Sudden numbness in the hands and feet: If your limbs (including the face) go numb, it could be a sign of a stroke. It is crucial not to ignore such symptoms, especially if they are unilateral ...

He added that B12 deficiency "can be undiagnosed or underdiagnosed since symptoms can be nonspecific," like cognitive slowing, fatigue, tongue swelling, arm or leg tingling, and difficulty walking.