
The Role of Diet in Bone and Muscle Health
Published: 9 January, 2025 | 13'
Our skeleton, along with the muscles, is responsible for maintaining the body's structure and allows us to perform any movement. However, they also play a key role in the care of the most important organs. Like all systems in our body, the musculoskeletal system requires certain key nutrients that can support its proper functioning.
We explain the role of diet in our bones and muscles and how we can adapt it to the different stages of our life with the help of Doctor José Luis Castilla, a specialist in physical medicine and rehabilitation.
Relationship Between Nutrition and the Skeletal and Muscular System
A balanced diet, regular physical activity, and the maintenance of healthy habits are the three allies that will form the basis for having healthy bones and joints.
“Calcium, vitamin D, collagen, and many other nutrients are key to musculoskeletal care, particularly relevant during growth, periods of physical demands, or during older ages,” explains the doctor. Let’s look at the function of each of these nutrients and how we can include them in our diet.
Why is Bone Health Essential?
The main function of the skeletal system is to keep the body upright and enable movement for mobility. It also acts as a shield by housing vital organs such as the brain, heart, and lungs. It serves as storage for minerals that have positive effects on bone rigidity and density and that are used by the muscles and nerves.
Lastly, within the bones is bone marrow, which can be classified into red and yellow marrow. Bone marrow plays a crucial role in the production of blood components and essential cells for the proper functioning of the immune system. It is in the yellow bone marrow where some fats are stored that will be used as an energy reserve for the body.
Key Nutrients for Our Bones and Joints
A diet is adequate when it provides a sufficient supply of nutrients that meets the body's needs. In this case, our bones are primarily made of minerals such as calcium and phosphorus, but also of proteins and other substances involved in bone metabolism, which we obtain directly from our diet. The same is true for muscles, as, in addition to proteins, some minerals and vitamins also play a role in their functioning.
Calcium
The main driver of the proper functioning of our bones and joints is calcium, along with proteins. Calcium is stored in up to 90% of total body calcium in the bones, but it is involved in numerous vital functions throughout the body. Its primary role is as a fundamental structural component of bones, aiding in their formation and density, but it is also involved in processes such as nerve transmission and muscle contraction. Our body does not produce it, so we must ingest it through our diet.
Vitamin D and Vitamin K
The function of vitamin D is linked to the supply of calcium, as it contributes to the normal absorption and utilisation of this mineral. Additionally, it is a key nutrient that contributes to the maintenance of bones under normal conditions, and also helps maintain normal levels of calcium in the blood.
Vitamin D is naturally present in our body but in an inactive form. It is the ultraviolet light emitted by the sun's rays that activates this nutrient into its D3 form (cholecalciferol) so it can be utilised.
Furthermore, vitamin K is also essential as it contributes to the maintenance of bones under normal conditions and aids in the integration of calcium into the bones, which is why it is common to find both forms in dietary supplements.
Magnesium
Magnesium is mostly deposited in the bones, but it also plays a key role in muscle tissues and other organs such as the brain, heart, or liver. Furthermore, it contributes to normal protein synthesis and the maintenance of bones under normal conditions.
Phosphorus
Another micronutrient found in bones is phosphorus, which is the second most abundant mineral in the body. It plays roles in the formation of bones and teeth as well as in various processes such as protein production or fat metabolism.
The Role of Collagen and Vitamin C
Collagen is the most abundant protein in our body, found in the skin, cartilage, and connective tissues, being an essential part of the structures in the body, such as joints. As we age, our body's collagen reserves decrease. Therefore, it is crucial to include it in the diet.
On the other hand, one of the properties of vitamin C is to contribute to the normal formation of collagen for the normal functioning of bones, cartilage, skin, among others. Thus, its function is complementary.
Chondroitin and Glucosamine
About 90% of the organic matrix of bones is made up of collagen, with the remaining 10% consisting of proteoglycans such as glucosamine and chondroitin. Both substances play a key role in the formation of cartilage by providing elasticity.
Key Nutrients for Muscle Health
Like our bones and joints, muscles are essential for our movements and require certain nutrients that support their structure and functioning, primarily proteins and carbohydrates.
Proteins
Proteins are present in all the cells of our body and are vital for creating new ones. Proteins participate in the proper functioning of our body, engaging at the muscular level in the maintenance and renewal processes of muscle tissues.
Proteins are formed by hundreds or thousands of units called amino acids. Our body cannot produce certain amino acids, known as essential, so we must obtain them from our diet.
Carbohydrates and Healthy Fats
In any metabolic process, our body requires energy, which it obtains from various sources, although carbohydrates are the main one, as they make up a large part of the calories we consume. Additionally, carbohydrates are stored as glycogen and represent the metabolic fuel of choice in muscle metabolism during intense exercise. Complex carbohydrates (found in whole grain products, legumes, and vegetables) are absorbed more slowly than simple carbohydrates (in refined flours and industrial baked goods), constituting the energy reserves.
On the other hand, fats are also one of the main fuels providing energy during exercise, serving as an energy reserve that muscles can utilise during activity.
