Anorexia Nervosa and Bone Health

Protecting bone health 

Bone health is an important part of your general health. When the structure of bone becomes weaker and less dense, there is an increased risk of breaking. This is osteoporosis. It can lead to a higher risk of bone breaking from a minor incident (such as a bump, fall or trip). Early diagnosis and management of osteoporosis can help protect bone health and reduce the risk of breaking a bone

Anorexia nervosa and Bbone health 

The onset of anorexia mainly occurs during the teen years, which is also an important time for bone development and building bone mass (with the peak bone mass normally reached by the mid-twenties). People who have anorexia nervosa (or have suffered from it in the past) are at higher risk of having poor bone health. There are several reasons for this:  

Hormones 

The hormone estrogen is very important for bone growth, particularly in girls undergoing puberty. Low body weight causes the body to stop (or drastically reduce) estrogen production resulting in menstrual periods often stopping. This greatly impacts bone growth and strength. Individuals with anorexia often produce excessive amounts of the hormone cortisol, which is known to trigger bone loss. Levels of other growth-related hormones may also fall because of weight loss during anorexia nervosa, with negative effects on bone health. Low hormone levels (including low testosterone) also affect the bone health of men and boys with anorexia nervosa.  

Low body weight 

Body weight directly affects bone strength, and research has shown that people with very low body weights are at increased risk of osteoporosis. 

Poor nutrition 

Bones require adequate calcium and vitamin D to grow and remain healthy. Protein is also important for muscle health. People with anorexia are unlikely to obtain adequate calcium, vitamin D, protein and other important nutrients from the diet. This can also have a negative impact on bone growth and health. 

Investigating Bone Health 

People with anorexia nervosa should have their bone health investigated and monitored. Your doctor may refer you for a bone density scan to help assess your bone health. As anorexia commonly occurs in younger people, it is important to protect your bone health in the future. Anorexia nervosa can have a  major impact on the ability of the skeleton to achieve its peak bone mass and optimal strength, which can lead to an increase in fracture risk and osteoporosis later in life. This is why it is important to take action to protect bone health for people with anorexia or people with a history of anorexia.

Other common risk factors

Review other common risk factors for osteoporosis. If any risk factors apply to you – discuss these with your doctor.

Personal history

  • Previous fracture (from minor bump or fall)
  • Family history of osteoporosis (parent/sibling)
  • Loss of height (3 cm or more)
  • Smoking/Excessive alcohol
  • Inadequate calcium, vitamin D or lack of exercise
  • Age 70 years and over

Medical conditions

  • Coeliac disease
  • Diabetes
  • Rheumatoid arthritis
  • Early menopause/Low testosterone
  • Chronic kidney disease or liver disease
  • Overactive thyroid or parathyroid

Medications

Calcium, Vitamin D, Exercise

Take simple steps to help support your bone health.

Focus OnRecommended
Calcium• 1,000 mg per day from the diet
• Increasing to 1,300 mg for women over 50 years and men over 70 years
• If dietary intake is low a supplement may be required
Vitamin D• Limited sun exposure – in summer, a few minutes per day, in winter slightly longer
• Avoid UV index above 3
• If vitamin D deficiency is confirmed by your doctor, a supplement may be required
Exercise• Specific mix of weight bearing, resistance training and balance exercises