Summarize this article in one sentence.
Bones grow fastest early in life and in puberty.  The bones increase in density until they reach peak bone mass.  The denser your child's bones are at peak bone mass, the greater their reserves to protect against osteoporosis later in life.  Serve your child at least five portions of fruits and vegetables per day. (Don't exceed more than one 150ml glass of fruit juice.)  Maintain a daily diet that includes carbohydrates.  Potatoes, pasta, rice and wholegrain bread are examples.  Include protein in your child's diet. Meat, fish, nuts, beans, eggs and seeds work well.  Offer your child plenty of dairy products such as milk and cheese. Calcium makes our bones and teeth hard. Ninety-nine percent of the calcium in our bodies is found in teeth and bone. Vitamin D helps us to absorb calcium.  Insure that your child is getting the recommended intake of calcium. The recommended daily requirement is 1,000 (mg/daily) four to eight year olds. 1,300 (mg/daily) nine to 13 year olds. Your child should focus on getting his required calcium intake past childhood and into young adulthood, as peak bone mass is not generally reached until age 30. The required amount of vitamin D is 600 (IU/daily). Sunlight is our main natural source of vitamin D.  Short, regular periods of exposure to the sun (without sunscreen) are enough to get most people the vitamin D they need. Children with lighter skin should get 10 – 15 minutes of sunlight per day.  Children with darker skin need to spend a little longer in the sun to get the same amount of vitamin D.  Never let your child's skin get red or start to burn. Babies under six months should not be exposed to direct sunlight.

Summary:
Create a bone-friendly diet for your child. Supplement your child's diet with vitamins if necessary. See that your child spends some time in the sun.