By: Stacey B. Schulman, MS, RD, CDN, Registered Dietitian

What is Osteoporosis?  

Osteoporosis is the weakening of bone tissue caused by a lack of mineral content that makes a person more susceptible to fractures. Although often seen as a disease among elderly woman, osteoporosis affects young woman and men with eating disorders due to the malnutrition and hormonal problems that accompany the disorder. Osteoporosis is often described as a disease that develops in childhood and presents itself in adulthood. Bone mineral mass production increases during childhood and adolescence. The peak bone mass is reached by age 15; however, a small amount is produced until age 30, after which we begin losing our bone mass. Due to the disease process, nutritionists are faced with a greater challenge when working with a young client with an eating disorder as the chance of them reaching their peak bone mass is diminished. To further complicate matters, bone loss can be accelerated at any age by excessive exercise or weight loss.

Deficiency in calcium is often associated with osteoporosis. If the diet is deficient in calcium, the calcium is stripped from the bone to fulfill the body’s immediate needs. In addition, in order for the body to correctly process calcium, adequate amounts of protein and calories are necessary. Vitamin D is needed to absorb the calcium—while we can make vitamin D from sunlight, most of us to do not get adequate amounts. Vitamin D is a fat-soluble vitamin and therefore needs fat in the diet in order to be absorbed. Calcium, vitamin D, protein and calories are often inadequate in those with eating disorders.

There is a dynamic balance between bone formation and bone resorption, but when there is inadequate nutrition and hormonal fluctuations this balance can be upset. Low body weight in females causes the body to stop producing estrogen, which results in amenorrhea and significant loss in bone density. In males, the decrease in testosterone production can cause the loss of bone.

Diagnosing Osteoporosis  

A blood test to assess estrogen or testosterone levels is an appropriate starting point for diagnosing osteoporosis, but it is insufficient in assessing how much bone has been lost.

X-ray tests are an objective measurement tool that can clearly assess bone loss. Dual energy x-ray absorptiometry, or DEXA, is used to measure bone mineral density, usually of the lower spine and hip. Follow-up scans should be performed to reassess the progress of the disease and response to treatment.

Treatment

Weight restoration, normalizing body composition, and adequate amounts of calcium and vitamin D are the keys to managing osteoporosis in those with eating disorders.

Calcium intake needs to be at 1500 mg per day—more often then not there will need to be a supplement involved. As a nutritionist, working with clients to increase their calcium intake to optimal levels is challenging and often requires time and patience—since time is of the essence with osteoporosis, a supplement will allow us to treat the osteoporosis as calcium in the diet is slowly increased. Calcium supplements can only be absorbed 500 mg at a time; therefore, supplements need to be spaced accordingly.

The current recommendation for vitamin D is 400 IU (international units) but this is currently under review—the thought is the body requires more than the recommendation. Treatment should include supplementation; finding a calcium supplement with vitamin D is ideal.

Once the weight has been restored, moderate exercise such as walking or yoga and strength training may be helpful in treatment. A nutritionist should monitor exercise closely so that it does not become obsessive or result in weight loss.

Conclusion