Bone growth (and the deposition of new bone-building material) occurs from fetal life through childhood, puberty, and finishes as a young adult. During the teenage years, when our bone maturation accelerates (think growth spurts and those wonderful gangly teenage years that many of us experienced), it is particularly important to support bone health through healthy dietary and exercise habits. But when the maintenance phase is entered in adult life, all hope is not lost – there is a lot we can do to protect and even strengthen our bones.
Once we reach adulthood and our growth has stabilized, our bones often aren’t given much consideration until the later part of life (unless, of course, trauma is experienced). But how our bone health is maintained throughout mid-life often dictates how our bones will respond to the aging process. Specifically, the prevention of bone diseases such as osteoporosis through consuming a nutrient dense diet and having consistent exercise habits, becomes vitally important.
While many nutrients work in harmony to promote bone health, calcium and vitamin D are superstar nutrients when it comes to our bones. These two nutrients have a unique, interdependent relationship to support our bones; specifically, vitamin D is needed to promote calcium absorption and maintain normal blood levels of calcium. Vitamin D also works with other nutrients and hormones to promote bone mineralization (which is essential for their hardness and strength). For your reference, the Recommended Dietary Allowances (RDAs) for calcium and vitamin D are listed in the following table:
1. RDAs for Calcium and Vitamin D
mg=milligrams, IU=international units
|8–19 years||1300 mg||600 IU|
|19–50 years||1000 mg||600 IU|
|51–70 years||1200 mg||600 IU|
|>71 years||1200 mg||800 IU|
As the food that we eat can significantly affect our bones, learning about the foods that are rich in calcium, vitamin D and other nutrients (such as magnesium and vitamin K) that are important for bone health can help us decide when making food choices every day. To roughly assess the calcium in your diet consider using the following equation, where:
A = # Dairy product servings x 300 mg (one serving is defined as 1 cup of milk, 3/4 cup of yogurt, or ~50 g of cheese)
B = # Cups calcium-fortified milk alternatives or fortified foods x 300 mg
C = Rest of diet provides ~200-300 mg/day in most people
And A + B + C = your approximate daily calcium intake
With an understanding of your daily RDA, and armed with a method of estimating your daily calcium intake, check out chart 2 below for examples of the different foods rich in micronutrients important for bone health.
2. Bone Benefitting Foods
|Dairy products such as milk, yogurt and cheese||Calcium. Some dairy products are fortified with Vitamin D.|
|Canned sardines and salmon (with bones)||Calcium|
|Fatty varieties such as salmon, mackerel, tuna and sardines||Vitamin D|
|Fruits and Vegetables|
|Collard greens, turnip greens, kale, Chinese cabbage and broccoli||Calcium|
|Spinach, beet greens, tomato products, potatoes, sweet potatoes, collard greens and raisins||Magnesium|
|Tomato products, raisins, potatoes, spinach, sweet potatoes, oranges, orange juice, bananas and prunes||Potassium|
|Red peppers, green peppers, oranges, broccoli, strawberries, brussel sprouts and pineapples||Vitamin C|
|Dark green leafy vegetables such as kale, collard greens, spinach, mustard greens, turnip greens and brussel sprouts||Vitamin K|
|Certain brands of juices, breakfast foods, milk and milk alternatives, cereals, snacks and breads||Calcium, Vitamin D|
A Note on Protein and Energy Intake
As protein makes up 20-30% of bone mass, and evidence suggests that a higher protein intake leads to a higher intestinal calcium absorption, we want to make sure we’re eating enough protein. To ensure you’re fitting protein into your meals throughout the day, we recommend eating a source of lean protein with each meal.
If you’re trying to lose fat, it is very important that you curb your energy intake moderately through appropriate and sustainable methods; we strongly discourage undertaking periods of aggressive calorie restriction to induce weight loss without the supervision of a health professional. Loss of energy often equals loss of mass, including bone.
Some Dietary Culprits that do not Support Bone Health
Salty foods. Consuming sodium beyond what the body needs will cause your body to lose calcium and can lead to bone loss. Try to limit the amount of processed foods and salt added to the foods you eat each day. To learn if a food is high in sodium, look at the % Daily Value on a foods Nutrition Facts Table – if it lists 20% or more, it is considered to be high in sodium. Aim to consume no more than 2,300 mg of sodium (~1 tsp) per day.
Phytates and oxalates. These substances bind up minerals and prevent our bodies from extracting them. Phytates are found in significant amounts in grains, seeds and nuts. Oxolates are found in spinach, rhubarb, sweet potatoes and walnuts. Therefore, because of poor mineral absorption, these foods are not good sources of calcium. Foods containing these substances, which are beneficial for a host of other reasons, should not be consumed with a view to increase your calcium intake.
Alcohol. While being detrimental to your overall health, drinking heavily can lead to bone loss. Limit alcohol to no more than 2-3 drinks per day.
Caffeine. Excessive caffeine consumption has been shown to decrease calcium absorption and contribute to bone loss. Consume food and beverages high in caffeine (such as coffee, tea and chocolate) in moderation. Aim to limit your intake of caffeine to 400 mg per day – that’s about three 8 oz cups of brewed coffee or nine cups of black tea.
Soft drinks. Some studies suggest that colas are associated with bone loss. However, more research will help us to better understand the link between soft drinks and bone health.
Research on the topic of dietary habits and bone health has produced a number of other interesting findings. Here are some thought-provoking highlight of what we’ve found:
Recent Research on Bone Health
Recent research has found that many foods (including olive oil, soy beans, blueberries and foods rich in omega-3) may have bone boosting benefits. Studies have also demonstrated that a moderate intake of certain beverages (including wine, beer and tea) may also be good for our bones. More research is needed on these research findings to help us to better understand the relationship between these food and drinks and bone health.