Case discussion is an effective way to instil biochemistry into the minds of young medical students. Here, Dr Karthikeyan discusses vitamins. Don\t forget to watch the YouTube video inside

1. Case discussions
An effective way to instill biochemistry into the mind
of medical student

2. Case discussion on Vitamins

3. A 32-year-old body builder has decided to go on a diet
consisting of raw egg whites with the misconception to
ensure high proteins for his muscle growth. After a few
weeks, he experienced easy fatigability after moderate
exercise. He visited the nearby hospital and is found to be
hypoglycemic. After correcting his blood glucose levels,
the physician prescribed biotin supplement and sent to
patient for nutritionist counselling.

4. • What is the cause of Biotin deficiency in this patient?

5. • What is the role of avidin in egg white?

6. • How many molecules of biotin are bound by avidin?

7. • Can prokaryotes produce avidin?

8. • What is the use of streptavidin?

9. • Name 4 reactions that require biotin.

10. • Does all carboxylase reactions require biotin?

11. • Name 3-biotin dependant carboxylation reactions

12. • Decreased activity which enzyme could have been the cause of
hypoglycemia in this person?

13. A 44-year-old vegan presented to his physician complaining of
fatigue, muscle weakness, and depression.
The initial laboratory profile included a haematological
analysis that showed that he had macrocytic anemia. A bone
marrow aspirate showed hyperproliferative marrow with
megaloblasts. Further analyses revealed that his serum folic
acid level was 1.2 ng/mL (normal 2.5 to20), his serum B12
level report was awaited, but his serum iron level was normal.

14. • Despite of folate being present in green leafy vegetable, how this
person is suffering from folate deficiency?

15. • Treating this person with folate alone is inadequate, why?

16. • Name the only two vitamin B12 requiring enzymes in the body.
Decreased activity of which enzyme is responsible for the
haematological symptoms?

17. • Treating this person with folate alone is inadequate, why?

18. A 32-year-old male reported to the emergency with active
bleeding from nose. History revealed that he had been on
Orlistat for weight reduction for the past two years. He had
started Orlistat without the advice of any practitioner and
had lost nearly 20 kg of body weight. There was no history
of hypertension, bleeding disorder or any other medical
illness. No such bleeding episode occurred in the past.
There was no abnormality detected upon local examination
of nose.

19. • What is the relationship between Orlistat and epistaxis in this person?

20. • The person is taking orlistat for the past 2-years. Why bleeding didn’t
happen earlier? Why now?

21. • Will biliary obstruction also produce similar kind of symptoms?

22. On a Sunday afternoon, a 37-year-old chronic alcoholic was brought
to the emergency with complains of altered sensorium. The
resident on duty checked his blood sugar using point of care testing
device and found the glucose level of 40 mg/dL. Immediately he
started 25% dextrose infusion. He expected the patient to recover.
But, the condition of the patient worsened. Blood gas analysis and
electrolyte measurement revealed a significant metabolic acidosis
with high anion gap. The resident called the senior and the senior
advised him to inject a vitamin to the patient.

23. • Which vitamin could be that?

24. • Name 4 thiamine dependant reactions in the body?

25. • Increased dietary intake of carbohydrates increases the RDA of
thiamine. Why?

26. • Why chronic alcoholics are prone to this vitamin deficiency?

27. • How will you explain the metabolic acidosis with high anion gap?