Nutrition is a key component to bone health because certain nutrients form the structure of bone and play a role in bone development. There are several nutrients that are essential for bone health: calcium, vitamin D, protein, as well as lesser recognised nutrients like magnesium, phosphorus and potassium.
If you eat a varied diet from the five food groups, meeting nutrient needs for bone health is generally not a problem. However in recent times, the health benefits of dairy – the main food source of calcium - has come under question, plus the rising popularity of vegan diets has lead to many people, including children, to cut dairy from their diet. If calcium isn’t replaced with other dietary sources or a supplement, there is greater risk of brittle bones later in life.
Overall, research has shown that dairy, especially fermented dairy like yoghurt and cheese has a neutral, or positive effect on health, and is an easy and convenient way to get the nutrients needed for bone formation.
Low bone mineral density is known as osteopenia and as bone density decreases further, it is known as osteoporosis. Osteoporosis causes bone to become weak, thin and fragile and increases the risk of fractures. Osteoporosis can cause chronic pain, loss of mobility and independence. Nearly one in four people with osteoporosis with a hip fracture dies within a year.
The main nutritional recommendations for bone health include:
Calcium
Calcium is one of the main ingredients in bone and because we don’t make it in our body, we can only get it from our diet. If we don’t have enough calcium in our blood, the body will strip it from our bones, weakening them over time.
General calcium requirements are 1000mg per day, but in late teens and after menopause, requirements go up to 1,300mg per day – that is the equivalent of four serves of dairy foods per day.
A serve of dairy is 1 cup of milk, 200mL yoghurt, 2 slices of hard cheese or ½ cup of fresh cheese like cottage cheese. Lesser sources of calcium include green leafy vegetables like spinach, almonds, the bones in canned salmon.
Vitamin D
Vitamin D helps our body to absorb calcium in the gut, and regulate blood levels which are needed to build bone. The main source of vitamin D is from safe sun exposure. However some foods do contain small amounts of vitamin D, such as milk, eggs, mushrooms and oily fish like salmon.
Protein
Protein forms a framework for bone growth. The best dietary sources are dairy products, fish and seafood, meat, chicken, eggs, pulses, nuts and seeds.
Average adult protein requirement is calculated by multiplying our weight in kilograms by 0.8g. For example, if you weigh 70kg, general protein requirements would be 56g per day.
Some people, especially post-menopausal women may be unable to meet increased dietary requirements of these nutrients and may need to take a supplement. Other lifestyle factors that are important for bone health include regular physical activity, avoiding smoking and excessive alcohol intake, as well as some medications. For specific advice, make sure to speak to your doctor or dietitian.
Links to references:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3330619/
https://www.health.harvard.edu/staying-healthy/essential-nutrients-your-body-needs-for-building-bone
https://www.health.harvard.edu/blog/dairy-health-food-or-health-risk-2019012515849
https://healthybonesaustralia.org.au/osteoporosis-you/diagnosis/
https://www.aihw.gov.au/reports/chronic-musculoskeletal-conditions/osteoporosis/contents/what-is-osteoporosis