In a nutshellDeclining ability to digest lactose is normal after childhood, and some degree of adult intolerance is common in many populations.However, this does not mean that everyone with low lactase levels cannot tolerate any lactose. Most people with LI can tolerate fermented dairy (e.g. cheese, yoghurt). Any dairy avoidance treatment for LI should be individualised, reassessed periodically, and avoid underconsumption of key nutrients such as calcium.