Osteoporosis (thinning of the bones to the point of brittleness) and osteopenia (decreased bone mass and a precursor to osteoporosis) are newer complications faced by adolescents and adults with CF. Osteoporosis is a disease of the skeleton, resulting in lower bone mass and a reduced bone density. All patients with CF are at risk of osteoporosis, especially those with more severe disease and those with low body weight.

The consequences of this disease are that bones become fragile and are more likely to break. If not prevented or if left untreated, osteoporosis can progress painlessly until a bone breaks. Most bone mineral content (which makes bones strong) is produced by the body in the first twenty to thirty years of life. It is important in these years to ensure that an adequate calcium and vitamin D intake is met. Calcium is the key mineral in maintaining bone density. However, intake of calcium alone is not enough, since vitamin D levels in the body directly affect calcium’s absorption. Because vitamin D is a fat-soluble vitamin, persons with CF often have trouble absorbing this vitamin and thus don’t absorb enough calcium. There are many other risk factors that influence the onset of osteoporosis including poor nutrition in childhood, chronic infections, delayed puberty, diabetes, reduced exercise or weight bearing activities, and treatment with corticosteroids (which can lead to calcium loss).