In Vitro Evaluation of Bioavailability of Se from Daily Food Rations and Dietary Supplements

Abstract

Bioavailability refers to a fraction of a substance that is potentially absorbed from the gastrointestinal tract and enters the systemic circulation (blood). This term is related to various substances, including minerals, that are present in a complex matrix of food which is consumed every day as natural products and pharmaceutical preparations, e.g., dietary supplements. The purpose of the study was to assess the bioavailability of Se from selected dietary supplements, with the simultaneous assessment of the effect the diet type (standard, basic and high-residue diets) has on relative bioavailability. The research included a two-stage in vitro model of digestion using cellulose dialysis tubes of the food rations with the addition of dietary supplements. Se was determined using the ICP-OES method. The bioavailability of Se from dietary supplements, in the presence of food matrix, was determined to be within the range of 19.31–66.10%. Sodium selenate was characterized by the highest value of this parameter, followed by organic forms and sodium selenite. The basic diet, characterized by moderate protein and high carbohydrate and fiber contents, positively influenced the bioavailability of Se. The bioavailability of Se was also influenced by the pharmaceutical form of the product—the highest was for tablets, followed by capsules and coated tablets.

In Vitro Evaluation of Bioavailability of Cr from Daily Food Rations and Dietary Supplements from the Polish Market

“…The significant influence of the type of diet was proven, and the highest results were observed in models using the basic diet, followed by high-residue and standard diets. It is hard to find a similar study in the literature on the subject to compare the obtained results with those of other authors, but our previous research, performed for Se, also indicated a positive influence of a basic diet on the bioavailability of this element [30]. In general, inorganic forms of Cr are characterized by the lowest values of bioavailability.…”

“…The exact procedure that was developed to prepare and reconstruct DFRs was previously described in detail [30]. Briefly, all food products came from the retail market in the Lublin region.…”

“…The majority of them (cereal products, milk and milk products, meat and meat products, eggs, vegetables, and fruits) were of local origin. The dishes were prepared and cooked in the laboratory according to local culinary practices, based on the guidelines presented in the available literature, and using a procedure that had been previously checked and validated [30][31][32][33][34]. The qualitative and quantitative composition of all DFRs used in the study was identical to those designed, reflecting the actual diet of the population.…”

“…The procedure used in the present study was improved and previously checked and validated for its accuracy in evaluating the bioavailability of various food components, including trace elements. All the details were described elsewhere [30,36].…”

“…The obtained samples (both fractions-the dialysate and the tube reside) were digested as previously described [30]. Briefly, DigiPREP MS (SCP Science, Canada) equipment with a condensate recirculation system was used.…”