Preventing Bone Loss After Weight-Loss Surgery

Danielle Rosenfeld, MS, RD, LDN, member of the Penn Metabolic and Bariatric Surgery team, discusses bone loss, and how to prevent it while losing weight.

Bariatric surgery can result in excess body weight loss between 40 to 70%. It can also impact bone health, making the need for supplementation vital.

Recent studies are finding that significant and rapid weight loss is associated with increased bone damage. A 10% weight decline has been linked with a measured 1 to 2% bone loss at various sites. Bariatric surgical procedures can further heighten this bone turnover and associated bone loss.

What does this mean? Bariatric surgery patients are at increased risk for osteoporosis and bone fracture. Postmenopausal, lactose intolerant and vegetarian patients may be at even greater risk for osteoporosis. Why significant weight loss impairs bone health is not fully understood and likely involves numerous factors.

Preventing Bone Loss with Calcium and Supplements

Appropriate vitamin/mineral supplementation is essential in preventing bone loss.

Calcium, the most abundant mineral in the body, is stored in the bones and teeth where it supports bone structure by making them strong and dense. After bariatric surgery, calcium absorption is less efficient and supplementation with calcium citrate + vitamin D is essential in order to keep bones strong and healthy. Proper supplementation includes 1500 to 2000 mg daily with no more than 600 mg at a time. Dietary calcium intake is also very important and patients should aim to consume low fat dairy foods and beverages in addition to supplements, up to 3 servings daily.

Taking a complete multivitamin/mineral supplement daily is also required after bariatric surgery as there are many other micronutrients, such as magnesium and vitamin D, which play important roles in bone health. Your surgeon might ask that you take additional vitamin D if your labs indicate you have a deficiency.

A recent study examined bone health at 18 months post gastric bypass surgery and found that there was prolonged bone turnover, which indicates that supplementation needs to be lifelong and not just in the immediate postoperative period.

Bottom Line

• Bariatric surgery patients need to be increasingly aware of bone health and take measures to prevent bone loss associated with rapid weight decline
• Combined dietary and supplemental calcium intake may be required to prevent bone loss during rapid weight loss
• Choose calcium citrate rather than calcium carbonate- this is the form that post-op bariatric patients can absorb
• Consume a diet rich in calcium
• 1 cup milk, 1 cup yogurt, and 2 oz cheese contain at least 300 mg calcium
• 3 oz canned salmon or sardines contain at least 200 mg calcium
• 1/2 cup cooked greens (kale, spinach, collards), ½ cup soybeans, broccoli, white beans contain 50 to 100 mg calcium.

• Follow vitamin/mineral supplementation regimen prescribed by bariatric team