As we age, our bones often lose calcium and so become less dense and therefore more vulnerable to fracturing. Women who have had one or more children are at particularly high risk of osteoporosis (thinning bones) because calcium deficiency during pregnancy will mean that the growing child will absorb the calcium it needs from its mother’s body. So a daily intake of sufficient milk is important in order to provide the body with the calcium it needs and prevent osteoporosis. People with milk allergies can consume calcium tablets, but absorption of calcium from such tablets is much lower than absorption from milk. For those who can’t tolerate cow’s milk, the milk from sheep (if available) is an excellent substitute.
Almost as important as calcium is the hormone calcitonin. Calcitonin helps prevent osteoporosis (low bone density) by inhibiting the body's bone-absorbing osteoclasts and simultaneously promoting the uptake of new calcium into the bones. As people age, their calcitonin levels drop and few if any physicians test for this hormone, so it may be necessary to “shop around” in order to find a physician who can arrange for the necessary blood panel.
In addition to drinking milk and ensuring proper levels of calcitonin in the body, weight-bearing exercise is also essential for maintaining proper bone density. This is because the body reduces calcium where it seems not to be needed. So if a person is not stressing their skeleton by means of regular weight-bearing exercise, the body will act as if it doesn’t need all that bone. Aerobic exercises like running, tennis, and other non-weight bearing exercises won’t help the body to maintain bone density and in fact runners are often at elevated risk of osteoporosis because their bodies try to reduce mass as much as possible in order to limit overall metabolic stress during long runs.