<qa>  What is the general consensus that the amount of lactose in a glass of milkThere is disagreement amongst researchers regarding the amount of lactose needed to cause symptoms in those who are lactose intolerance. The general consensus is that the amount of lactose in a glass of milk 12 grams is enough to cause mild symptoms in most patients who are lactose intolerant 1. However, there have been a number of studies and case studies that argue that much lower amounts can cause symptoms 2, 3, 4, 5. This could be as little as 0.02 grams 6. 