My son is 10 & 1/2 yrs old, 4'11" tall, and weighs 98 lbs. He has an incredibly healthy diet as I make sure he gets plenty of fresh fruits, veggies, milk, and meals with little or no trans fats daily. He eats barely any candy, soda, or fast foods. He is very active, loves to run, and has been studying aikido for a year now. In the last three months or so, he has brought to my attention the fact that his knees crack (or click). Is this normal for a kid like him and how safe are supplements like glucosamine, chondritan, and msm as I (48 yrs) have used them with astonishing results?
There is no reason to be concerned about his knees making noise as this is a function, in children, of their loose ligaments and do not need treatment or cause pain. Also, as long as he is eating healthy as you say he is then he doesn't even need a vitamin supplement. The glucosamine etc., which I use too, is for degenerating joints, not "generating" ones and would not be of value. No one knows the long term consequences of these OTC meds and I certainly wouldn't advise using in a child.
33 years of experience as a general pediatrician in private practice and in pediatric urgent care.