Last updated: March 9, 2026 If you are considering B12 injections this spring whether as part of a pre-summer wellness refresh or to address persistent fatigue understanding the risks is just as important as knowing the benefits
Understanding their origins helps clarify why they affect the body differently
It blocks an enzyme called NNMT, which consumes nicotinamide, a building block cells use to make NAD+
Metabolism, which was previously blocked by the lack if B12, also quickly consumes the other molecules like minerals and vitamins from your blood and you get an initial high from the B12 injection
Symptoms of Vitamin B-12 Deficiency Fatigue and Weakness Low Moods Low Concentration Level Loss of Appetite Constipation Poor Memory Foods Rich in Vitamin B-12 Beef and chicken liver Wild-caught fish such as salmon, trout, and tuna Grass-fed beef and lamb Pasture-raised poultry Organic dairy products like milk and yogurt Who Is Most Likely to Have a Vitamin B-12 Deficiency
Fleckenstein M, Keenan TDL, Guymer RH, Chakravarthy U, Schmitz-Valckenberg S, Klaver CC, Wong WT, Chew EY