Intro to the Top 5 Intracellular Deficiencies I see with MTHFR - this is part 1 - more coming very soon. If you’re struggling with fatigue that never seems to end, there’s a reason for that and it’s locked in your genes. MTHFR affects 85% of the US population and we wonder why we’re all tired and anxious. Let’s give your cells the energy boost they crave.