Minerals (Magnesium and Potassium)
As mentioned earlier, magnesium is also present in muscle tissues and contributes to the normal functioning of muscles, participating in the relaxation process after physical activity. Potassium, for its part, also contributes to the normal functioning of muscles since it is involved in the muscle contraction process, in addition to performing functions related to the care of the nervous system.
Hyaluronic Acid
Hyaluronic acid is a polysaccharide with positive effects on the hydration and elasticity of tissues. In joints, hyaluronic acid plays a key role in the nutrition and lubrication of these. When the joints are lubricated, there is less likelihood of rubbing between the joint surfaces during movement, thus reducing the chances of discomfort.
Healthy Diet: Caring for Bones and Muscles
As we have seen, there are many nutrients involved in the well-being of our musculoskeletal system, which can be found in various foods and in dietary supplements.
Foods that Support Bone and Muscle Health
- Dairy products are high in calcium, such as milk, cheese, and yogurt, but also some nuts like almonds and hazelnuts, sardines, and legumes such as chickpeas or beans.
- Due to their magnesium and other nutrient content, leafy greens such as spinach and broccoli are also beneficial.
- Nuts and seeds are rich in calcium as already mentioned, but also in proteins and unsaturated fats.
- Whole grain products like oats, pasta, bread, and other whole cereals are high in complex carbohydrates.
- Fatty fish or oily fish such as salmon, tuna, and anchovies are high in unsaturated fats, vitamin D, and minerals like calcium and phosphorus.
- Chicken, turkey, or tofu are sources of lean proteins involved in muscle development.
Eating Habits that Affect Bone and Muscle Health
Sodium is involved in fluid balance in the body and in the functioning of the nervous system and muscles, although in excess, sodium levels in the blood can rise, leading to elevated blood pressure. “It is important to control your intake and avoid consuming ultra-processed foods, fast food, and cold cuts, and pay attention to product labelling,” recommends the doctor.
A high consumption of sugars and refined flours, such as those found in industrial sweets, ready meals, and processed foods, causes very rapid spikes in blood glucose levels but offers little to no nutritional value, meaning they do not provide positive effects on the body in the long term.
Moreover, an excessive intake of caffeine or tea is associated with a limitation in the absorption of certain minerals, such as iron. This is due to the presence of compounds called polyphenols which bind to these minerals and impede their absorption. Therefore, it is ideal not to consume more than 2 or 3 cups a day. Similarly, alcohol is related to the malabsorption of some nutrients and has negative effects on bone formation.
Finally, a low-calorie diet will also have negative effects on muscle development since carbohydrates and fats are the foundation of the energy used for their proper functioning.
Impact of Exercise and Diet on Bone and Muscle Well-being
“Physical exercise and nutrition are the main allies that promote the good condition of bones and joints,” explains Dr. Castilla, “among all the nutrients involved in the health of our bones and muscles, calcium, vitamin D and proteins are the most important.” Therefore, a balanced diet with a high content of the aforementioned nutrients, combined with regular exercise throughout our lives, promotes the development of bone mass and density, as well as muscle function.
After puberty and into adulthood, around the age of 25, we reach the peak of our bone density. As we age, bone density decreases, generally from the age of 40. When there is a decrease in bone density, the levels of minerals that form part of the bone decrease, making the bones more fragile and increasing the risk of bone-related conditions. Therefore, “it will be vital to care for diet and lifestyle in order to maintain adequate levels of these minerals and to delay age-associated loss for as long as possible,” he continues. In exercise practice, a combination of strength and aerobic activities will be ideal in these situations, including:
- Exercises with quick movements, avoiding slow and static ones.
- Strength exercises that oppose resistance and weight.
- Impact movements such as walking or running.
- Exercises that involve multiple muscle groups.
“In cases of older ages or when some condition or discomfort arises, the type of sport should be adapted with the help of a rehabilitation specialist, and high-impact activities should be limited,” recommends the doctor, “but always maintaining exercise practice to support the involved musculature and reduce the risk of future complications.”
Conditions Related to Diet and Bone and Muscle Well-being
There are several factors that can alter the composition of the osteoarticular system, relating to muscular or joint conditions that limit movement. “The natural aging of the body, rheumatic conditions or those associated with wear and tear of structures, lifestyle factors such as intense physical exercise, certain jobs, and even environmental changes such as low temperatures or humidity can affect the state of our bones and joints,” explains the doctor.
Among these factors, diet is also particularly significant, as proper nutrition is fundamental to our overall well-being, including the processes involved in bone and muscle care, ensuring the body receives the necessary nutrients.
Osteopenia and Osteoporosis: Relationship Between Nutrient Levels and Bone Density
Osteopenia occurs when bones lose more bone density than usual, typically increasing in severity over time and leading to osteoporosis, which occurs when bone density decreases below marked levels and bones become even more fragile, increasing the risk of fracture.
Women generally have a higher predisposition to its onset due to the decrease in estrogen levels during menopause, but it is also significantly affected by inadequate intake of calcium or vitamin D.
