Good bone health results from a proper balance between the two ongoing processes of bone deconstruction and reconstruction. These processes depend not only on calcium levels in the body, but also on physical activity that stimulates bonebuilding; hormones and other controlling signals; trace nutrients (including vitamin C, magnesium, potassium, and zinc); and other as yet unidentified substances.
There appear to be factors in tea and in onions and parsley that slow bone deconstruction significantly. Vitamin D is essential for the efficient absorption of calcium from our foods, and also influences bone building. It’s added to milk, and other sources include eggs, fish and shellfish, and our own skin, where ultraviolet light from the sun activates a precursor molecule.
The amount of calcium we have available for bone building is importantly affected by how much we excrete in our urine. The more we lose, the more we have to take in from our foods. Various aspects of modern eating increase calcium excretion and so boost our calcium requirement.
A high intake of salt is one, and another is a high intake of animal protein, the metabolism of whose sulfurcontaining amino acids acidifies our urine, and pulls neutralizing calcium salts from bone. The best insurance against osteoporosis appears to be frequent exercise of the bones that we want to keep strong, and a well-rounded diet that is rich in vitamins and minerals, moderate in salt and meat, and includes a variety of calciumcontaining foods.
Milk is certainly a valuable one, but so are dried beans, nuts, corn tortillas and tofu (both processed with calcium salts), and several greens — kale, collards, mustard greens.