Osteoporosis in children is rare. It's usually the result of a chronic health condition such as asthma or cystic fibrosis that is treated with corticosteroid medications. Sometimes, children will develop osteoporosis with no clear cause. It's called idiopathic juvenile osteoporosis, and the good news is that it usually goes away on its own within two to four years.
Of course calcium -- the most important nutrient for strong bones -- is important for all children whether they have osteoporosis or not. Even if children are healthy now, low levels of calcium in their diets can greatly increase their risk of osteoporosis later in life. So keep track of how much calcium your children get from food – the first and best option. If they aren't getting enough, supplements may be an option. But never give your child a supplement without talking to your doctor first.