How common is lactose intolerance?

An estimated 30 million to 50 million American adults are lactose intolerant.

The pattern of primary lactose intolerance appears to have a genetic component, and specific populations show high levels of intolerance, including approximately: 95 percent of Asians, 60 percent to 80 percent of African Americans and Ashkenazi Jews, 80 percent to 100 percent of American Indians, and 50 percent to 80 percent of Hispanics.

Lactose intolerance is least common among people of northern European origin, who have a lactose intolerance
prevalence of only about 2 percent.