This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
The mineral having sparing action on vitamin E 
Select and explain. 
A. Calcium, B. Iron, C. Iodine, D. Selenium
D: Selenium
Answer: D: Selenium 
Explanation: The element selenium  is found in the enzyme glutathione  peroxidase  that  destroys  free radicals.  Thus, Se is also involved  in antioxidant functions like vitamin E, and both of them act synergistically.  To a certain extent, Se can spare the requirement  vitamin E, and vice versa.
Ref : Satyanarayana, 3rd ed, pg. 129