Lactase is the digestive enzyme necessary for absorption of the carbohydrate lactose (milk sugar). In some racial groups, lactase activity is high at birth but declines to low levels by adulthood. These people are lactose intolerant and have abdominal pain, bloating, and flatulence when milk products are consumed. Millions of American adults have the potential for lactose-intolerance symptoms, and traditional estimated rates were that 15% of whites, 50% of Mexican Americans, and 80% of African Americans had the condition. Yet a recent study found the prevalence rates in practical life settings is significantly lower than previously estimated rates.36 When subjects were screened for symptoms following a typical serving of dairy food in the home setting, lactose-intolerance prevalence estimates were 7.72% for whites, 19.5% for African Americans, and 10% for Hispanics.36 This is clinically significant because dairy foods meet crucial nutritional requirements including calcium, magnesium, and potassium. If people perceive themselves to be lactose intolerant based on racial heritage, the lowered calcium intake may affect bone health. Health care providers should encourage low-fat or fat-free daily foods and monitor any symptoms.