Bone is what makes up our skeleton and gives structure to our bodies. Bone is a living growing tissue and has three major components. These are:-

  • Collagen – this protein gives bones a flexible framework
  • Calcium-phosphate mineral complexes – these minerals make bones hard and strong
  • Bone cells – these cells are involved in the process of regeneration of bone, by removing and replacing weakened sections of bone

The skeleton is made up of 206 bones. In the womb and for about the first five weeks of our lives  our bones are mainly cartilage, and are softer and more flexible. Thereafter, the process of ossification takes place where calcium is increasingly laid down as a child grows and matures, and the bones grow harder and stronger.

Bones will continue to get denser until each individual reaches peak bone mass, and this usually occurs between the ages of 18 and 25.

The years before peak bone mass are important, because the amount of bone mass you lay down in the period leading up to this, can influence the strength of your bones as you grow older and your propensity for developing osteoporosis later in life.

So prior to peak bone mass we form bone faster than we lose it, but from this point on we lose more bone than we form. While not the only factor, the rate at which we lose bone mass can be influenced by our lifestyles.

Osteoporosis is a common bone disease that is characterised by losing too much bone, not making enough new bone or both. This produces weaker bones, whose internal structure starts to resemble honeycomb.

It is most common in post-menopausal women, when a sudden drop in oestrogen levels affects bone regeneration, but does affect men too. Most people are unaware they have it until they have a fall or accident.

There are a number of diseases and conditions that can increase bone loss. These include:-

  • Auto-immune diseases – rheumatoid arthritis, lupus, multiple sclerosis and ankylosing spondylitis (spinal arthritis)
  • Digestive and gastrointestinal disorders – coeliac disease, Crohn’s Disease and ulcerative colitis
  • Endocrine and hormonal disorders – diabetes, hyperparathyroidism, hyperthyroidism, Cushing’s syndrome, thyrotoxicosis, irregular menstruation, premature menopause and low testosterone and oestrogen levels in men
  • Haematologic and blood disorders – leukemia, lymphoma, multiple myeloma, sickle cell disorder, blood and bone marrow disorders and thalassemia
  • Neurological and nervous system disorders – stroke, Parkinson’s disease, multiple scleroris and spinal cord injuries
  • Mental illnesses – depression and eating disorders
  • Cancers – breast and prostate
  • Other diseases – AIDS/HIV, chronic obstructive pulmonary disease, female athlete triad, kidney and liver disease, organ transplants, polio, poor nutrition, scoliosis and extreme weight loss

If you are affected by any of these diseases or conditions, you should seek the advice of your doctor to discuss how you can minimise the effect of your condition on your bone health.

There are many medicines that can accelerate bone loss outside the natural aging process.  This is likely to occur only through long term use though. Glucocorticoids or corticosteroids are steroids and are examples of drugs that can adversely affect bone health. There are too many other medications to list, but if you are taking medications long term, then you should make yourself aware of any potential side effects and discuss these with your doctor if you have concerns.

How to optimise bone health

There are two nutrients that are crucial for bone health. These are calcium and vitamin D.

Calcium’s is used as the main building material for teeth and bones. For those at risk, particularly for those who don’t eat dairy, supplementing with calcium can be used to prevent osteoporosis. RDA is 800mg.

Vitamin D is actually a group of vitamins, which some don’t actually consider as a vitamin. Vitamin D has many functions, but it is crucial for enhancing the absorption of calcium. Therefore, adequate amounts of both are required to build and maintain healthy bone. 

The most important compounds of the D group are D₃ (cholecalciferol) and D₂ (ergocalciferol). Very few foods contain vitamin D, particularly D₃, which is mainly synthesised in the skin when it is exposed to the sun (or UVB radiation).

For those of us living in the northern hemisphere, especially during the winter, I would recommend supplementing with a good quality D₃ supplement. RDA is 5µg.

Phosphorus is also important, so ensure you get enough in your diet.

Foods rich in calcium, vitamin D and phosphorus:-

  • Calcium – Milk and dairy products. Some vegetable sources include calcium, but absorption rates can be much lower from these sources. They include leafy green vegetables, oranges and figs. Calcium can also be obtained from sesame seeds, almonds and beans
  • Vitamin D - Fortified dairy products, eggs, liver and oily fish. Sunlight.
  • Phosphorus - Meat, poultry, fish and dairy

The final piece of the jigsaw in optimising bone health is exercise, particularly loaded exercise. Just as resistance exercise stresses muscle and in the right circumstances builds it, resistance exercise does the same with bone. Strength athletes will have much higher bone masses than the general population.

However, even walking is load bearing exercise and provides a host of other benefits too, so ensure you are taking regular exercise and getting enough calcium and vitamin D in your diet to keep your bones healthy.

Published by Neil Elbourne