Lactose intolerance is the inability to digest significant amounts of lactose, the natural sugar found in dairy products, due to an inadequate amount of the enzyme lactase. Undigested lactose can lead to abdominal pain and cramps, bloating, flatulence, and diarrhea. Many people with real or perceived lactose intolerance restrict dairy consumption and do not consume enough calcium and vitamin D. Inadequate calcium intake during adolescence is especially concerning because maximal bone mineral accretion takes place during this stage of life. Inadequate bone mineralization may increase the risk of osteoporosis and bone fracture in later life.
For these reasons, NICHD scientists are seeking to better understand the normal growth and development of bone in youth; to clarify the effect of inadequate calcium intake attributable to lactose intolerance on bone growth; and to identify genetic, behavioral, and dietary factors that promote bone mineral accretion during childhood and adolescence.