Vitamin B12 Deficiency
Original Editors - Aneta Petri & Katie Wilson from Bellarmine University's Pathophysiology of Complex Patient Problems project.
Top Contributors - Aneta Petri, Kathrine Wilson, Lucinda hampton, Kim Jackson, Elaine Lonnemann, Vidya Acharya, 127.0.0.1, Wendy Walker, WikiSysop, Lauren Lopez and Ahmed M Diab
Definition/Description[edit | edit source]
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Prevalence[edit | edit source]
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Characteristics/Clinical Presentation[edit | edit source]
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Associated Co-morbidities[edit | edit source]
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Medications[edit | edit source]
There are several different medications that can affect the absorption of vitamin B12. There is not sufficient or there is conflicting evidence that suggests these medcations might affect the asorption of Vitamin B12. Patients that use these medications should keep tract of their Vitamin B12 levels. Medications that can interfere with the absorption of Vitamin B12 include:
-Chloramphenicol (antibiotic) May interfere with the RBC response to Vit. B12
-Proton Pump Inhibitors (Prilosec) These medications slow down the absorption of Vit. B12. They do this because they slowly release acid into the stomach.
-H2 Receptor Antagonist (Pepcid, Zantac) These medications slow down the absorbtion of Vit. B12 by releasing hydrochloric acid into the stomach.
-Metformin (Hypoglycemic used for diabetes) May alter the mobility and bacteria in the intestines, or may alter the intrinsic factor needed to absorb Vit. B12.[1]
Diagnostic Tests/Lab Tests/Lab Values[edit | edit source]
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Etiology/Causes[edit | edit source]
There are many things that can cause a Vitamin B12 deficiency:
Lack of Intrinsic Factor:
A lack of intrinsic factor (IF) may cause a vitamin B12 deficiency. This is an essential protein in the small intestine that allows Vitamin B12 to be absorbed. Decreased production of IF can occur during middle age, leaving many elderly adults at risk. Atrophic gastritis can lead to decreased IF production. This is caused by aging, iron or folate deficiency, autoimmune disorders, endocrine disorders or infections. [2][3]
Malabsorption in the Small Intestine
There are several reasons why the Small intestine may not be able to absorb Vitamin B12:
The small intestine can have too much bacteria in it. The bacteria will take up space and not allow Vitamin B12 to be absorbed.
Certain diseases of the small intestine may decrease absorption of Vitamin B12 such as celiac disease, Chron’s disease, and HIV.
Surgery to the small intestine may interfere with absorption of Vitamin B12.
A tape worm in the small intestines would cause a decrease in absorption of Vitamin B12 into the body.[4]
Diet Lacking Vitamin B12
Many people can develop Vitamin B12 deficiencies by not eating enough foods that contain B12. [4]
Systemic Involvement[edit | edit source]
Vitamin B12 deficiency can cause hemotalogic, neurologic, gastrointestinal, and cardiovascular symptoms.
Hemotalogic
Hematologic pathology may cause the following symtoms: skin pallor, weakness, fatigue, syncope, shortness of breath, and palpitations.
Neurological
The most common neurological symptom is tingling in the hands and feet. Other possible neurological symptoms that could occur: paresthesia, weakness, motor deficits, loss of vision, behavioral changes, and cognitive changes.
Gastrointestinal
Gastrointestinal dysfunction can cause symptoms such as anorexia, flatulence, diarrhea, and constipation.
Cardiovascular
Vitamin B12 deficiency can lead to increased risk of coronary artery disease and stroke. Vitamin B12 deficiency causes hyperomocysteinemia which can increase occlusions in the vascular system. There is not a lot of evidence to prove that Vitamin B12 will cause vascular issues, but evidence does link the two together.
Medical Management (current best evidence)[edit | edit source]
Treatment: The most common treatment is Vitamin B12 supplements. Patients can also get Vitamin B12 shots, sublingual tablets, and nasal injections.
Recommended dietary amounts (RDAs) for Vitamin B12
Age Male Female
0-6 months .4 mcg 4 mcg
7-12 months .5 mcg .5 mcg
1-3 years .9 mcg . 9 mcg
4-8 years 1.2 mcg 1.2 mcg
9-13 years 1.8 mcg 1.8 mcg
14 and older 2.4 mcg 2.4 mcg
Pregnancy N/a 2.6 mcg
Breast Feeding N/a 2.8 mcg
Recommended suppliments:
Patient Male Female
>50 years old 25-100 mcg 25-100 mcg
Vitamin B12 deficiency 1 25-2000 mcg 125-2000 mcgs
Preventing Anemai 2-10 mcg 2-10 mcg
Physical Therapy Management (current best evidence)[edit | edit source]
An individual with a confirmed or suspected Vitamin B12 deficiency is typically treated by a primary physician with mediation that includes intramuscular injection, oral Vitamin B12 supplements, or through a change in nutritional habits. Treating or diagnosing a patient with a vitamin deficiency typically falls outside of the Physical Therapist Scope of Practice, however physical therapists should be aware of the presenting sign and symptoms of Vitamin B12 deficiency and refer to proper medical personnel with any unusual findings. Physical Therapists should be particularly familiar with the role Vitamin B12 on the nervous system. If a physical therapist suspects that a Vitamin B12 deficiency maybe present they should refer to MD. Early diagnosis of the deficiency is extremely important because the effect of treatments is believed to be linked to the time of diagnosis.
Vitamin B12 and the Nervous System:
Vitamin B12 acts as a co-enzyme that facilitates myelin synthesis. A defect in the myelin synthesis can lead to both central and peripheral nerve function abnormalities. Some conditions seen with this dysfunction include: myelopathy, neuropathy and optic nerve atrophy. Roughly 25% of individuals suffering from a vitamin B12 deficiency experience peripheral neuropathy. The spinal cord can become involved in severe deficiency and a syndrome often seen with this is sub-acute combined degeneration (SCD). MRI findings may reveal an inflammation of the spinal cord, most commonly reported at theT2 level.
Clinical presentations of SCD include:
- bilateral sensory deficits most commonly affecting bilateral lower extremities
- bilateral lower extremity weakness
- ataxia
- decreased proprioception and vibration sensation
- positive Rhombergs Sign
- abnormal reflexes
- spastic paresis
Alternative/Holistic Management (current best evidence)[edit | edit source]
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Differential Diagnosis[edit | edit source]
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Case Reports/ Case Studies[edit | edit source]
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Resources
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Recent Related Research (from Pubmed)[edit | edit source]
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References[edit | edit source]
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- ↑ Vitamin B12 [Internet]. [Place Unknown]: National Institutes of Health: Office of Dietary Suppliments;2009 [cited 2014 March 23]. Available at http://ods.od.nih.gov/factsheets/VitaminB12-HealthProfessional/#h5.
- ↑ Goodman CC, Fuller KS, Boissonnault WG. Pathology: Implications for the Physical Therapist.2nd ed. Philadelphia: Saunders Elsevier;2003
- ↑ Cite error: Invalid
<ref>tag; no text was provided for refs namedPernicius Anemia - ↑ 4.0 4.1 Pernicious Anemia [Internet]. [Place Unknown]: Nation Institutes of Health;2009 [cited 2014 March 21]. Available at:http://www.nhlbi.nih.gov/health/health-topics/topics/prnanmia/.
