ng g(-1)ww with the exception of samples from the Szczecin Lagoon, in which the mean TBT concentration was about tenfold higher.

Persistent organic pollutants in sediment from the southern Baltic: risk assessment.

The concentrations of organochlorine pesticides, PCBs, and PCDD/Fs were measured in sediment samples collected from the Gulf of Gdansk, the Gdansk Deep, the Vistula Lagoon and the off-shore waters in the southern Baltic Sea. The determinations were conducted in the fraction <63 µm. The highest levels of pollutants were found in sediments from the Gulf of Gdansk and the Gdansk Deep. In these sediments, concentrations of pp'-DDT and its metabolites (pp'-DDE and pp'-DDD) ranged from 2 to 11 µg kg(-1) dw. Concentrations of HCB were between 0.1 and 1.0 µg kg(-1) dw. Concentrations of the sum of α-, ß-, γ-HCH were between 0.3 and 2.58 µg kg(-1) dw. Concentrations of marker PCBs ranged from about 2 to 11 µg kg(-1) dry weight. Total TEQ PCDD/F/dl-PCB values in the studied samples varied between 1 and 18 ng kg(-1) dw. The data were evaluated in terms of ecotoxicological criteria based on the environmental impact of the pollutant effects. Our research indicated that in the sediment from the southern Baltic Sea, the PCDD/F and PCBs occurred at concentrations which could be dangerous to marine organisms.

Marine and farmed fish on the Polish market: comparison of the nutritive value and human exposure to PCDD/Fs and other contaminants.

Chemical analyses were performed in nine fish species that are popular on the Polish market. These included Baltic fish (cod, herring, salmon), fish farmed in Poland (carp, trout), marine fish imported from China (Alaska pollock, sole), and farmed fish imported from Vietnam and China (sutchi catfish, tilapia). The nutritional composition (amino acid, micro- and macronutrients, fat-soluble vitamins - A(1), D(3), E) and certain contaminants (organochlorine pesticides, OCPs; indicator polychlorinated biphenyl, PCB(6); polychlorinated dibenzo-paradioxins and polychlorinated dibenzofurans, PCDD/Fs; dioxin-like polychlorinated biphenyls, dl-PCBs; organotin compounds, OCTs; dyes, malachite green and crystal violet; veterinary drug residues, nitrofurans and chloramphenicol; toxic metals, Cd, Pb, Hg) in the muscle tissues of fish were determined. It was confirmed that the fish species analyzed were excellent sources of amino acids, and were rich in phosphorous and selenium. Baltic Sea fish (salmon, herring), fish farmed in Poland (carp and trout), and tilapia were also rich in vitamin D(3). Traces of OCP, PCB(6), OCT, dyes, veterinary drug residues, and heavy metals were detected in concentrations which do not pose a threat to consumers at the current rate of fish consumption in Poland. However, the problem might arise from the content of PCDD/Fs and dl-PCBs in fatty Baltic fish. The fish species analyzed, differed in their nutritional values and degrees of contamination. We suggest that for optimum health and safety, it is advisable that consumers include a variety of different fish species in their diets.

Organochlorine pollutants in European eel (Anguilla anguilla L.) from Poland.

The purpose of the current paper is to report the levels of OC pesticides ([summation operator]HCHs, HCB, [summation operator]DDTs), marker PCBs, PCDD/Fs, and dl-PCBs in the muscle tissue of European eel, Anguilla anguilla (L.), collected in the Vistula and Szczecin lagoons (Poland), and in the local market. The results obtained were evaluated according to maximum limits adopted by EU, and some national legislatures. The intake of organochlorine contaminants from the consumption of eel from Polish waters is also estimated. The residues of tested contaminants ranged between: 0.6 and 6.0 ng g(-1)ww for [summation operator]HCHs; 9.8 and 273.9 ng g(-1)ww for [summation operator]DDTs; 0.4 and 23.8 ng g(-1)ww for HCB; 4.0 and 533.9 ng g(-1)ww [summation operator](7)PCBs; 0.72 and 8.14 pg-WHO-TEQ g(-1) ww for [summation operator]PCDD/F/DL-PCBs. The levels of OCPs, and PCDD/F/dl-PCBs in the muscle tissues of eels captured in the Vistula and Szczecin lagoons were compliant with European regulations.

Polybrominated diphenyl ethers (PBDEs) in selected fish species from the southern Baltic Sea.

