A U.S. National Institutes of Health draft consensus statement released a suggestion that most people who think they are lactose 
Lactose intolerance is a condition wherein the sugar lactose in dairy products is not broken down by the body, thereby causing a range of discomforting symptoms in individuals. Therefore, the immediate reaction to a suspected case of lactose intolerance is to go off milk and other dairy products. Sadly though, this deprives individuals of essential nutrients that come from dairy products such as milk and yogurt, particularly calcium and vitamin D.
“Particularly in children and adolescents, it’s very difficult for them to receive enough calcium and vitamin D if they avoid diary completely. The same thing may hold true for adults,” said Dr. Frederick J. Suchy, chairman of the conference preceding the statement and professor and chief of paediatric hepatology at Mount Sinai School of Medicine in New York City. “Vitamin D and calcium have important effects, for certain for bone health, and may have implications in other areas such as cardiovascular health, hypertension and maybe even colon cancer,” he said.
An enzyme called ‘lactase’ present in the small intestine digests lactose. Babies have an abundance of this enzyme and are therefore able to digest milk effortlessly while breast-feeding. However, in most individuals, the body is programmed to reduce lactase production post weaning and gradually over childhood. Exceptions to this are people that are largely from northern European descent who have retained lactase and have the ability to ingest and process lactose later in life, perhaps due to their history of raising cows and consuming dairy products.
Lactose intolerance is manifested as diarrhoea, abdominal pain, and flatulence and bloating. Doctors need to first rule out presence of more serious medical conditions such as celiac disease or irritable bowel syndrome. Further, one needs to check if abstaining from the consumption of diary products is proving any relief. In serious cases, patients are taken off diary products completely and are given nutritional supplements to make up for the deficit. However, in milder cases, alternative strategies like taking small amounts of milk throughout the day or with meals or including yogurt and hard cheeses, especially low-fat hard cheeses, in the diet might be tolerable.
“This is not an allergic condition where if you take a little bit of milk you get sick. That’s quite rare,” noted Dr. Marshall A. Wolf, a panel member and professor of medicine at Harvard Medical School in Boston. “This is a quantitative condition and most people, even those with malabsorption, can take a certain amount of milk products without any symptoms, and there is some evidence to suggest that if you take milk products on a regular basis, you can build up your tolerance for milk.”
Solid estimates of the prevalence of lactose intolerance are lacking, because medical studies have different interpretations of the condition, the experts write in their concluding statement.