Nutrition, Bones & Osteoporosis

The first thing that would come to mind when thinking about diet and bone health is Calcium.  Now, this is definitely true as Calcium is an essential mineral for bone health, but there are also a number of other dietary factors that need to be considered. Let us start with the basics…


Calcium is an essential mineral that is involved in building and maintaining healthy bones. It combines with other minerals to form the hard crystals that give bone its strength. Almost all the body’s calcium is found in bones so you can consider them as being a calcium bone bank. When the calcium concentration in body fluids falls too low and your diet is low in calcium, it is drawn out of the bones. A diet low in calcium means we are constantly drawing on the bones where calcium is being released from bone into the blood stream, subsequently resulting in calcium loss and weakening the bones.

 How much calcium do I need and where do I get it from?

Guidelines have been set to help people ensure that they are getting enough calcium from their diet. A guide which is based on Australian guidelines for how much calcium every age group requires is provided in the table below:

Since calcium is not made by our bodies, it is essential to obtain it from food. The following are good dietary sources of calcium:

  • Dairy Products – milk, yoghurt, cheese and buttermilk. One cup of milk, a 200g tub of yoghurt or 200ml of calcium fortified soymilk provides around 300mg calcium. Also, low fat dairy products will not have less calcium than their full fat counterparts. However, low fat products are not suitable for children under the age of 2.
  • Soy and tofu – tofu (depending on type) or tempeh and calcium fortified soy drinks.
  • Fish – sardines and salmon (with bones).
  • Green leafy  vegetables – broccoli, collards (cabbage family), bok choy, Chinese cabbage and spinach. One cup of cooked spinach contains 100mg, although only five per cent of this may be absorbed. This is due to the high concentration of oxalate, a compound in spinach that reduces calcium absorption.
  • Nuts and seeds – brazil nuts, almonds and sesame seed paste (tahini).
  • Calcium enriched foods – including breakfast cereals, fruit juices and bread

What can affect calcium absorption?

Apart from ensuring that you are getting enough calcium, you need to be aware that there are some factors that affect calcium absorption and may cause calcium loss from bone:

  • High salt diet
  • High caffeine intake i.e. 5-6 drinks per day of caffeine-containing  such as coffee, cola and tea (although tea has less caffeine)
  • Excessive alcohol intake
  • Very high intakes of fibre (more than 50g per day, from wheat bran)
  • Poor activity levels
  • Low levels of vitamin D – Vitamin D is needed for your body to absorb calcium properly. People who are housebound or cover their bodies completely when they are outside are at increased risk. The body produces vitamin D naturally when skin is exposed to sunlight. Exposure of hands and face for 10 minutes a day or 1 hour per week is thought to provide sufficient Vitamin D.
  • Smoking – which may be related to nicotine’s toxic effect on bones.

What happens if I don’t get enough calcium?

One of the biggest consequences of having a poor calcium intake over a long period of time is having weak and brittle bones which can eventually lead to osteoporosis. Osteoporosis is a condition that develops when bones lose calcium, become fragile and tend to fracture more easily. In order to get the picture, you need to be aware of how bones are structured. Bones are made up of a hard outer shell covering a less dense tissue which looks like honeycomb. When osteoporosis develops, the outer shell becomes thin and fragile, and the honeycomb-like tissue develops larger holes. The bones weaken and can fracture more easily. Osteoporosis is diagnosed by a scan which tests your bone density (strength) and this test is called a DXA scan (Dual-energy X-ray Absorptiometry). Before going for a test, your doctor will assess your risk factors for osteoporosis by looking at your age, medical history and lifestyle.

People who are risk of developing osteoporosis are usually placed on calcium supplements if their overall dietary consumption of calcium is poor. Before taking a supplement, always check with your doctor first.

 Bottom line is…

Think in terms of the following to make sure you keep your bones healthy:

  • Am I getting enough calcium from food? If not, do I need a supplement? Make sure that you include a good variety of foods high in calcium on a daily basis. If you are finding it difficult, then you can always consult a dietitian to provide you some guidance. Before taking any supplement, consult your doctor.
  • Am I getting enough vitamin D? 10-15 minutes in the sun everyday can help boost your vitamin D levels. To check for a vitamin D deficiency, your doctor will usually send you for a blood test.
  • Am I exercising regularly? Bone strength also relies on weight-bearing exercise. Bones are like muscles where making them work stimulates their development. Weight-bearing exercises create a positive stress on bones and they include activities like walking, jogging, tennis, squash or dancing. Even if you have osteoporosis, there are many benefits of being active and they include preventing further bone loss. Also, by improving your balance, flexibility and co-ordination, you can reduce your risk of falls and injuries.

  1. When depicting exercise routines for osteoporosis, you need to include power and resistance training, plus some good balance routines.

  2. Thanks for the blog.Much thanks again. Want more.

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