http://www.ncbi.nlm.nih.gov/pmc/articles/PMC489070/
There are many footnotes to support these statements."Multiple sclerosis and vitamin B12 metabolism"
… It is remarkable that, despite the fact that the age range is so different, the sex, racial and geographical distribution of MS and PA [pernicious anemia – the extreme form of B12 deficiency] are similar. Thus PA is a higher prevalence in northern Europe compared with Southern Europe in tropical areas, a diminishing prevalence from the north to the south of the UK and a higher incidence in white than black North Americans. The female-to-male ratio in both disorders is 1-3:1. Najim Al-Din et al have also drawn attention to some similarities in the HLA associations of MS and PA.…
Must watch: "Everything You Want Your Doctor to Know about Vitamin B12"
I highly recommend this 50-minute documentary from the filmmaker Elissa Leonard, featuring Sally M. Pacholok, RN, BSN & her husband Jeffrey J. Stuart, D.O. (authors of the book, Could It Be B12? An Epidemic of Misdiagnoses); Lawrence Solomon, M.D., hematologist with Yale Medical School; Ralph Green, M.D., hematologist at UC Davis; and Donald Jacobsen, PhD, at the Cleveland Clinic (Homocysteine Research Lab).
@1:23 "The neurological manifestations well precede the hematological manifestations."
@1:46 "In 1948 scientists isolated a red crystalline pigment and named it vitamin B12. It is a primordial molecule responsible for the health of all the DNA in all our cells. The Framingham Offspring Study suggests 40% of Americans have suboptimal B12."
Cardinal Signs of Anemia Due to Vitamin B12 Deficiency:
Fatigue
Shortness of breath
Dizziness
Pale/yellowish skin
Swollen tongue that may appear dark red
Weight loss
Diarrhea
Numbness or tingling in your hands and legs
Muscle weakness
Irritability
Unsteady movements
Mental confusion or forgetfulness
Signs and Symptoms of B12 Deficiency:
#1 Peripheral Neuropathy
Tingling/Numbness
Sore Mouth or Tongue
Fatigue
Anxiety
Irritability
Depression
Weakness
Abnormal Gait
Mental Impairment
Visual Disturbances
Migraine
Orthostatic Intolerance
Chest Pain
Tachycardia
Difficulty Breathing
Edema
Elevated Homocysteine
Elevated MMA
Stomach and G.I. Problems
Blood Abnormalities
Neurological Lesions
Limb Movement Disorders
Psychosis
Thoughts of Suicide
Risk factors for B12 deficiency:
Vegetarian Diet
Pregnancy
Age over 50
Low Stomach Acid
Celiac Disease
Food Allergies
Eating Disorders Parasites
Use of Acid-Blockers
Use of Oral Birth Control Pills
Use of Metformin
Nitrous Oxide Anesthesia
Pernicious Anemia
Autoimmune Disorders
Pancreatic Insufficiency
Stomach Surgery
Intestinal Bacterial Overgrowth
Peptic Ulcer
Transcobalamin Deficiency
Their website: http://b12awareness.org/