This is a post which I'm writing more like in a note form, so that I finally am able to publish it.
Hope it is still of help to others too. Please leave your feedback or comments for any other question you think should be answered in this topic or wish to know more. I'll try to include it. Do check the links given at the bottom in this regard. I have tried to keep the list as small as possible and it contains good links to reliable information, which are also the source of information for this post.
Why do children (and adults - to a lesser extent) need calcium?
Required for healthy mental and physical development of the child - by their growing bones and teeth, important for general cellular (body) functioning, especially nerves and muscles, and activating enzymes required by the body to produce energy, and for blood clotting, and many other important body functions.
Long term shortage can lead to rickets among children (osteoporosis among adults-especially 50+).
How much calcium does a child need (a rough estimate)?
Upto 3 years of age: about 500 mg per day calcium - about 1 1/2 - 2 cups milk or plain yoghurt
4 -8 years of age: about 800 mg per day calcium - about 2-3 cups of milk
9-18 years of age: 1,300 mg per day calcium - about 3-4 cups of milk or the equivalent amount of cheese and yoghurt
The calcium in 1 cup of milk = 1 cup of yogurt = 1 and 1/2 ounces of cheese= 2 ounces of processed cheese. 1 ounce = 28 (25-30) g cheese.
For the body to absorb the calcium properly, adequate amounts of Vitamin D is neccsary. A very good source of Vitamin D is the sunlight, which is required by our body to produce vitamin D in our own body.
Good physical activity, like walking, running, jumping, other sports activities which require the legs to carry the body weight, is necessary for children's bones to develop properly and to promote new bone cells to develop and grow.
Food rich in Calcium
Dairy products are supposed to be the best sources of calcium:
Milk, yoghurt and cheese: gouda, chedder, mozarella, ricotta, soft cheese - mould cheese and many others. Cheese is a much more concentrated form of calcium source than milk. Yoghurt is a more easily digestible (proteins) source of calcium than milk. The best option is to include all of them. Cheese also has much lower lactose content than milk or yoghurt, as it has been broken down and used up by microbes present in cheese, which is usually stored for much longer than yoghurt, for example, which is again a better option than milk.
In case of allergies or lactose intolerance or those living on a vegan diet, it can be compensated with many other vegetable sources, beans and fortified products like orange juice fortified with calcium. But in such cases, a doctors advice needs to be taken to see how it can be achieved best.
Calcium rich non-dairy products, some examples:
Soya milk, fortified
Orange juice (packed), fortified
Muesli and cereals, fortified
Green leafy vegetables - like spinach, beet greens and pak choi,
Beans : soya beans- ripe, white beans, baked beans
Crucifers (Brassica spp.): broccoli, brussels sprouts, kale, collard greens, turnip greens, musttard greens, etc.
Other vegetables: Okra
Nuts and seeds: especially sesame seeds, almonds
Grains: amaranth, quinoa
Many common fish varieties, like rainbow trout (cultured), salmon, atlantic sardines
Following is the list of good links to recipes for the above mentioned categories
(I'll update it everytime I find some good information/recipes):
Sources of information for this post (please check the websites below for more detailed answers to the above questions):
Keep kids healthy.com
Children need calcium...
calcium for children and teens
good sources of calcium for my child
Calcium: The vegetarian resource group - Nutrition
Other related posts:
What affects calcium absorption?
Update on 11. Jan 2009:
Just found this very informative page on calcium at Bee and Jai's Jugalbandi: