If a patient without a diagnosed vitamin B12 deficiency is receiving the vitamin through regular injections to experience the multitude of benefits, the frequency of these injections can vary quite a bit depending on the reason they are getting the injections (weight loss treatments will likely have a higher frequency of vitamin injections than other treatments) and this timeline will be established by the patient and the specialist providing the injections to ensure that the treatment is both as safe and as effective as possible
After finishing Choquequirao, they return to Cusco and a few days later start the Inca Trail, the train, or the Salkantay trek to Machu Picchu
Vitamin B12 is generally considered safe, even when taken in large doses
1,2,6,12 Dementia-like disease, including episodes of psychosis, is thought to be associated with more severe and chronic deficiency, although supporting evidence is poor
Private insurers might have more flexibility, but only if the notes are clear and the medical necessity is solid