The best measure against these age-related conditions is: an adequate intake of calcium and regular physical exercise during adolescence and youth, which promotes an increase in bone density. The consumption of calcium and vitamins in maturity is key for bone care.
Sarcopenia: Muscle Mass with Age
The decrease in muscle mass and muscle function is known as sarcopenia, and occurs as part of the natural aging process progressively. It leads to a weakening and loss of physical strength and endurance, as well as balance, which increases the risk of falls.
In this context, engaging in strength exercises, avoiding sedentary behaviour, and paying attention to diet will be the best way to delay the onset of this situation in older ages. Nutrition should be varied, ensuring a high intake of proteins, carbohydrates, and minerals such as magnesium.
Muscle and Bone Injuries: Diet Low in Nutrients
Inadequate levels of certain minerals such as calcium and magnesium, or certain vitamins such as D, can be associated with an increased risk of potential discomfort. Furthermore, with age and due to the natural aging process, our bones and muscles progressively weaken, and our joints undergo changes in cartilage and connective tissue. Together, this increases the risk of any type of injury.
Other Metabolic Conditions: Hypocalcemia, Vitamin D Deficiency and Their Relationship with Diet
There are other factors that can lead to the malabsorption of some nutrients. For example, “a disruption in the parathyroid glands can alter the amount of calcium present in the blood and that excreted through urine, leading to low calcium levels in the blood due to increased excretion,” informs Castilla. This condition is known as hypocalcemia. A balanced and varied diet, as well as a healthy lifestyle, can promote adequate calcium levels, which can be complemented with calcium and vitamin D supplements.
On the other hand, “low levels of vitamin D or vitamin D deficiency can also occur, due to diet, lack of sun exposure, or due to a condition that interferes with the activation of this nutrient in the body,” continues. This can lead to reduced bone density and a greater risk of bone conditions.
Dietary Recommendations by Age
Our bones are subject to a continuous process known as remodelling. In this process, existing bone tissue is gradually replaced by new bone tissue. Bone remodelling occurs throughout life, however, around the age of 30, when peak bone density is reached, the balance stops being positive, although it remains relatively stable until the age of 50. From this age, during the remodelling process, bone resorption predominates, leading to a decrease in bone density.
The process is similar with muscle mass; from 25-30 years old, peak muscle mass is reached and it is from 50 years onwards that a gradual decrease in muscle becomes noticeable, which increases with age as the number of muscle fibres declines.
We will focus on the recommended and indicative nutritional values of the key ingredients in these two areas, calcium, vitamin D, and proteins, since there are other factors to consider such as weight, gender, and whether women are pregnant or breastfeeding.
In any case, a healthy, balanced diet, a healthy lifestyle, and following the advice of a healthcare professional assessing our prior condition will enable us to achieve the recommended intake values. Furthermore, the diet can be complemented with dietary supplements.
Nutrition in Childhood and Adolescence: Bone and Muscle Well-being
“Adequate intake of nutrients such as calcium and vitamin D is important for good bone density during childhood and adolescence and therefore provides an adequate “reserve” of bone tissue,” informs the doctor, “reducing the likelihood of age-related conditions such as osteoporosis.” Additionally, during childhood, new foods and protein intake start to be introduced.
AGE | CALCIUM (mg/day) | VITAMIN D (IU/day) |
4 - 8 years | 800 mg | 600 IU |
9 - 18 years | 1,150 mg | 600 IU |
Bone and Muscle Well-being in Adults
During childhood and adolescence, attention is usually paid to the intake of nutrients necessary for growth that have positive effects on bones and muscles; however, it is also crucial to continue caring for the diet in adulthood and older ages, which will promote the proper functioning of the body and thus reduce potential discomfort. In adulthood, therefore, “one should monitor bone density and muscle mass through diet alongside an active lifestyle and exercise practice,” explains the doctor.
AGE | CALCIUM (mg/day) | VITAMIN D (IU/day) |
18 - 50 years | 950 mg | 600 IU |
Monitoring Bone Density and Muscle Mass in Older Age
“In older ages, we must focus on controlling osteoporosis and sarcopenia resulting from the natural changes brought about by age,” concludes Castilla. This can be achieved with a balanced diet that includes high-quality proteins and a combination of regular low-impact exercise.
AGE | CALCIUM (mg/day) | VITAMIN D (IU/day) |
51 - 70 years | 950 mg | 600 IU |
Greater than 71 years | 950 mg | 600 IU |
If you want to know more about bone and joint health...
- Knee Injuries: Symptoms, Causes, Risk Factors, and How to Prevent Them
- Sports Injuries: Why They Occur and What Are the Most Common?
- Minerals, Importance in Our Body
Content prepared in collaboration with Dr. José Luis Castilla. This article is informative and does not replace a consultation with a specialist.
About the Specialist
He has more than 20 years of experience in medicine, particularly in rehabilitation and traumatology. He currently works as a specialist in Physical Medicine and Rehabilitation in the Andalusian Health Service, and also serves as the Medical Director at Centro Médico Dharma.