Protecting Your Bones: A Crucial Aspect of Metabolic and Bariatric Surgery

Protecting Your Bones: A Crucial Aspect of Metabolic and Bariatric Surgery - Bariatric Fusion

Guest Blog By: Dr. Lillian Craggs-Dino, DHA, RDN, LDN

Metabolic and bariatric surgery is a life-changing journey that empowers individuals to reclaim their health and reshape their future. It serves as a powerful tool for those battling with severe obesity, aiding in the management of obesity-related comorbidities and supporting overall well-being. 

However, it’s essential to acknowledge that metabolic and bariatric surgery comes with specific nutritional risks, including the potential development of a metabolic bone condition known as osteoporosis

While not everyone undergoing metabolic and bariatric surgery will develop osteoporosis, the surgery does increase the risk. This highlights the crucial need to follow the American Society for Metabolic and Bariatric Surgery (ASMBS) nutritional and clinical practice guidelines, encompassing adequate protein intake, vitamins, and minerals through supplementation to support health.*

Understanding Metabolic Bone Disease

Metabolic bone disease is a broad term encompassing various conditions that affect bone health. One of the most prevalent and concerning among them is osteoporosis, or a loss in bone mineral density (BMD). It causes bone loss by disrupting the balance between bone formation and bone resorption, leading to a gradual loss of bone mineral density.

Osteoporosis is called the “silent disease” because it typically progresses without noticeable symptoms until it reaches an advanced stage. Once it has progressed, there is an increased risk of osteoporotic fractures, bone pain, low bone mass, and muscle weakness. 

The human skeleton is a dynamic structure, constantly undergoing a process of bone remodeling or bone metabolism, which involves bone formation and the removal of old or damaged bone tissue. To maintain bone health, the body relies on a delicate balance of essential nutrients, including calcium, vitamin D, vitamin K, protein, phosphorus, iron, and others. This complex interaction ensures that bones remain strong, dense, and capable of withstanding the rigors of everyday living. 

The Metabolic and Bariatric Surgery Connection

Metabolic and bariatric procedures, while incredibly effective in achieving weight loss and improved metabolic health, can disrupt the delicate balance of essential nutrients.

The surgery alters the digestive system, increasing the incidence of micronutrient deficiencies due to nutrient malabsorption and lower nutrient intake resulting from smaller meals. These deficiencies can encompass critical nutrients for maintaining bone health and other vital body functions. 

Understanding Nutritional Deficiencies

Understanding nutritional deficiencies is important for maintaining optimal health and well-being. Our bodies rely on many vitamins, minerals, proteins, and other nutrients to carry out vital processes, from energy production to immune system function to bone health.

Many people believe that nutritional deficiencies are only caused by the gastrointestinal changes made during surgery, which can lead to nutrient malabsorption and lower nutrient intake for the outcome of weight loss. However, many don’t realize they may already have a nutritional disadvantage before surgery.

1. Vitamin D deficiency: Research shows that most preoperative metabolic and bariatric surgery patients already have insufficient vitamin D levels, even before surgery. (1) Vitamin D is essential for calcium absorption, a cornerstone for bone health.

2. Calcium insufficiency: Calcium, another vital player in bone health, is also at risk after metabolic and bariatric surgery. Reduced stomach capacity, changes to the intestinal tract, and dietary adjustments can lead to inadequate calcium intake and absorption. (2)

3. Protein intake: Surgery is followed by a significant reduction in food intake, including protein. This can lead to inadequate protein intake, impairing the body’s ability to build and repair bone tissue and compromising overall bone strength. (3)

These deficiencies can significantly affect bone health and overall well-being. Pre-surgical evaluation, nutritional counseling, and ongoing monitoring are essential for successful patient outcomes. 

Other Risk Factors That Influence Bone Health 

Apart from surgical factors and nutritional aspects, several other factors play a pivotal role in influencing bone health. These factors encompass genetics, physical activity levels, hormonal balance, and dietary choices.

