What is the recommended magnesium/calcium ratio to maintain the stability of total parenteral nutrition?

Total parenteral nutrition (TPN) is a vital treatment for patients who cannot receive oral or enteral feeding, providing all the necessary nutrients, including carbohydrates, lipids, amino acids, vitamins, minerals, and water. Due to its high osmolarity, it is primarily administered via a central route. However, in some cases, a peripheral route may be used, although with a lower nutritional content and higher infusion volume. One of the key aspects in preparing TPN is ensuring the physicochemical stability of the mixture. This is achieved through proper formulation and handling of electrolytes, among which calcium (Ca²⁺) and magnesium (Mg²⁺) play a crucial role. The relationship between calcium and magnesium is of particular importance, as these divalent cations directly affect the stability of the lipid emulsions in TPN. An imbalance in this ratio can lead to undesirable interactions with other components of the mixture, such as phosphates, which may result in the formation of precipitates and, consequently, the destabilization of the solution, compromising its effectiveness and safety. This communication will address the significance of the magnesium/calcium ratio in TPN stability and how this balance is critical in preventing complications during treatment administration.