KARACHI: Peak bone mass can be increased by ensuring that the diet contains adequate amounts of vitamin D and calcium during childhood, adolescence and early adulthood. This was shared by health experts during a public awareness seminar on ‘Love your bones – strong bone’ held in connection with Pak-China Med Cong at Pakistan Medical Association (PMA) House. “By regular activity, especially weight-bearing activities such as walking and climbing stairs (in which the bones bear body weight), can tackle the bone loss issue,” they said. “Bone is a living tissue from which substances are constantly being removed and replaced. Healthy bone is strong and does not break easily. During childhood, adolescence and early adulthood, large amounts of calcium and other substances are added to the bone, strengthening the skeleton as it develops. Bone acts as a reserve for calcium in the body,” said Dr Saeed Minhas. “Bone is continuously remodelled – old bone tissue is replaced by new. Bone formation and bone resorption (replacement of old bone tissue) take place throughout life, although at different rates at different times. In childhood, the process enables the bone to grow; in adulthood the purpose is to maintain bone strength. Bone formation and bone resorption are influenced by a variety of factors including diet and physical activity. Bone formation is greater than bone resorption until the age of 20-35 years, when peak bone mass is reached. After this bone resorption occurs at a faster rate than bone formation,” he observed. He said that strong bones that contain plenty of calcium are less likely to become weak and break in old age. “Bone strength is affected by genetic factors – some ethnic groups may have stronger bones in general than others – men tend to have a greater bone mass than women. Physical activity – regular exercise (especially weight-bearing exercise) is important for strong bones, he said, adding heavier people have stronger bones – the bones respond to the weight that they have to carry,” he explained. “Diet is an important factor in forming healthy bones as an adequate calcium intake at all stages of life. It helps to ensure that bones are as strong as possible. It is particularly important during childhood, adolescence and early adulthood when bones are developing,” he added. He said an adequate intake of calcium is important throughout life. Dairy products such as milk, yogurt and cheese are all good sources of calcium, Dr Saeed Minhas said. He said some foods may provide significant amounts of calcium, but also contain substances that reduce the amount that can be absorbed by the body. People who do not eat dairy products, they should make sure that their diet contains sufficient calcium, he advised. Vitamin D is important for healthy bones because it is needed for the absorption of calcium from food, he said, adding skin develops vitamin D when it is exposed to sunlight. “Most people obtain sufficient vitamin D in this way (particularly in the summer) but some groups, such as people that are housebound or who wear clothes that cover most of their body, need to be sure that their diets contain enough vitamin D. When the vitamin D production in our skin is insufficient, we have to rely on food sources. Good sources are oily fish, eggs, butter, meat and margarines fortified with vitamin D, he concluded.