How does calcium affect bone development and strength?

How many times growing up do you recall your mum telling you to eat your dairy in order to have strong bones. Well guess what, she was right. Dairy products contain calcium, which is a crucial mineral in promoting bone development and strength.

So how does calcium affect bone development and strength?

Human bone is a dynamic tissue, which means that it responds to stress, inactivity, hormonal changes, as well diet by forming or losing tissue, Bones continuously undergo cycle of destruction and renewal, with this changes being reflected in the bone mineral density (BMD). An individual is in a state of positive bone renewal balance until peak bone mass is achieved in early adulthood. As we get older, bone regeneration process becomes less efficient and small deficits start to occur at the end of each bone regeneration cycle. Generally, as we mature these accumulated deficits will result in an age related decline on bone mass, which can lead to osteoporosis or osteopenia. The two main factors that play a major role in improving bone regeneration process are amount of exercise and level of calcium.

Physical impact and weight baring exercises help to stimulate bone formation, since as muscle gets stronger and bigger, bone consequently become stronger and denser. The best bone builders are exercises that put force on the bone such as weight-bearing, like running or resistance training.

Moreover, being physically active has been shown to improve co-ordination and balance, which helps to prevent falls. However, one must remember that any positive gains in bone strength are lost when you stop exercising for long periods of time; as a result it is important that your exercise is regular an ongoing.

Calcium combined with other minerals form hard crystals that give bone its strength, with almost 99% of body’s calcium found in the bones with the remaining 1 % dissolved in bodily fluids. Calcium plays many varied roles in the body; it regulates muscle function, helps normal clotting of blood, regulates some hormone secretions, helps to control the stimulation of nerves, and activates some enzymes. When you are not getting sufficient amounts of calcium in your diet, some of the calcium crystals dissolve into the bloodstream, in order to maintain normal bodily functions. Consequently, bones act as calcium storage, storing calcium and releasing it when needed into the bloodstream.

Unfortunately, our bodies can not naturally produce calcium; therefore it is essential that the adequate supply of calcium comes from a well balanced diet. Otherwise if your calcium intake is too low as result you are at risk of losing bone density and bone strength.

For most people dairy foods are the major and most convenient source of calcium, but small amounts of calcium are found in nuts, breads, cereals, fruits and vegetables. Research shows that three servings of dairy products each day will generally provide average person with the recommended level of calcium intake for the day.

The table below specifies different amount of daily calcium intake required for different age groups:

Recommended daily calcium intake
Category

Age (years)

Calcium (mg)

Children

1-3

500

4-8

700

 Girls

9-11

1000

12-18

1300

Women

19-50

1000

>50

1300

Pregnancy/Lactation:

14-18

1300

19-30

1000

31-50

 1000

Boys

9-11

 1000

12-18

1300

Men

19-70

1000

>70

1300

Source:2National Health and Medical Research Council. (2006) Executive Summary of Nutrient Reference Values for Australia and New Zealand Including Recommended Dietary Intakes. Commonwealth Department of Health and Aging, Australia, Ministry of Health, New Zealand.