Depot Medroxyprogesterone Acetate (Depo-Provera, DMPA) Effects on Bone Mineral Density: Question Six
Your answer is correct.
Is there anything she can be doing to prevent additional bone loss?
- Option A Encourage non-weight bearing exercise several times per week
- Option B Recommend calcium supplementation if her diet is low in calcium rich foods
- Option C Recommend a low protein diet
What lifestyle measures can be taken to prevent bone loss in adolescents?
Adolescents grow at the greatest rate of any age group and more than 90% of adult bone mineral content is deposited by the end of adolescence. Bone loss generally begins late in the third decade with bone mass declines of approximately 1-2% per year in women. Therefore, adolescence is a time to modify behaviors that encourage bone growth and the following measures are recommended:
- Calcium intake in amounts greater than 1300 mg per day for optimal bone growth. Due to the decrease in milk product consumption in our society over the years, many girls may require supplementation to reach these goals (1).
- Dietary protein intake is essential for the synthesis of bone matrix. Protein is necessary for the production of insulin-like growth factor (IGF)-1, which is vital to the process of bone growth. An ideal diet would include 20% protein, which constitutes approximately 1 gram of protein per kg of body weight (1).
- Vitamins such as magnesium, phosphorus, vitamin D and vitamin K also play a key role (1).
- Avoidance of tobacco use is very important. Studies have shown that long-term exposure to nicotine is associated with lower BMD in heavy tobacco users versus light users (2).
- Moderate, weight-bearing exercise 30 minutes three times per week is associated with increases in bone mineral density. There is a threshold of intensity after which too much exercise can negatively impact bone growth. This is particularly problematic when the exercise is anaerobic or occurs in very thin, amenorrheic girls (1).
Finally, parents should be aware of the risk of eating disorders. In the United States, the prevalence is approximately 1-4%. Of these disorders, anorexia is the most worrisome as more than 50% of women with anorexia have been shown to have bone loss greater than two standard deviations than that of health age matched-controls (3).
- Cromer B. Adolescents: At increased risk for osteoporosis?. Clin Pediatr 2000; 39(10): 565-574.
- Cromer B. Opinions in pediatric and adolescent gynecology: In favor of continued use of depot medroxyprogesterone acetate (DMPA, Depo-Provera) in adolescents. Pediatr Adolesc Gynecol 2005; 18: 183-188.
- Biller BM, Sax V, Gerzog DB, Rosenthal DI and Dlibanski A. Mechanisms of osteoporosis in adult and adolescent women with anorexia nervosa. J of Clin Endocrinol and Metab 1989; 68: 548-554.