Treatments to Improve Bone Density in Anorexia Nervosa Recovery
One of the most serious and long-lasting medical complications of anorexia nervosa is low bone density. Often silent and without symptoms until a fracture occurs, bone loss in anorexia can lead to osteopenia and osteoporosis, even in adolescents and young adults.
The good news? While bone loss can be difficult to fully reverse, there are proven strategies to improve bone density—especially when addressed early and as part of a comprehensive recovery plan.
In this post, we’ll explore how anorexia nervosa affects bone health, why it's so concerning, and the best available treatments to support skeletal recovery.
How Anorexia Affects Bone Health
Bones are living tissue that constantly remodel themselves. This process requires:
Adequate nutrition (especially calcium, protein, and vitamin D)
Normal hormonal function (estrogen, testosterone, IGF-1, thyroid hormones)
Weight-bearing movement
Stable energy availability
In anorexia nervosa, malnutrition leads to:
Suppressed estrogen and testosterone
Low insulin-like growth factor 1 (IGF-1)
Elevated cortisol, which breaks down bone
Decreased calcium and vitamin D intake or absorption
Amenorrhea (loss of periods), which is strongly associated with bone loss
Reduced bone formation and increased bone resorption
This results in:
Osteopenia in up to 90% of patients
Osteoporosis in 30–50% of those with chronic illness
Increased fracture risk, even with minor falls or in young patients
"The bone damage caused by anorexia during adolescence—when up to 90% of peak bone mass should be developed—can lead to lifelong consequences."
— Misra & Klibanski, Journal of Endocrinology and Metabolism
Can Bone Density Be Restored After Anorexia?
Partial recovery is possible, especially in adolescents and young adults if:
Nutritional rehabilitation begins early
Weight is fully restored and maintained
Menstruation or normal hormonal function resumes
Bone-supportive treatment is started early
However, even after weight restoration, bone density may remain below average—highlighting the need for proactive treatment.
Treatment Approaches to Improve Bone Health in Recovery
1. Nutritional Rehabilitation
This is the foundation for all bone healing:
Weight restoration to a biologically appropriate set point
Adequate calorie intake to support bone remodeling
Sufficient protein for collagen and bone matrix
Calcium intake: 1200–1500 mg/day (food + supplements if needed)
Vitamin D: 600–1000 IU/day (or more if levels are low)
Bone loss will not improve without restoring energy availability, even with medication.
2. Menstrual Resumption
Hypothalamic amenorrhea (loss of menstrual periods due to low energy availability) is a major risk factor for bone loss.
Studies show:
Bone density improves most significantly in patients who resume spontaneous menses
Estrogen from birth control pills does not replace natural estrogen in protecting bones (Misra et al., 2011)
Key Point: Menstruation is a vital sign of bone health—especially in teens.
3. Weight-Bearing Movement (Once Medically Stable)
Low-impact, weight-bearing activities (e.g., walking, gentle strength training) promote bone formation
High-impact or excessive exercise during restriction can worsen bone loss and increase fracture risk
Always consult with a medical team before resuming movement in recovery
4. Medications and Hormonal Support
For those who continue to experience low bone density despite weight restoration, the following medical treatments may be considered:
A. Physiologic Estrogen (Transdermal) in Adolescents
A patch delivering natural (physiologic) estrogen combined with cyclic progesterone
Shown to improve spine and hip bone mineral density in adolescent girls with anorexia
More effective than birth control pills, which suppress IGF-1
Reference: Misra et al., Journal of Bone and Mineral Research (2011)
B. Bisphosphonates (e.g., Alendronate, Risedronate)
Used cautiously in adult women with osteoporosis and no plans for pregnancy
Increase bone mineral density by reducing bone resorption
Not recommended for adolescents or premenopausal women due to long half-life and pregnancy risks
C. Teriparatide (Forteo)
A parathyroid hormone analog that stimulates bone formation
Occasionally used in adults with severe, treatment-resistant osteoporosis
Requires daily injection and close monitoring
D. Recombinant Human IGF-1
May be used experimentally in combination with estrogen in adolescents
Stimulates bone growth but is not widely available or FDA-approved for this use
E. Calcium and Vitamin D Supplementation
Supplement if dietary intake is low
Maintain serum vitamin D levels >30 ng/mL
Monitoring Bone Health
DXA scan (dual-energy X-ray absorptiometry) is the gold standard for assessing bone density
Recommended:
After 6–12 months of amenorrhea
Every 1–2 years in chronic cases
Sooner if there are fractures or risk factors
In adolescents, Z-scores (age-adjusted) are used; a Z-score < –2 is considered “low bone mineral density for age”
Special Considerations for Teens and Young Adults
Adolescents are still building peak bone mass—intervention is urgent
Hormonal suppression during critical growth years may cause irreversible bone deficits
Focus is on early weight restoration, resumption of menses, and nutrient sufficiency
Final Thoughts
Low bone density is one of the most insidious consequences of anorexia nervosa, but also one of the most modifiable—if addressed early and comprehensively.
While medications can help in select cases, nothing replaces the healing power of full nutrition, restored hormonal function, and compassionate care.
Recovery is not just about weight. It’s about strength, structure, and the bones that carry us through life.
References
Misra, M., & Klibanski, A. (2014). Anorexia nervosa and bone. Journal of Endocrinology and Metabolism, 99(7), 2489–2496.
Misra, M., et al. (2011). Physiologic estrogen replacement improves bone density in adolescent girls with anorexia nervosa. Journal of Bone and Mineral Research, 26(10), 2430–2438.
Mehler, P. S., & Andersen, A. E. (2015). Eating Disorders: A Guide to Medical Care and Complications. Johns Hopkins University Press.
Golden, N. H., et al. (2016). Bone health in adolescents with eating disorders. Pediatrics, 138(4), e20160906.
