Earlier this month it was National Healthy Bones Week in Australia (1-7th August 2010). I have spent a fair bit of time this month visiting an elderly relative in hospital who is suffering from osteoporotic fractures and their many complications. These injuries cannot be underestimated, they are absolutely devastating and life threatening in the elderly.

What is calcium?

Calcium is a mineral which is essential for healthy bones and teeth. It also plays a crucial role in other body functions such as heart and nerve function. A good intake of calcium has been shown to prevent high blood pressure, PMS and kidney stones, and research is also showing that it plays an important role in weight management.

What causes osteoporosis?

Calcium is used in the body each day (it is used to make your heart beat) and if you don’t eat enough to replace what is used, calcium is drawn out of the bones to be used in essential body functions such as heart function. If this continues over a period of time, it can weaken bones, and can lead to osteoporosis and stunted growth in children and adolescents.  Bone is constantly being broken down and replaced by the body – exercise is as essential to making new bone as the nutrients (calcium, vitamin D etc). Some common medications can also reduce bone density.

Which foods contain calcium?

Calcium is found in a variety of foods but the major source of calcium in the diet for most Australians is milk and dairy foods such as yoghurt and cheese. Calcium-fortified soy milk, tofu, canned salmon and sardines (including the soft edible bones), almonds, brazil nuts, dried figs, parsley, sesame seeds and unhulled tahini are great alternative sources of calcium. Leafy green vegetables such as kale, collard greens, bok choy, Chinese cabbage and broccoli also contain a significant amount of calcium.

What else effects calcium?

It is not just the amount of calcium you consume that is important, but how well it is absorbed and retained in the body. Vitamin D is essential for calcium absorption and for most people this can be obtained by getting around 15 minutes of sun exposure a few times a week (early morning or late in the day, avoiding the midday sun). Vitamin D can also be obtained from the diet and is found in cod-liver oil, oily fish and eggs.

It is important to be aware that a diet high in salt can reduce calcium absorption as can caffeine and carbonated drinks, particularly cola drinks.

Do I need to exercise to have strong bones?

Yes, participate in regular weight-bearing activity will help you to maintain healthy bones (eg brisk walking, tennis, netball or soccer and resistance training exercise (lifting weights).