BUN and creatinine levels may decrease in:

BUN and creatinine levels may decrease in:

• A. Adequate protein intake
• B. Excess protein intake
• C. Dehydration
• D. Inadequate protein intake

Answer: (D)

BUN measures urea, a waste product from protein metabolism, while creatinine comes from muscle metabolism and reflects kidney filtration plus muscle mass. When protein intake is inadequate, less protein is broken down to form urea, so BUN decreases. Inadequate protein intake often accompanies reduced muscle mass, which lowers creatinine production and can lead to lower serum creatinine as well. So, both BUN and creatinine levels can drop with insufficient dietary protein. By contrast, adequate protein intake keeps these waste products at typical levels, excess protein tends to raise BUN, and dehydration raises BUN more than creatinine.

BUN measures urea, a waste product from protein metabolism, while creatinine comes from muscle metabolism and reflects kidney filtration plus muscle mass. When protein intake is inadequate, less protein is broken down to form urea, so BUN decreases. Inadequate protein intake often accompanies reduced muscle mass, which lowers creatinine production and can lead to lower serum creatinine as well. So, both BUN and creatinine levels can drop with insufficient dietary protein. By contrast, adequate protein intake keeps these waste products at typical levels, excess protein tends to raise BUN, and dehydration raises BUN more than creatinine.