Which pair correctly represents the normal creatinine ranges by sex?

• A. Male 0.8-1.6 mg/dL; Female 0.6-1.2 mg/dL
• B. Male 0.6-1.2 mg/dL; Female 0.5-1.1 mg/dL
• C. Male 0.4-0.9 mg/dL; Female 0.7-1.3 mg/dL
• D. Male 1.0-2.0 mg/dL; Female 0.4-0.9 mg/dL

Answer: (B)

Creatinine levels reflect kidney filtration and, because men generally have more muscle mass, they typically have higher normal creatinine values than women. A widely used reference range is about 0.6–1.2 mg/dL for men and about 0.5–1.1 mg/dL for women. This pair aligns with those standard ranges, so it’s the best choice. The other sets give values that are either too high or too low for normal and don’t match the expected sex-specific pattern. Keep in mind that individual labs may have slightly different reference intervals, but the general distinction by sex with these ranges is consistent.