This paper reports concentrations of seven polybrominated diphenyl ether (PBDE) congeners in selected fish species that were collected from the southern Baltic in the 2004-2006 period. Differences in concentrations of PBDEs among the fish species were observed. The mean summation Sigma(7)PBDE concentrations measured in herring (Clupeaharengus), sprat (Sprattus sprattus), and salmon (Salmo salar) samples were 1.2 ng g(-1) wet weight, 1.6 ng g(-1) wet weight, and 2.5 ng g(-1) wet weight, respectively. PBDE-47 was the prevalent congener in all the samples tested. PBDE concentrations in the herring samples tested in the current study were similar to those determined in herring sampled in the northern Baltic, but slightly lower in comparison with concentrations in fish from the Belgian North Sea. PBDE levels occurring in salmon sampled in the southern Baltic were lower than those measured in the northern and northeastern Baltic, but similar to levels determined in salmon from the central part of the Baltic Sea. The risk posed by consuming the fish tested in the current study was evaluated according to the Provisional Tolerable Weekly Intake (PTWI) value for PBDEs recommended by the European Food Safety Authority (EFSA).

Fish products available in Polish market--assessment of the nutritive value and human exposure to dioxins and other contaminants.

Chemical analyses were performed on one hundred and twenty of the most popular varieties of fish products (smoked fish, salted fish, and marinated fish) of the fish market in Poland. The contents of the nutritive substances of fish products (protein, micro- and macronutrients, vitamins A(1), D(3), E, and fatty acids) and the chosen contaminant (toxic metals--mercury, cadmium, lead, arsenic; dioxin/furans--PCDDFs; dioxin-like PCB--dl-PCBs; seven congeners of polybrominated diphenyl ethers--PBDEs; organochlorine pesticides--SigmaDDT, HCB, SigmaHCH and marker polychlorinated biphenyls--PCB(7)) levels were determined. It was confirmed that fish products are a good source of digestible proteins, iodine, selenium, and vitamin D(3). The fundamental nutritive benefit of processed fish lies in its highly beneficial fatty acid composition, which is what imparts them healthy nutritive qualities. The high content of long-chain polyunsaturated fatty acids (LC-PUFAs), which is not noted in other food products, is particularly important. The majority of contaminants studied were present in low levels. The possible threats, particularly in the case of pregnant/nursing women and young children, can pose the levels of dioxin/furans (PCDD/Fs) and dioxin-like (dl-PCBs) in smoked Baltic salmon and smoked sprat, elevated in a relation to particular requirements concerning the content of sum of PCDD/Fs and dl-PCBs in fish (8pg WHO-TEQg(-1)). The health benefits and risks stemming from consumption of fish products were determined according to the Provisional Tolerable Weekly Intake (PTWI) for chosen contaminants (Cd, Hg, As, PCDD/Fs+dl-PCB) and the quantity of ingredients that render a fish diet healthy based on data from the EFSA Journal [EFSA (European Food Safety Authority), 2005. Opinion of the scientific panel on contaminants in the food chain on a request from the European Parliament related to the safety assessment of wild and farmed fish. EFSA J. 236, 1-118]. In regard of high content of LC-PUFAa and other nutritive ingredients, fish products available in Polish market may be considered as healthy food. However, many authors point at contaminants (methylmercury, PCDD/Fs) occurring in fish and fish products as on potential health problem, and emphasize that the amount of that hazardous substances should be limited in human diet.

Study on the raw fish oil purification from PCDD/F and dl-PCB-industrial tests.

The results of tests for the purification of fish oils with activated carbon for industrial use are presented. The optimum parameters for the process of purification (granulation of the activated carbon, its dosage, the oil temperature, and the duration of mixing the oil with activated carbon) were previously established for the laboratory scale. The optimization of the process consisted of selecting purification parameters that would allow for maximum reduction of the toxic polychlorinated dibenzo-para-dioxins and polychlorinated dibenzofurans (PCDD/Fs) content, while retaining the favorable high fatty acid content [C20:5 n-3, eicosapentaenoic acid (EPA) and C22:6 n-3, docosahexaenoic acid (DHA)]. The use of that optimum parameters in industrial conditions confirmed the satisfactory results obtained in laboratory tests. Five types of oil derived from various Baltic fish were purified. Reduction in the PCDD/Fs content was 77.0-93.6% on average, whereas in the dioxin-like polychlorinated biphenyls (dl-PCBs)-it was 42.7-50.5% on average, with insignificant changes in the total amount of EPA and DHA content. Furthermore, a significant reduction in the content of arsenic was noted (by about 62% on average), with insignificant changes in the content of organochlorine pesticides (OCPs), and marker polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), cadmium, lead, and mercury. Purification provided fish oil having standardized parameters that allow for its use as feed additives, whilst retaining its favorable fatty acid content.

