Vitamins: practice question

The best answer is A, Vitamin B12. Vitamin B12 is needed to convert methylmalonyl-CoA to succinyl-CoA, so its deficiency raises methylmalonic acid.

Folate deficiency raises homocysteine but not methylmalonic acid.

Iron deficiency gives a microcytic anaemia.

B6 deficiency causes sideroblastic anaemia and neuropathy but not this pattern.

It tests Vitamins in Biochemistry. Folate deficiency causes megaloblastic anaemia too, but methylmalonic acid stays normal and there are no neurological signs.

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

Build one table of enzyme deficiency, disease, inheritance and key finding, then revise it by spaced recall. Then use the flashcards and the other Biochemistry questions on this site to test what stuck.

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.