Which of the following ranges represents the normal fasting blood glucose range for a non-diabetic adult in mg/dL?

• A. 70 to 99 mg/dL
• B. 60 to 80 mg/dL
• C. 100 to 125 mg/dL
• D. 126 to 140 mg/dL

Answer: (A)

Normal fasting glucose in a healthy adult is about 70–99 mg/dL. Fasting means no caloric intake for roughly 8 hours, allowing the body’s insulin system and liver to maintain blood sugar at a stable, normal level. Values at or above 100 mg/dL after fasting indicate the body isn’t regulating glucose as effectively. Specifically, 100–125 mg/dL is considered impaired fasting glucose (prediabetes), signaling higher diabetes risk, while 126 mg/dL or higher on a single test (confirmed with a second test) indicates diabetes. So the 70–99 mg/dL range is the standard normal reference for non-diabetic adults.