Overview

Bones provide structural support to your body. They are very strong, yet they are not invincible. Under intense stress and/or powerful force, they can break. Bone fracture healing starts immediately after the fracture and can take up to years to complete. The healing timeline depends on various factors, such as age and the type of fractured bone, but overall, it is a continuous process that involves the following stages:

1. Inflammation 
2. Repair
3. Remodelling¹

The body has a natural ability to heal fractures; however, there are steps you can take to support and speed up the healing process. 

Following a balanced diet plays an important role in fracture healing. Nutrition is associated with bone health, and therefore, consuming a diet rich in nutrients, minerals, and vitamins can help your bones recover faster.² The key nutrients your body needs while recovering from a bone fracture are calcium, vitamin D, and protein.²

In this article, the importance of proper nutrition and an overall healthy lifestyle in the context of healing a bone fracture will be discussed. 

The 3 stages of bone healing 

Stage 1: Inflammation 

Your bones consist of multiple structural layers and contain blood vessels. When you fracture a bone, the blood vessels rupture, creating a hematoma (a blood clot).³ At the same time, your body’s first defensive mechanism is initiated, inflammation. White blood cells (the fighter cells) rush to the area of inflammation to clear out the damaged tissues. They also emit signals to attract more repair cells for extra help in recovering the damaged area.⁴

Stage 2: Repair

Within two weeks of a fracture, the hematoma coagulates and is gradually replaced by a soft callus, aided by cells such as fibroblasts, chondroblasts, and osteoblasts.⁵

• Fibroblasts are cells that make collagen to help the tissues attach and form a network. Ultimately, they bridge the ends of fractured bones
• Chondroblasts are cells that replace the soft callus with cartilage
• Osteoblasts (bone-building cells) release osteoid (bone matrix) to help compose the bone again

Up until four weeks after a fracture, osteoblasts manage to replace the soft callus with new, sturdy bone tissue (bone callus). This new structure, called woven bone, provides structural ability, but it serves as a temporary bone until a mature, more complete bone structure forms later.⁵

Stage 3: Remodelling 

Remodelling, the final stage of bone healing, can last months to years. This is where your cells work hard to bring the bone back to its original shape and function. The bone callus undergoes a remodelling process where osteoclasts absorb the temporary bone and osteoblasts replace it with a sturdy bone on the inside and a lamellar bone on the outside, peripherally.⁵

During those stages in bone healing, nutrition plays a vital role. To support your body in rebuilding a new bone, it is strongly recommended that you increase your intake of calcium, vitamin D, and protein.

The role of calcium in bone strength and healing

It's no coincidence that the saying 'we are what we eat' exists. If we could slice a bone and examine its internal structure, we would find that the bone matter is rich in calcium. Calcium is the main mineral in the bones, and its role is to harden and strengthen them. Your body does not produce calcium naturally; it receives it from your diet.⁶ When calcium intake is insufficient, the body gets calcium from the bones and distributes it wherever needed to supply other biological activities (for example, heart activity).⁷ Therefore, during bone healing, it is important to increase calcium intake to provide the necessary support to your bones.

The best dietary sources for calcium are dairy products, vegetables (e.g. broccoli), leafy greens (e.g. spinach), legumes, nuts (almonds), fortified foods (e.g. soy products, oatmeal) and seafood.² Based on your age and biological sex, you require different amounts of calcium per day. If you do not meet your optimal daily calcium intake from diet alone, you may need additional support from calcium supplements. It is important to consult a healthcare provider before taking a calcium supplement, as there are many different forms of calcium. They can recommend the one that best suits your needs and discuss potential adverse effects (e.g., gastrointestinal complaints).⁸

The average person absorbs 30% of the calcium they consume.² To help the body absorb calcium, it is important to pair calcium with vitamin D. 

