The Importance of Calcium
钙的重要性
Calcium is a mineral that helps build strong bones and teeth and regulates muscle contraction.
钙是一种物质，有助于坚固骨骼和牙齿，并调节肌肉收缩。
Milk and dairy products have long been held as an important source of calcium.
牛奶和其他乳制品是钙的主要来源。
In addition to calcium, Vitamin D is important because it helps the body absorb and retain calcium in the bones, making them strong.
此外，维生素D也很重要，其主要的功能是帮助人体吸收钙质，不让钙质从骨骼中流失。
Similarly, sufficient exercise is now seen as another vital factor in maintaining healthy bone structure and density.
同样，足够的运动也被视为另一个保持健康骨骼和骨密度的重要因素。
Concerns have been voiced that a lack of exercise in growing children will have a detrimental effect on their bones.
也有担忧表示成长中的儿童缺乏锻炼将对骨骼造成不利影响。
Calcium can continue strengthening your bones until the age of 20 to 25 when peak bone mass is reached.
在20-25岁之前，补充钙质可以促进骨骼的发育。
After this point, your bones can only maintain or lose their density and grow weaker as a natural part of the ageing process.
在这一点上,你的骨骼只能维持或失去骨密度而且随着自然老化过程生越来越脆弱。
Inadequate dietary calcium intake before this age can increase the risk of brittle bone disease,as calcium is drawn from the bones as a reserve.
否则，随着年龄的增长，骨骼会变得越来越脆弱，并引发各种骨骼疾病。