An elderly woman consults a physician because she is “feeling so tired all the time”

An elderly woman consults a physician because she is “feeling so tired all the time”. Intraoffice hematocrit is 35%. Peripheral blood smear shows many macrocytic red cells. On questioning, the woman, whose finances are limited, admits that has been living on a “tea and toast” type diet. She has been drinking a powdered orange juice substitute (Tang). She has not been taking vitamin pills because she feels she can’t afford them. A nutritional deficiency of which of the following is the most likely cause of this patient’s anemia?

A. Folate
B. Iron
C. Vitamin B12
D. Vitamin C
E. Vitamin K

The correct answer is A.

In real life, you would evaluate this woman for deficiencies in iron, folate, and Vitamin B12, since a woman with a diet this poor may very well have multiple problems. However, for the purpose of this type of test question, you should reason as follows: both vitamin B12 and folate deficiency can cause megaloblastic anemia. The patient’s “tea and toast” diet is much more suggestive of folate deficiency than B12 deficiency. Folate is widely found in plant and animal tissues, but is easily destroyed by over-cooking. Particularly vulnerable populations include the elderly, alcoholics, chronic liver disease patients, pregnant women, tropical sprue patients, chronic hemolytic anemia patients, and patients being treated (usually chronically) with certain medications (anti-convulsants, oral contraceptives, antimetabolites, and antibiotics that interrupt folate metabolism).

Iron deficiency (choice B) causes a microcytic anemia.

Vitamin B12 deficiency (choice C) is an important cause of megaloblastic anemia, but is more likely to be related to chronic gastritis with destruction of intrinsic factor-secreting parietal cells (pernicious anemia), fish tapeworm infestation, or malabsorption.

Vitamin C deficiency (choice D) is an occasional cause of megaloblastic anemia (often in conjunction with mild folate deficiency), but this patient is drinking a vitamin C-containing orange juice substitute.

Vitamin K deficiency (choice E) is usually related to either malabsorption or intestinal parasitic infection, and causes a bleeding tendency (because it is needed for synthesis of many clotting factors) rather than anemia.

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Dr. Lawrence Kindo

I am a medical blogger who loves to share interesting health stuff. This blog is dedicated to dissemination of medical MCQs. Enjoy!

7 comments… add one
  • dr.janan al-khayat

    Vit B12 deficiency is the correct answer in my opinoin. As per the explanation given , Folate is widely found in plant and animal tissues, so she is likely to maintain some of it in the vegatables or fruits that she is eating .But Vit 12 is mainly available in animal tissues [which she cannot afford to buy ] hence after several years of such restricted diet she is more likely to develop B12 deficiency [rather than Folte ]aneamia .Besides ,atrophic gastritis frequency increase with age [ need not to be autoimmune ] which exposes her to intrinsic factor defficiency .

  • dr wajeeha anjum

    affirmatve! supports reply by dr janan al-khayat

  • dr. alfy

    suspicious with b12 def

  • Richrd

    The question does not give any physical signs that this is B12 def. NO PHYSICAL SIGN. Only the macrocytic change. This is folate def.
    If the author wanted you to say B12 def, they would have mentioned something about Neurological symptoms: Sensory or motor deficiencies (absent reflexes, diminished vibration or soft touch sensation).

    • Hi Richrd,

      I am with you here. Absence of neurological symptoms in the question should lead to Folate deficiency!

  • Richrd

    Also, the total body stores 3-4 yrs worth of B12. Takes 3-4 years to get deficient. Folate on the other hand takes 3-6 months to be deficient.

    What matters is NOT your opinion, but FACT. Try not to practice “my opinion is…” without background knowledge.

    • Excellent point about the total body stores of B12 and Folate.

      Chill it with the subsequent taunt. This is an open platform and discussion is key to keep things going. You are both welcome here!

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