From Dr. Fuhrman's book Eat to Live:
Green Vegetables, beans, tofu, sesame seeds, and even oranges contain lots of usable calcium, without the problems associated with dairy. Keep in mind that you retain the calcium better and just do not need as much when you don't consume a diet heavy in animal products and sodium, sugar, and caffeine.
Many green vegetables have calcium-absorption rates of over 50 percent, compared with about 32 percent for milk.1 Additionally, since animal protein induces calcium excretion in urine, the calcium retention from vegetables is higher. All green vegetables are high in calcium.
The American "chicken and pasta" diet style is significantly low in calcium, so adding dairy as a calcium source to this mineral-poor diet makes superficial sense---it is certainly better than no calcium in the diet. However, much more than just calcium is missing. The only reason cow's milk is considered such an important source of calcium, is that the American diet is centered on animal foods, refined grains, and sugar, all of which are devoid of calcium. Any healthy diet containing a reasonable amount of unrefined plant foods will have sufficient calcium without milk. Fruits and vegetables strengthen bones. Researchers have found that those who eat the most fruits and vegetables have denser bones.2 These researchers concluded that not only are fruits and vegetables rich in potassium, magnesium, calcium, and other nutrients essential for bone health, but, because they are alkaline, not acid-producing, they do not induce urinary calcium loss. Green vegetables in particular, have a powerful effect on reducing hip fractures, for they are rich not only in calcium but in other nutrients, such as vitamin K, which is crucial for bone health.3
1. Weaver, C.M., and K. L. Plawecki. 1994. Dietary calcium: adequacy of a vegetarian diet. AM. J. Clin. Nutr. 59 (supp.): 1238-41S.
2. Tucker, K. L., M. T. Hannan, H. Chen, et al. 1999. Potassium, magnesium, and fruit and vegetable intake are associated with greater mineral density in elderly men and women. Am. J. Clin. Nutr. 69 (4): 727-36; New, S. A., S. P. Robins, M.K. Campbell, et al. 2000. Dietary influences on bone mass and bone metabolism: further evidence of a positive link between fruit and vegetable consumption and bone health? Am. J. Clin. Nutr. 71 (1):142-51.
3. Feskanich, D., P. Weber, W.C. Willett, et al. 1999. Vitamin K intake and hip fractures in women: a prospective study. Am. J. Clin. Nutr. 69 (1):74-79.