Which are the best foods for kids’ bone health? (it’s not just about calcium)
When it comes to building strong bones in children, most of us follow the advice we grew up with - drink your milk, eat your dairy, make sure you're getting enough calcium. And while calcium is absolutely important, it is only one piece of a much bigger picture.
The truth is that bone health in children depends on a range of nutrients working together, and many children’s diets often fall short in ways that aren’t immediately obvious.
Why childhood is the critical window for bone building
Many people don’t know this, but bones are actually living tissue that is constantly being broken down and rebuilt, and the years between childhood and early adulthood are when the majority of bone mass is laid down. In fact, by the time most young people reach their mid-20s, around 90% of their peak bone mass has already been established.
This matters because the bone density your child builds now will influence their bone health for the rest of their life. Children and teenagers who go through this period without adequate nutritional support may reach adulthood with a lower bone density baseline, which increases their risk of fractures, osteoporosis and other bone-related issues later in life.
The good news is that small consistent changes to what your child eats can make a meaningful difference to their long-term outcomes.
Calcium is important, but it’s not the whole story
Calcium is the primary structural component of bone and without sufficient calcium, bones cannot mineralise properly and bone density suffers. So yes, calcium matters!
What is not widely known is that calcium needs a team of co-factors to actually reach the bone and do its job. Without adequate vitamin D, magnesium and vitamin K2, much of the calcium your child consumes may not be absorbed effectively or directed to where it is needed most.
Good food sources of calcium include dairy products, leafy green vegetables, tinned salmon with bones, tahini, tofu, edamame and fortified soy or plant-based milks.
One thing worth mentioning here, particularly for parents of toddlers, is that more calcium is not always better. Children who drink excessive amounts of cow's milk - typically more than 500ml per day - are at a higher risk of iron deficiency. Calcium competes with iron for absorption, and a toddler who fills up on milk throughout the day often has less appetite for the iron-rich foods their growing body needs. If your toddler is a big milk drinker and you have noticed they are pale, tired or prone to getting sick, it may be worth having their iron levels checked.
The role of magnesium in bone density
Magnesium is a critical bone-building nutrient that is needed to activate vitamin D, support calcium absorption and regulate the cells responsible for building new bone tissue. Research suggests that up to 50% of bone volume is influenced by magnesium status, but it rarely gets the attention it deserves.
Magnesium is also commonly low in children eating a typical Western diet, particularly those who eat a lot of processed food and not much in the way of vegetables, nuts or wholegrains.
Good food sources of magnesium include nuts and seeds, dark leafy greens, wholegrains, legumes and dark chocolate.
Why vitamin D and K2 work together
I often tell clients to think of Vitamin D and vitamin K2 as a delivery team for calcium. Vitamin D supports the absorption of calcium from food in the digestive tract. Vitamin K2 then directs that calcium into the bones rather than allowing it to accumulate in soft tissue.
These nutrients work most effectively in combination, and a deficiency in either one can undermine calcium's ability to do its job.
In Australia, vitamin D deficiency is more common than many people realise, particularly during the winter months when sun exposure is limited. Children who spend a lot of time indoors, have darker skin tones or live in southern states are particularly at risk of running low.
Vitamin D is found in oily fish, eggs and fortified foods, and is also produced by the skin in response to sunlight. Vitamin K2 is found in fermented foods, egg yolks, butter and some aged cheeses.
Protein - the overlooked bone-building nutrient
Protein is not something most people associate with bone health, but it definitely deserves a mention. Approximately 50% of bone volume is made up of protein, specifically collagen, which forms the structural framework that minerals like calcium and magnesium build on.
Without adequate protein, that framework is weaker, regardless of how much calcium your child is consuming. Protein is also essential for the production of growth factors that drive bone formation during childhood and adolescence.
Good food sources of protein include eggs, meat, fish, dairy, legumes, soy, nuts and seeds.
Kid-friendly meals and snacks that tick all the boxes
You don’t need to overhaul your family's meals to get these nutrients into your kids. The key is variety and consistency rather than perfection.
Here are a few simple meal ideas that naturally cover multiple bases:
Cheese and vegetable frittata - calcium from the cheese and eggs, plus protein and vitamin K2
Pasta with a creamy sauce made with milk or cream cheese, hidden spinach and chicken - calcium from the dairy and spinach, protein from the chicken
Homemade pizza on a wholegrain base with cheese, vegetables and a protein topping - calcium from the cheese and magnesium from the wholegrain base
Bean and cheese quesadillas with avocado - calcium from the cheese and beans, magnesium from the beans and avocado
Baked salmon fish cakes with a simple dip - protein, vitamin D and omega-3s in a finger food format that younger children tend to enjoy
Snacks matter too. Bone-boosting snacks include:
Cheese and wholegrain crackers — a quick and easy snack rich in calcium and protein
Hummus with vegetable sticks or wholegrain crackers — the tahini in hummus is a surprisingly good source of calcium
A smoothie with fortified milk, banana and a spoonful of peanut butter — a popular snack for children of all ages and rich in calcium, magnesium and protein
Yoghurt with fruit — calcium and protein with natural sweetness
A note on supplements
For most children eating a reasonably varied diet, food sources should be the priority. However, vitamin D supplementation is worth considering for children who have limited sun exposure, particularly through the winter months. If you are concerned that your child may not be meeting their nutritional needs through food alone, it is worth speaking with a nutritionist who can assess their individual requirements.
References
Abrams, S.A. (2021), ‘Bone health in school age children: Effects of nutritional intake on outcomes’, Frontiers in Nutrition, vol 8.
Jinnah, B. (2023), ‘A comprehensive review of minerals and vitamins synergy: Impacts on adolescent and childhood bone development’, American Journal of Health, Medicine and Nursing Practice, vol.8, no. 4, pp 12 – 30.
Prentice, A., Schoenmakers, I., Laskey, M., De Bono, S., Ginty, F., & Goldberg, G. (2006), ‘Nutrition and bone growth and development.’, Proceedings of the Nutrition Society. vol. 65, 348 - 360.