Question

Which of the following is the richest source of vitamin B12?

• A. Meat
• B. Green leafy vegetables
• C. Corn oil
• D. Sunflower oil

Hint:

B12 comes only from animal products, never from plant oils or greens.

Answer 1

The Correct Option is A

Clinical pearl: vitamin B12 is the one vitamin a pure vegetarian cannot get from natural food, because no plant makes it. Use that fact to sort the options. Green leafy vegetables, corn oil and sunflower oil are all plant derived, so none of them supply B12, and you can cross out three options in one stroke.
The only animal-derived choice left is meat, which is the correct answer. Animal tissues, particularly liver, concentrate B12 along with fish, eggs and dairy. This is why pernicious anaemia and dietary B12 deficiency are classically seen in long-standing vegans, who must rely on fortified breakfast cereals or supplements instead. So meat is the richest source listed.
Ref: DM Vasudevan, Textbook of Biochemistry, 6th edn.