Which of the following is NOT an IV solution?

In the context of intravenous (IV) solutions, the correct choice pertains to what constitutes an appropriate solution for intravenous administration. Dextrose 5% in water, normal saline, and dextrose/normal saline are all IV solutions used for hydration, electrolyte management, or nutritional support. These solutions are designed for safe delivery into the bloodstream, ensuring appropriate osmolarity and compatibility with blood components.

Calcium carbonate, on the other hand, does not qualify as an IV solution. It is primarily an oral supplement used to treat or prevent deficiencies, particularly in calcium. When considering formulations for intravenous use, it is essential that the solution not only dissolves properly but also is sterile and free from particles that could cause complications if administered. Calcium carbonate is not typically used in IV formulations due to its insolubility in water and the potential for precipitation, making it incompatible with IV therapies. Therefore, understanding the specific uses and properties of these solutions clarifies why calcium carbonate is not an appropriate IV solution.