The World Anti-Doping Agency (WADA) has restrictions for competitive athletes using intravenous (IV) infusions, particularly large-volume infusions. These rules are in place to maintain a level playing field in sports, for various reasons. 

According to WADA, any IV infusion of more than 100 mL in any 12 hour period is a Prohibited Method, unless it is administered in a specified clinical setting for legitimate medical reasons.

The clinical setting is defined as a necessary treatment as part of a:
1. hospital admission, or
2. surgical procedure, or
3. diagnostic procedure such as an EGD, MRI, or CT scan. 

For instance, administeration of cyanocobalamin (Vitamin B12) in 1000 mL Normal Saline IV in an outpatient setting, hydration clinic, or at home is prohibited; that means not allowed. Hydration clinics

(either a physical location or mobile clinic), usually inject people for non-medical purposes, without asking if the person is an athlete. This raises questions about the liability and responsibility of healthcare professionals in these settings offering  treatments prohibited under antidoping code. Even more concerning is staff telling an athlete the substance is not prohibited but overlooking the Prohibited Method, misinforming the athlete. 

Convervely, an IV infusion of vancomycin 1000 mg in 250 mL Normal Saline, given every 8 hours in a hospital setting for an infection, is permissible. In this case, the administration is for legitimate medical treatment aligning with WADA's guidelines for administration in the hospital setting. 

The distinction between these two scenarios underscores the importance of context in the application of anti-doping regulations, reinforcing that medical necessity and setting play crucial roles in determining the appropriate use of IV infusions in sports, regardless of the status of the medication in the IV fluid.