Why Do I Feel Worse After My B12 Injection: 6 Body Reactions Feeling constantly tired, foggy, or run down? Vitamin B12 plays a key role in energy production and nervous system health and low levels can lead to fatigue, brain fog, and weakness. How Much Do B12 Injections Cost Near Me in Northglenn, CO? Feeling tired all the time but can't figure out why? Low Vitamin B12 often shows up as just fatigue before turning into something more serious. This article explains the hidden signs, who Feeling unusually tired and fatigued? Having tingling sensations in hands and fingers, or having balance and memory issues? These could be symptoms of Vitamin B12 deficiency. Get a comprehensive check with our