feline b12 injection site reaction Life Threatening Anemia treated with Food Therapy and in a 17 year old Vitamin B12 Deficiency in Cats:

The symptoms can be severe, and develop rapidly or over time

There are many reasons for constrained supply, including tight regulation due to its classification as a schedule II drug which the DEA defines as "drugs with a high potential for abuse, with use potentially leading to severe psychological or physical dependence." In addition, labor shortages, supply chain issues and an increase in the number of people who have been prescribed the drug in recent years may have an effect on supply

Does not address collagen or keratin deficiencies

A consultation with a specialist can help assess your suitability for this treatment

Inform your doctor about all medicines you are taking to avoid adverse interactions

It is found in a variety of foods such as fish, shellfish, meats, and dairy products