In women, the rate of bone loss increases temporarily, around the time of the menopause . This is because bone formation and loss is influenced by hormones. The mineral calcium is obtained from the diet and deposited in bones and teeth. It is particularly important during childhood, adolescence and early adulthood when bones are developing. Vitamin D is also important for healthy bones because it is needed for the absorption of calcium from food.
Vitamin D is made in skin that is exposed to sunlight.
D. Few foods contain large quantities of vitamin D. Fish liver oils have very high levels and oily fish, eg sardines and tuna, are also rich sources. Egg yolk, liver and butter contain smaller amounts of vitamin D. Margarine is fortified by law with vitamin D, and many low fat spreads and some breakfast cereals are also fortified. Rickets affects the structure of the growing bone. The bones lack calcium and are weak. The weight of the body causes the bones of the legs to become bent.