The role of vitamin D in bone strength and healing

Vitamin D naturally exists in food and from sun exposure. Foods containing vitamin D include eggs, liver, and fish (salmon, tuna). Other food sources of vitamin D include orange juice, breakfast cereals and milk, though these are usually fortified.² Overall, vitamin D plays a crucial role in calcium absorption in the gut by:

1. Maintaining calcium levels in the blood 
2. Supporting bone growth and remodelling by giving “fuel” to osteoblasts and osteoclasts 

When vitamin D levels are low, bones can become fragile and brittle. Vitamin D insufficiency can lead to rickets in children and osteomalacia in adults.⁹ To ensure bone health and optimal holistic health at every stage of life, including during the healing of a fractured bone, it is important to follow a diet rich in vitamin D. A diet rich in both calcium and vitamin D with can help you achieve optimal bone mass, keep the bones strong and also reduce the risk of osteoporosis and bone loss later in life.²

The role of protein in bone strength and healing

Dietary protein is another important element in your diet that supports not only your overall health but also bone health. Bones are rigid and slightly flexible. Collagen, a protein that serves as the building block of bones, provides that flexibility. When healing from a fractured bone, collagen composes the soft callus and supports the activity of osteoblasts and osteoclasts. In particular:

1. Osteoblasts use dietary protein to create more collagen and further support bone building
2. Osteoclasts also use protein to help the bone regain its initial structural form⁵

Dietary protein is broken down in the body to produce various proteins. Collagen makes up about 30% of the body's total protein content.^2,10 The best sources of animal-derived protein are lean meat, fish, eggs, and dairy products. Alternatively, plant-based options include tofu, tempeh, quinoa, legumes, seeds and nuts. 

During a bone fracture, your body needs more protein, and therefore collagen, than usual to repair the damage and promote healing. The daily protein intake recommendation is 0.8 grams of protein per kilogram of body weight per day.¹¹  It is important to consult a healthcare provider for personalised guidance on your protein uptake during the healing of a bone fracture, as optimal levels depend on your age and personal needs. 

The role of other nutrients in bone strength and healing

Getting enough calcium, vitamin D and protein is undoubtedly crucial during bone fracture healing. However, there are other important nutrients that also play a role in the bone-strengthening process. These include:

• Vitamin C: found in fruits and vegetables (citrus fruit, kiwi, broccoli, and peppers). 
  It is linked to collagen synthesis and increased bone density, accelerating fracture healing²
• Magnesium: found in spinach, legumes, nuts, and whole grains.
  Up to 60% of magnesium is found in the bones. Increased intake enhances bone quality and health and may increase bone mineral density¹²
• Zinc: found in oysters, meat, beans, nuts, and seeds. Bones store most of the zinc in the body. It plays an important role in skeletal development and bone growth, and it helps achieve optimal bone density^2,13
• Micronutrients: Vitamin A and Vitamin K are found in leafy green vegetables such as spinach, broccoli, and cabbage. Vitamin B12 is found in fish, meat, eggs, dairy products, and nutritional yeast. Vitamins A, K, and B12 are all important in bone development, density, and maintenance²

Lifestyle factors that influence bone recovery

Staying active 

When recovering from a fractured bone, the right adjustments in nutrition can play a key role, but it is equally important to incorporate light movement to enhance recovery effectiveness. A healthcare provider may advise physiotherapy to introduce safe, gentle movement to help regain strength and mobility. By restoring strength, you also reduce the risk of falls and further bone fractures.¹⁴

Avoid smoking and consuming alcohol 

Alcohol consumption and smoking have a negative impact on bone healing. Smoking can affect the skeletal system by reducing bone mass, while alcohol consumption is encouraged to be kept below 2 servings per day.^15,2

Summary

Humans are not invincible - at some point in life, you may fracture a bone. Healing takes time, but as your body attempts to reconstruct the bone, there are steps you can take to support the process. Following a balanced diet is crucial during the healing of a bone fracture. Healthy, strong bones require sufficient amounts of calcium, vitamin D, and protein. Additionally, other micronutrients, including magnesium, zinc, and vitamins (A, C, K, and B12), play an equally important role in bone healing and remodelling. Dietary nutrients work together to enhance each other’s function and provide your body with sturdy bones. It is also important to keep a healthy lifestyle when healing a fracture by limiting alcohol and smoking. 

When you heal from a bone fracture, consult a healthcare provider for personalised advice, as you may need to increase the intake of calcium, vitamin D and protein to cope with your body’s increased need for nutritional support.