Vitamin B12, also known as cobalamin for the molecule of cobalt that forms part of its structure, is one of the B-complex family of vitamins. Though it is water-soluble, vitamin B12 can be stored in the liver for extended periods of time, according to the University of Maryland Medical Center. Vitamin B12 is used by every cell in the body and is particularly important in the management of the central nervous system.
Spinal Cord
Myelopathy--a disorder involving the spinal cord--is a condition that may arise from vitamin B12 deficiency, according to a study published in the December 2009 "Journal of Neurological Science." In a case reported in the study, the upper and middle parts of the patient's spinal cord were affected by the B12 deficiency. This resulted in bronchospasm characterized by wheezing, coughing and airway obstruction, an unusual symptom of vitamin B12 deficiency affecting the autonomic nervous system--the division of the nervous system which controls visceral functions, according to the researchers, P. Puntambekar et al., at the Department of Neurology, Wayne State University School of Medicine, Detroit, Michigan. In addition, the patient experienced motor difficulties and bladder dysfunction.
Optic Nerve
The optic nerve, which conveys visual images to the brain, can be affected in vitamin B12 deficiency, according to a report published in the October 2010 "Pediatrics" journal, which detailed three cases of visual loss in autistic children caused by B12 deficiency. The loss of vision occurred gradually and was partially reversed in all of the children via intramuscular injections of the vitamin and dietary improvements. The authors of the study, S. L. Pineles et al., at the Department of Neurology, University of Pennsylvania School of Medicine, noted that severe food selectivity and limited diets are a common complication in autism.
Balance
An elderly patient developed dizziness, balance problems and difficulty walking due to vitamin B12 deficiency, according to a report published in the December 2010 "Clinical Chimica Acta" journal. The symptoms began two days after surgery to implant a pacemaker and blood tests were negative for B12 deficiency; however, intravenous therapy with vitamin B12 was successful at reversing the patient's symptoms of dizziness, balance problems and difficulty walking. The authors, B. Singh et al., at G.B. Pant Hospital, New Delhi, India, urge awareness of this type of vitamin B12 deficiency syndrome, which they say is frequent in the elderly. The study underscores a condition in older people in which the transfer of B12 from the blood into the tissues is faulty, resulting in normal blood levels but deficiency in tissues where the vitamin is needed, according to the website DrMirkin.com.
Psychiatric Effects
Psychiatric changes can accompany vitamin B12 deficiency, according to a study by J. J. Graber et al., at Memorial Sloan-Kettering Cancer Center, New York. The study described a slowly progressive depression with loss of cognitive function and autonomic system dysfunction that occurred over a five-year period in an otherwise healthy 62-year-old woman. The patient's blood levels of vitamin B12 were within normal limits, as were homocysteine and methylmalonic acid levels--markers of B12 deficiency. Pernicious anemia was discovered through a test that showed antibodies to intrinsic factor and the condition was mostly reversed with intramuscular injections of vitamin B12. The study was published in the December 2010 "Journal of Neurology Neurosurgery and Psychiatry."
References
- PubMed.gov: Rare sensory and autonomic disturbances associated with vitamin B12 deficiency
- PubMed.gov: Vitamin B12 optic neuropathy in autism
- PubMed.gov: Acute presentation of dizziness in vitamin B12 deficient old patient of cardiac disease: a case report
- PubMed.gov: Vitamin B12-responsive severe leukoencephalopathy and autonomic dysfunction in a patient with "normal" serum B12 levels
- MedlinePlus: Anemia - B12 deficiency
- University of Maryland Medical Center: Vitamin B12 - Overview
