Question

a loading dose of which of the following vitamins can cause serum b12 to appear lower than normal?
a) retinol
b) niacin
c) vitamin c
d) vitamin d

Explanation:

High - dose vitamin C can interfere with laboratory assays for serum B12. It can cause false - low results in some immunoassay methods used to measure serum B12 levels. Retinol (vitamin A), niacin (vitamin B3), and vitamin D do not have this specific interference with serum B12 measurement in the context of causing a false - low reading due to a loading dose in the way vitamin C does.

Answer:

C. Vitamin C