Nutritional aspects of lactose

Lactose appears to promote the absorption of calcium but this is probably due to a nonspecific increase in intestinal osmotic pressure, an effect common to many sugars and other carbohydrates, rather than a specific effect of lactose. 

However, lactose has two major nutritionally undesirable consequences - lactose intolerance and galactosaemia. Lactose intolerance is caused by an insufficiency of intestinal )S-galactosidase - lactose is not completely 

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