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  1. 1. Vitamin B12:Anemia Mousa’ab Abdulrhman R. R
  2. 2. So how do we start !
  3. 3. 36 years male presented to the clinic with3 month history of tiredness and SOB after Jogging
  4. 4. Basics Hx P/E Dx Tx
  5. 5. Anemia Pathophysiology ClassificationBasics Hx P/E Dx Tx
  6. 6. FactMost common cause of anemia is blood loss
  7. 7. Basics
  8. 8. Function Of Vitamin B12 :Important for metabolism.Formation of red blood cells .Maintenance of the central nervous system..
  9. 9. Folate Vs B12 Etiology Arrest of Erythrocyte Mutation Arrest of Methonoin Formation Within Months Within Years Onset Symptoms of Anemia Symptoms of AnemiaPresentation Never Neurological Neurological Symptoms Are Common Lab Folate decrease B12 decreaseHomocysteine Decrease IncreaseMethylmalonic Acid WNL Increase
  10. 10. FactFolic Acid Supplement Can Mask Vitamin B12 Deficiency
  11. 11. Basics Hx P/E Dx Tx
  12. 12. Fact Supplement !Vitamin B12 is naturally available for human use onlythrough ingestion of animal proteins. Unfortified plant-based foods do not contain vitamin B12.
  13. 13. Fact Vit B12 daily ConsumptionThe dietary reference intake for an adult ranges from 2 to 3 µg per day
  14. 14. FactVit B12 “cobalamin” , is a water-soluble vitamin
  15. 15. Basics Hx P/E Dx Tx
  16. 16. Fact Decreased absorption/Interactions!Aminosalicylic acid can reduce oral vitamin B12 absorption,Excessive alcohol intakeReduced vitamin B12 levels may be more common with PPIs than with H2-blockersFolic acid particularly in large dosesAnticonvulsants Phenytoin, phenobarbitalNitrous oxideNicotineNeomycinMetformin (Glucophage)Hormonal contraception
  17. 17. Most likely Populations to Get B12 DeficiencyBasics Hx P/E Dx Tx
  18. 18. Fact Ask about Drugs !Oral contraceptive users generally have lowerserum vitamin B12 levels than nonusers
  19. 19. Fact Ask about Diet !Nursing infants of mothers who adhere to astrict vegetarian or vegan diet throughout theirpregnancy and while breastfeeding might alsoexperience serious B12- related deficiencyeffects ,Even when the mother is not anemic orsymptomatic in any way.
  20. 20. Basics During a checkup for HTN, a 65-year-old Hx female reports a 2-month history of tiredness, feeling faint from “getting up too fast”, and “memory problems”. P/E Dx Tx
  21. 21. FactAll patients newly diagnosed with unexplainedcognitive decline or dementia should beassessed for a possible vitamin B12 deficiency
  22. 22. What may lead to depletion and deficiency?Basics Hx P/E Dx Tx
  23. 23. FactPernicious anemia is an autoimmune disease inwhich antibodies attack gastric cells, resulting inimpaired production of intrinsic factor that is critical forabsorption of vitamin B12.
  24. 24. FactPernicious anemia, is the most common causeof B12 deficiency WorldWide , but In the US,most cases of vitamin B12 deficiency are due tomalabsorption.
  25. 25. Surgical ProcedureIleal resection >20 Cm
  26. 26. Fact During Surgery !Nitrous oxide causes the inactivation of vitaminB12, which might result in acute hematologic orneurologic complications of vitamin B12 deficiency.Because nitrous oxide is a commonly usedanesthetic in surgery, people at risk (e.g., theelderly) should be monitored for a developingsymptomatic vitamin B12 deficiency.
  27. 27. Bariatricsurgery
  28. 28. FactNo single symptom, or cluster of symptoms, hasbeen uniquely associated with inadequate levelsof vitamin B12.
  29. 29. Fact The Most CommonToday, megaloblastic anemia is most likelydue to a vitamin B12 deficiency until provenotherwise
  30. 30. What are the symptoms of B12 deficiency?Basics Hx P/E Dx Tx
  31. 31. Basics Hx P/E Dx Tx
  32. 32. Basics Hx Neuropathy Chronic P/E Distal & Symmetrical, Usually Legs First Common in Alcoholic Dx Sensory + Motor Tx
  33. 33. Vit B12 is Common e.g of Metabolic Neuropathy
  34. 34. Who should be Tested For B12 deficiency?Basics Hx P/E Dx Tx
  35. 35. Order:Basics Complete blood count (CBC) Peripheral blood smear Serum cobalamin (B12) Hx Not all patients with a vitamin B12 deficiency will have hematologic P/E manifestations. Dx a low serum B12 level does not automatically mean a deficiency. Tx
  36. 36. Fact Falsely low values !have been associated with :Multiple myelomaOral contraceptivesFolate deficiencyPregnancy
  37. 37. Fact Falsely Normal values !have been associated with :Liver diseaseMyeloproliferative disorders Polycythemia veraRenal insufficiency Essential thrombocytosis Myelofibrosis Chronic myelogenous leukemia (CML) So it is important to evaluate further.
  38. 38. Basics So What To do ? Hx Complete blood count (CBC) Peripheral blood smear Serum cobalamin (B12) P/E Dx Are Not Specific , Nor Accurate Tx
  39. 39. Confirmatory Testing By far, the most common, accurate, and widely used confirmatory tests for identifying vitamin B12 deficiency are tests for...... Homocysteine (Hcy) Methylmalonic Acid (MMA) is a sensitive indicator for a vitamin B12 deficiencylow levels of vitamin B12 increases in total serum Hcy. Shilling Test Differentiate b/w Nutritional B12 def. vs IF Not Used Anymore !
  40. 40. Basics Hx P/E Dx Tx
  41. 41. Basics There is no gold standard for determining cobalamin deficiency. Hx P/E Dx Tx
  42. 42. Prevention !To prevent a vitamin B12 deficiency, you should advise allpatients 51 years of age or older to consume syntheticvitamin B12 daily. Dosage recommendations vary.
  43. 43. Fact High vitamin B12 level in elderly individuals mayprotect against brain atrophy or shrinkage associated with Alzheimers disease and impaired cognitive function
  44. 44. Basics Hx P/E Dx Tx
  45. 45. Fact Adverse Effect !Vitamin B12:has extremely low toxicity and eventaking it in enormous doses appears not tobe harmful to healthy individuals.
  46. 46. Fact ReplacementCobalamin replacement is effective becausecrystalline forms of B12 can be absorbed evenwhen animal protein-bound forms cannot bedigested.
  47. 47. Fact Vitamin B12 is used to treat : Vitamin B12 deficiency Cyanide poisoning Hereditary deficiency of transcobalamin II.
  48. 48. Vitamin B12 is Not carcinogenic, teratogenic, or mutagenicIt is considered safe even at 1,000 times the RDA.