Bone Health Explained: How Bones Stay Strong

A guide to bone health: 

• Bone health is influenced by factors such as nutrition, physical activity, hormones, sleep and lifestyle habits throughout life.
• Bones are constantly being broken down and rebuilt through a process called bone remodelling, which helps maintain bone strength and quality.
• Nutrients, including calcium, vitamin D, magnesium, vitamin K and protein, contribute to normal bone health as part of a balanced diet.
• Regular weight-bearing exercise, resistance training, safe sunlight exposure and not smoking can help support healthy bones over time.

It's easy to think of bones as fixed scaffolding, set in place and unchanging. In reality, they’re actually living tissue, quietly renewing themselves. Because of this, your everyday choices can play an important role in supporting healthy bones1.

This practical guide explores what healthy bones are, how they change as you age and the biology that helps keep them strong.  

What is bone health?

Bone health refers to the strength, structure and quality of your bones, and how well they support everyday movement and protect your body. 

Bone is a living tissue that’s strong enough to withstand intense activity, adaptable enough to respond when your activity levels change, and light enough to let you move efficiently. Its resilience comes from both its material make-up (things like mass, density and mineral composition) and its dimensions (size, shape and structure)2.

What makes bone special is that it’s constantly changing. Bone tissue is continuously maintained and renewed through a process called remodelling. This helps it adapt to the loads placed on it over time3. Because bone adapts to the demands placed on it, movement plays a vital role in maintaining healthy bones. Regular exercise can help protect bone mass and strength as you age4.

Why does all this matter? Healthy bones can help support mobility, independence and everyday movement throughout life. Understanding how bones work can also help explain why factors such as physical activity, nutrition and lifestyle habits play an important role in maintaining bone health.  

How bones change throughout life

Your bones are constantly changing, and their needs evolve throughout different stages of life. 

Childhood and adolescence are the big building years. Bone mineral content rises rapidly during this time. In fact, 40 to 60% of your total adult bone mass is accumulated during puberty5. By the end of your first two decades, you've reached what's called peak bone mass: essentially, the maximum strength your skeleton will reach. While genetics account for an estimated 60 to 80% of it, diet, physical activity and hormones can also contribute to bone health6.

Young adulthood is more of a maintenance phase. Between roughly the ages of 20 and 50, bone mass remains relatively steady. However, bone tissue does continue to be renewed through the ongoing process of remodelling5.

Midlife and beyond is when bone mass naturally begins to decline, generally after age 505. For women, menopause can accelerate this process. As oestrogen levels decrease, bone breakdown can occur more quickly while new bone formation slows, contributing to a decline in bone density7 8.  

How bones stay strong 

Your bones are in a constant state of renewal, and this process relies on two specialised  cell types that work together to maintain healthy bones9.

• Osteoblasts are the builders, forming new bone tissue. 
• Osteoclasts are the recyclers, breaking down and removing old bone tissue. 

These cells coordinate their activity to ensure that older or damaged bone is replaced with new bone10. When osteoclasts break down bone tissue, osteoblasts step in to rebuild it11.  

When this process is balanced, bone strength and quality can be maintained over time. However, factors like ageing, hormonal changes can shift that balance, causing bone breakdown to occur more quickly than new bone is formed. Over time, this can contribute to a gradual decline in bone strength.   

What is good for bone health? 

When it comes to bone health, there isn’t a single nutrient, food or habit that does all the heavy lifting. Instead, healthy bones are supported by a combination of factors, including:

• A balanced diet: Nutrients such as calcium and vitamin D help support normal bone health12. Dairy products like milk, yoghurt and cheese, fish, nuts and seeds can be a great source of calcium. 
• Regular physical activity: Bones respond to the demands placed on them, making movement an important part of maintaining bone strength. 
• Sunlight exposure: Most of the body’s vitamin D is produced in the skin in response to daylight12. Safe outdoor activity can support vitamin D production while following recommended sun protection measures and support health bones as well.  
• Good-quality sleep: Bone remodelling follows a daily rhythm, and emerging research suggests sleep may play a role in bone health over time13. 
• Healthy lifestyle habits: Factors such as not smoking and maintaining your overall wellbeing can also support long-term bone health6. 

So, if you're wondering how to keep your bones healthy, the answer is usually found in consistent habits rather than any single solution. A balanced diet, regular movement, adequate sleep and safesunlight exposure can all contribute to supporting bone health throughout life. 

Nutrients linked to bone health

There are a few nutrients that play a role in supporting bone health. These include: 

• Calcium. 99% of the calcium in your body is stored in your bones and teeth, and beyond building bone, it also helps your blood to clot, your muscles contract and your heart beat14. However, many people fall short of recommended intakes2. Food sources include dairy, tinned fish with bones, leafy greens, nuts and seeds.
• Vitamin D helps your body to absorb calcium and supports the muscles that helps you stay steady and avoid falls15. Because it's hard to get enough from food alone, safe sunlight exposure is the main source for most people.
• Magnesium contributes to healthy bone metabolism by supporting the balance between osteroblasts (bone-building cells) and osetoclasts (bone-resorbing cells). Inadequate magnesium intake has been linked to poorer bone health outcomes16 17. 
• Vitamin K contributes to the function of osteocalcin, a protein made by osteoblasts that's important for bone building. Inadequate vitamin K intake may be associated with less favourable bone health outcomes18 19 . Leafy green vegetables are a key source.
• Protein  provides the foundation that helps keep bones strong. Because it forms much of bone’s structure, getting enough protein alongside calcium can help support healthy bones20 21.

