Diet should be centered on vegetables, dark green leafs and plant proteins, remembering that HIGH protein diets can encourage the elimination of calcium and although most of us eat more than recommended, 4oz day is sufficient per day.
It is also believed that phytoestrogens: soy, beans, flax, and sesame also assist with the absorption of calcium, and eating brassicas vegetables: Kelp, leafy greens like: dandelion, nettles, kale, the three chards, Chinese cabbage, bok choy, kale nettle, dandelion, broccoli, brussel sprouts and seaweeds.
There has been some recent information stating that Spinach INHIBITS CALCIUM absorption in the bones, and caffeine, soda, smoking and alcohol REDUCE calcium absorption and can encourage the breakdown of bone.
Calcium intake is recommended at 100-1200 mg day and it is a plus to choose a supplement that includes vitamin D and possible magnesium.
Fish bone broth, fatty salmon and sardines increases minerals in the body, but dairy, although high in calcium is hard for the body to digest and absorb.
If you are challenged with natural sources of calcium and vitamin D you can look to fortified foods like alternative milk products (Almond, hemp, coconut, etc.), orange juice and tofu.
Weight bearing exercises promote building of bones density.