# Profiling the Spirulina Dietary Supplements Available on the Romanian Market
## 1 Introduction  
Over the last two decades, food supplement consumption has grown around the world. In addition, the market interest for these products increased during the COVID-19 pandemic, as a boost for the immune system [1]. In this context, one of the most consumed dietary supplements, worldwide, is spirulina. _Arthospira platensis_, commercially known as spirulina, is a filamentous cyanobacteria able to cope with high alkalinity, high temperature, and high salinity [2]. Cyanobacteria are defined as bacteria able to carry out oxygenic photosynthesis with water as an electron donor and reduce CO\({}_{2}\) as a source of carbon [3]. They are a morphologically and functionally diverse group of microorganisms responsible for maintaining important biogeochemical cycles, like oxygen production ordinitrogen fixation [4; 5]. Spirulina is highly valued as a dietary supplement, feed, and a cosmetic agent. It has high protein content (up to 70%), high free fatty acid content (up to 80% of total lipids), and relatively low carbohydrate content (up to 20%). It is also a good source of vitamins (A, B1, B2, B3, cyanocobalamin, E, etc.) [6] and minerals (iron, calcium, and magnesium). Moreover, spirulina has a long list of bioactive compounds, from chlorophyll, beta-carotenes, and xanthophyll to polysaccharides to peptides and proteins, the best known being the blue pigment phycocyanin, with the physiological function of a light-harvesting antenna and a powerful antioxidant in animal organisms [7]. As a result, multiple studies have reported antioxidant, antitumor, anti-inflammatory, immunostimulant, and hypoglycemic activities [8; 9; 10]. Spirulina is commonly sealed in different commercial forms, like powder, tablets, or capsules. While the powder formulation allows for further consumption either in its current form or incorporated into smoothies, energy bars, and various health foods, the pill form allows for controlled concentration intake. The formulation is not the only marketing strategy employed by producers. Beyond the easiness of intake, the suppliers can also add labels to influence customers' buying options, such as designations of organic product and produced from European Union (EU) agriculture, or vary the packaging type, which also can rise the selling price. The illusion of choice can affect vulnerable social groups that look for healthy options without having access to critical information regarding whether the marketing strategies influence the mineral contents of spirulina. While a plethora of studies [11; 12; 13; 14] have reported some sort of positive effect that would come out of consuming spirulina dietary supplements, these kinds of dietary additions are more often than not self-administered without medical or nutritionist advice. While one will simply equate the consumption of spirulina with adding more green leaves to one's diet, their unique physiology and diversity of active biological compounds make them a \"Swiss Army knife\" of nutrition. The beneficial properties of spirulina have been thoroughly investigated in the literature [15]. It has been demonstrated that the mineral content of spirulina can range appreciably depending on nutrient availability, culture conditions (e.g., pH, light intensity, and salinity), and purification [16; 17]. However, the composition and the nutritional proprieties of commercially accessible spirulina are scarcely studied in scientific papers [18; 19]. In this regard, [PERSON] et al. [20] conducted an elemental analysis on 33 samples from different countries of origin and observed that the supplement form and cultivation method affect the mineral content of spirulina.