Risk factors for poor bone health

Bone health is influenced by a combination of genetic, hormonal, lifestyle and environmental factors. Some of these factors are beyond your control, while others can be influenced by everyday habits. 

Factors that have been associated with poorer bone health include22:

• Family history and genetics
• Hormonal changes such as menopause
• A history of fractures
• Long-term use of certain medications like corticosteroids
• Lower nutrient intake or absorption (particularly calcium and vitamin D)22. 

However, there are certain lifestyle factors that have also been linked to poorer bone health, including:

• Low body weight or low BMI
• Physical inactivity
• Uncontrolled weight loss
• High alcohol intake and smoking 

When several of these stack up together, the impact on bone tends to be greater than any one factor on its own23.

How to improve bone health

Supporting bone health is often about consistent habits maintained over time. The good news is that the same habits that support overall health and wellbeing can also help support healthy bones throughout life. 

• Move in ways that load your bones. Physical activity helps maintain bone mass and can reduce the risk of falls. All forms of physical activity can support bone health, with weight-bearing activities such as walking, jogging and dancing, along with resistance training, being particularly beneficial.¹⁵ 
• Try resistance training. In older adults,extended periods of resistance training programs using moderate-to-heavy loads have been shown to improve bone density at sites such as the spine and hip.¹⁵ 
• Eat for variety. Focus on including calcium-rich foods and a variety of other important nutrients as part of a healthy, balanced diet. 
• Support vitamin D. Safe sunlight exposure can help the body produce vitamin D, while some people may choose to discuss supplementation with a healthcare professional. 
• Limit smoking and excess alcohol intake. Both have been associated with poorer bone health outcomes. 

If you have concerns about your bone health, risk factors for bone loss, or a family history of bone-related conditions, speak with your healthcare professional. They can provide personalised advice and determine whether further assessment is appropriate. 

Supporting bone health over time

Bone is a living tissue that is continuously being renewed throughout life. Bone health is shaped by many factors, including physical activity, nutrition, hormones, lifestyle habits and the natural ageing process.

While some influences on bone health cannot be changed, many everyday habits can help support healthy bones over time. Regular movement, a balanced diet, adequate vitamin D and other lifestyle habits can all contribute to maintaining bone health throughout life.

Looking to learn more? Explore the Swisse Wellness Hub for more articles on joint health and our guide to calcium. 

References: 

1. Sheng, B., Li, X., Nussler, A. K., & Zhu, S. (2021). The relationship between healthy lifestyles and bone health: A narrative review. Medicine (Baltimore), 100(8), e24684. https://doi.org/10.1097/MD.0000000000024684 
2. Office of the Surgeon General (US). (2004). Bone Health and Osteoporosis: A Report of the Surgeon General (Chapter 6: Determinants of Bone Health). https://www.ncbi.nlm.nih.gov/books/NBK45503/ 
3. Docaj, A., & Carriero, A. (2024). Bone health: Quality versus quantity. Journal of the Pediatric Orthopaedic Society of North America, 100054. https://doi.org/10.1016/j.jposna.2024.100054. https://pmc.ncbi.nlm.nih.gov/articles/PMC12088120/ 
4. Santos, L., Elliott-Sale, K. J., & Sale, C. (2017). Exercise and bone health across the lifespan. Biogerontology, 18(6), 931–946. https://doi.org/10.1007/s10522-017-9732-6 
5. Weaver, C. M., et al. (2016). Understanding the importance of peak bone mass. https://pmc.ncbi.nlm.nih.gov/articles/PMC12088333/ 
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7. Hormonal Changes During Menopause and Their Impact on Bone Health: Insights from Orthopedic and Reproductive Medicine. (2025). Elsevier. https://pmc.ncbi.nlm.nih.gov/articles/PMC12464279/ 
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9. Kular, J., Tickner, J., Chim, S. M., & Xu, J. (2012). An overview of the regulation of bone remodelling at the cellular level. Clinical Biochemistry, 45(12), 863–873. https://pubmed.ncbi.nlm.nih.gov/19319579/ 
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11. Rachner, T. D., et al. (2014). Pathophysiology of bone remodelling and current therapeutic approaches. Geburtshilfe und Frauenheilkunde. https://pmc.ncbi.nlm.nih.gov/articles/PMC4168398/ 
12. Muñoz-Garach, A., García-Fontana, B., & Muñoz-Torres, M. (2020). Nutrients and dietary patterns related to osteoporosis. Nutrients, 12(7), 1986. https://doi.org/10.3390/nu12071986 
13. Swanson, C. M., Kohrt, W. M., Buxton, O. M., Everson, C. A., Wright, K. P. Jr, Orwoll, E. S., & Shea, S. A. (2018). The importance of the circadian system & sleep for bone health. Metabolism, 84, 28–43. https://doi.org/10.1016/j.metabol.2017.12.002 
14. National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS). (2023). Calcium and vitamin D: Important for bone health. U.S. Department of Health and Human Services. https://www.niams.nih.gov/health-topics/calcium-and-vitamin-d-important-bone-health 
15. Bone Health & Osteoporosis Foundation. (2023). Calcium/vitamin D requirements, recommended foods & supplements. https://www.bonehealthandosteoporosis.org/patients/treatment/calciumvitamin-d/ 
16. Razzaque, M. S., et al. (2024). Magnesium matters: A comprehensive review of its vital role in health and diseases. https://pmc.ncbi.nlm.nih.gov/articles/PMC11557730/ 
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