Investigation of PCDD/Fs and dl-PCBs in fish from the southern Baltic Sea during the 2002-2006 period.

Concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (dl-PCBs) in the southern Baltic herring (Clupea harengus), sprat (Sprattus sprattus), and salmon (Salmo salar) are reported. The significant interspecies and season-specific differences in PCDD/Fs and dl-PCBs concentrations were observed. The contribution of dl-PCBs to the total toxicity equivalents (TEQs) ranged between 50% and 70%, dependently on fish species. In all samples, concentrations of PCDF were higher in comparison with that of PCDD. The permissible limits of the content of PCDD/Fs and dl-PCBs (8 pg g(-1) fresh weight for the sum of PCDD/Fs and dl-PCBs, and 4 pg g(-1) fresh weight for the PCDD/Fs) were exceeded mainly in salmon samples (in 80% of salmon samples studied). The elevated levels of PCDD/F and dl-PCB were observed only in two of seventy two herring samples, and in ten of 62 sprat samples. The multiple regression analysis revealed that fish lipid content, and concentration of PCB 153, used simultaneously, might be useful in the prediction of TEQ values of fish samples. These two variables explained more than 80% of total variance. For all fish species studied, the correlation coefficients obtained with the multiple regression analysis were higher than that obtained with the regression analysis involving total TEQ values, and only one independent variable: fish lipid content.

PCBs in fish from the southern Baltic Sea: levels, bioaccumulation features, and temporal trends during the period from 1997 to 2006.

Levels of seven marker polychlorinated biphenyls (PCBs) have been determined in five species of Baltic fish collected during 1997-2006. Downward time trends in the concentrations of heavier congeners of PCBs in different Baltic fish, with the exception of cod, have been observed between 1997 and 2001. In case of sprat and herring samples, the statistical significance of the time trends of the PCBs: 101, 118, 153, 138 and 180 concentrations has been proved. Species-specific bioaccumulation of PCBs has been indicated, and the lowest and highest levels of PCBs (expressed on the basis of lipid weight) have been observed in sprat and salmon samples, respectively. PCB profiles have been found to be similar in all the fish species tested. Sampling location has not been a crucial factor for the observed levels of various PCBs. In some fish species, PCB concentrations are negatively correlated with the fat content but have no relation with the fish length.

Organochlorine pesticides in fish from the southern Baltic Sea: levels, bioaccumulation features and temporal trends during the 1995-2006 period.

The levels of HCH isomers, HCB and summation DDTs were determined in five species of Baltic fish collected during 1995-2006. Some downward time trends of HCH isomer, pp'-DDE and pp'-DDD concentrations in Baltic fish were observed; in contrast, HCB and DDT concentrations did not exhibit any obvious trend. Concentrations of summation HCHs expressed on a lipid weight basis were very similar in all species studied. In contrast, concentrations of summation DDTs varied in tested species. The most abundant HCH isomer was beta-HCH and among DDT-related compounds, pp'-DDE prevailed. In our investigations the sampling sites were not a crucial factor for organochlorine pesticide concentrations and patterns observed in fish, but the occurrence of several inter-species differences in the bioaccumulation features of OC pesticides were observed. For cod there was a positive correlation between fish size (length) and summation DDT concentration. In herring, sprat and salmon samples, summation DDT concentrations were negatively correlated with fat content.

[Macro- and microelements in canned sprats]. / Makro i mikroelementy w konserwach ze szprotów.

The content of macro- and microelements and toxic metals in the most popular canned sprat was described in this paper. The research included the following canned sprat: sprat in tomato, smoked and steamed sprat in oil. The following analyses were carried out: content of calcium, phosphorus, potassium, magnesium, copper, zinc, iron, manganese, chromium, selenium, fluorine, iodine, cadmium, lead, mercury and arsenic. Fluorine, iodine, selenium, and calcium and phosphorous are provided to customer organism in large amount by canned sprat, however canned sprat cannot be considered as a source of copper, chromium, and manganese. On the base of assessment data one canned sprat (weight 170 g) provides to customer organism more than 50% recommended daily intake of calcium and phosphorus, 85-233% fluorine, 62.5% iodine, 43% recommended selenium, more than 25% zinc, about 15% daily intake of magnesium, potassium and iron. It was found that all of the analyzed canned sprat contained relatively low content of cadmium, lead, mercury and arsenic, thus confirming the established safety standards.