Excessive Sodium 

Sodium can leach calcium from bones, which significantly impacts bone health and should be managed cautiously. The American Heart Association recommends that adults consume no more than 2,300 milligrams (mg) of sodium daily or 1,500 mg if you have high blood pressure, also known as hypertension. (4)

Caffeine Intake

Caffeine can interfere with vitamin D and calcium absorption, causing adverse effects on bone density and strength. The Food and Drug Administration (FDA) defines excessive caffeine intake as more than 400 mg per day. (5,6)

Recognizing these external risk factors and making informed dietary and lifestyle choices supports the protection and preservation of bone health.

Supporting Bone Health*

Supporting bone health after metabolic and bariatric surgery is a crucial part of the journey toward overall well-being. To support all aspects of health, including bone health, it’s essential to follow a well-rounded approach.

According to the International Osteoporosis Foundation (IOF), maintaining an active lifestyle; prioritizing adequate intake of protein, calcium, vitamin D, and vitamin K, whether through dietary sources or supplements; and incorporating a variety of fruits and vegetables into your diet, can significantly lower the risk of developing osteoporosis. (7)*

Additionally, the ASMBS dietary guidelines are an essential resource tailored for patients, including appropriate vitamin and mineral supplementation. See Table 1 for recommendations on supplements post-operatively.* 

In addition to supplementation, always consider consuming nutrient-rich foods, including those high in calcium and vitamin D. Read food labels and self-monitor intake to ensure you meet the recommended levels. See Tables 2 and 3 for calcium and vitamin D amounts in foods.

Table 1: Recommended Baseline Vitamin and Mineral Supplementation after Metabolic and Bariatric Surgery (1)*

Surgery Type



Roux-en-Y Gastric Bypass Surgery (RYGB)

Sleeve Gastrectomy

Adjustable Gastric Band


Vitamin D

Vitamin K 

1,200-1,500 mg per day

3,000 IU (75 mcg) per day

90-120 mcg per day

Biliopancreatic Diversion with Duodenal Switch (BPD/DS)


Vitamin D

Vitamin K

1,800-2,400 mg per day

3,000 IU (75 mcg) per day

90-120 mcg per day

Table 2: Calcium in Foods


Calcium in mg

½ cup tofu


½ cup kombu seaweed


½ cup navy beans


½ cup kale


1 cup soy milk


1 cup collard greens


1 cup low-fat yogurt, plain


1 cup skim milk


1 oz. cheese


Table 3: Vitamin D in Foods


Vitamin D in IU

1 cup hemp milk


1 cup rice milk


1 cup soy milk


1 Tbsp. cod liver oil


3 oz. salmon


1 cup almond milk


3 oz. tuna, canned


1 cup skim milk



Although metabolic bone conditions are a legitimate concern after metabolic and bariatric surgery, they should not deter you from this transformative journey toward better health.

The key is to make informed decisions, be mindful of bariatric nutrition guidelines and lab tests, and follow up with healthcare professionals. Also, consider a bone scan to establish a baseline for your current bone health.

By proactively addressing bone health concerns, you can unlock the full potential of your post-surgery experience and enjoy a healthier, more fulfilling life. 


1. Parrott J et al. Surg Obes Relat Dis. 2017;13(5):727-741.
2. Ciobârcā D et al. Nutrients. 2020;12(1):235.
3. Shahraki MS et al. Adv Biomed Res. 2022;11:92.
4. Elijovich F et al. Hypertension. 2016;68(3):e7-e46.
5. Food and Drug Administration (FDA). 2023. Spilling the Beans: How Much Caffeine is Too Much? Accessed October 18, 2023.
6. Berman NK et al. Osteoporos Int. 2022;33(6):1235-1241.
7. Martiniakova M et al. Nutrients. 2022;14(3):523.

    *These statements have not been evaluated by the Food & Drug Administration (FDA). These products are not intended to diagnose, treat, cure, or prevent any disease.

    This blog is for information and education purposes only. This information is not intended to substitute professional medical advice, diagnosis, or treatment. Please consult with your bariatric surgeon or another qualified healthcare provider with any questions in regards to a medical condition. A qualified healthcare professional can best assist you in deciding whether a dietary supplement is suitable based on your individual needs.

    Dr. Lillian Craggs-Dino is a retained consultant for Bariatric Fusion.

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