Vitamin B12/Pernicious Anemia
Discuss respiratory signs and symptoms of pernicious anemia
(compensation for low Hgb) Dyspnea and orthopnea
Discuss cardiovascular signs and symptoms of pernicious anemia
(compensation for low Hgb) palpitations, tachycardia
What is the role of vitamin b12
1. essential for the DNA synthesis and nuclear maturation. 2. It leads to normal red blood cell maturation and division 3. Prevents abnormal fatty acids from being incorporated into neuronal lipids
Discuss the characteristics of pernicious anemia
1. megaloblastic anemia 2. abnormally large RBCs because of excess cytoplasmic growth and structural proteins 3. immature nuclei and signs cellular destruction 4. flimsy membranes that are oval 5. short lifespan.
How does pernicious anemia relate to vitamin B12 deficiency?
Atrophic gastritis and failure to produce intrinsic factor leads to inability to absorb vitamin b12. Linked with autoimmune destruction of gastric mucosa
Patients with pernicious anemia are at risk for what?
Gastric cancer. Upper GI endoscopy and biopsy may be done
How much B12 does the body store?
It can store 1000-5000mcg in the tissues, using only 1mcg per day, so deficiency occurs slowly
What does intrinsic factor do related to B12?
It helps to transport and protect B12 through stomach and protects it from being digested by intestinal enzymes
How does vitamin B12 deficiency develop related to intake?
It is found in animal products. So, often occurs for those that avoid animal products or have a malabsorption.
At what age is pernicious anemia typically diagnoses?
Usually develops are age 40 and diagnoses around 60 yrs old. Due to large stores of B12, years pass before it results in anemia
Another name for vitamin b12
cobalamin
Discuss possible causes of pernicious anemia
inflammation, neoplasms of terminal ileum, malabsorption syndromes (just think of the cascade)
Risk factors for B12 deficiency
long term use of PPI, GI disease (such as Sprue, Ileitis) Surgeries (Gastrectomy, Gastric bypass) Crohn's Disease, celiac disease, diverticula of small intestine
Discuss gastrointestinal signs and symptoms of pernicious anemia
nausea. Vomiting. Anorexia. Diarrhea. Constipation. Flatulence. Gingival bleeding and tongue inflammation (red, beefy, and shiny).
Discuss the process of B12 absorption in the body
release of b12 from animal source intrinsic factor secreted from parietal cell in gastric mucosal lining B12 binds to intrinsic factor the complex travels to ileum and binds to epithelial cells in membrane B12 is transported across membrane into circulation B12 is bound to carrier protein called transcobalamin II and carried to storage tissue
Discuss labs needing review and typical findings for pernicious anemia
serum cobalamin/vitamin b12 levels are reduces. Presence of parietal cell and intrinsic factor antibodies.
Discuss neurologic signs and symptoms of pernicious anemia
weakness. Fatigue. Peripheral numbness/paresthesia of feet and fingers. Disturbed position of sense. Lack of coordination/spastic ataxia. Altered vision. Altered taste/smell. Tinnitus. Low of bowel and bladder control. Impotence in males. Irritability. Poor memory. HA. Cerebral function may be affected in severe cases.