Low energy & fatigue Feeling constantly tired, lacking energy, or struggling to stay awake could indicate a B12 shortage
Siegel, 1961): Absorption tests with food, using a flushing vitamin B12 injection to estimate absorption, indicate a reduction of the passive absorption by about 40% when supplements are taken with food rather than when fasting
Those systemic factors may include poor sleep, low protein intake, vitamin or mineral deficiencies, high inflammation, insulin resistance, thyroid issues, hormone changes, medication effects, excess training load, chronic stress, or inadequate rehabilitation
Not intended to diagnose, treat, cure, mitigate, or prevent any disease
How quickly do vitamin B12 injections start working