Without intrinsic factor or a diet that contains the recommended intake of
vitamin B-12, the amount of
vitamin B-12 found in the body is decreased. When this occurs, these signs and symptoms of a vitamin B-12 deficiency occur: fatigue, shortness of breath, tingling and numbness in the extremities, headache, dementia, disorientation, and loss of concentration and memory.
In severe cases, a vitamin B-12 deficiency by permanently damage your nerves, leading to lifelong side effects.