If you believe everything you see on TV, you might be of the opinion dairy is the only reliable source of calcium for growing kids.
But what about those who are allergic or intolerant to dairy? How do we cover their calcium needs if they can’t handle the white stuff?
There are other sources of quality, bioavailable calcium. One of my favourites is tinned salmon- but you need to keep the bones in! The skeletal system is where the good stuff is found- just crush it up with a fork or spoon and stir through the fish.
Other sources are tinned sardines, mussels, snapper, oysters, tahini, nuts and seeds, broccoli and green leafy vegetables such as kale, collard greens, spinach, beetroot greens and bok choy. For the non-paleo tribes, tofu is another rich source, as are some legumes such as chickpeas. (Whether you choose to eat soy based products is up to you but I'd be cherry picking data if I didn't list it as a source, as bioavailability studies suggest its as well absorbed as dairy sources).
Here's a table I did up summarising the estimated calcium content of common foods. Dairy sources are at the top to serve as a point of reference and comparison. Check out those fish sources- pretty good yeah?
An important thing to note is that any table displaying the estimated calcium content of a food is simply tells us the calcium present in the food, it does not tell you how well much of the calcium you can potentially absorb. Oxalates and phytates found in high amounts in some plant based foods bind to calcium, meaning less is able to be absorbed, and you need to eat a much higher amount of these foods to cover your needs. Our gut health as well the availability of other minerals and co-factors essential to calcium absorption also affecet how much we take up from any given food.
What about bone broth?
Bone broth is often reputed to be a rich source of calcium, especially among paleo circles. However more recent research suggests it has significantly less that first thought, and varies significantly between batches (roughly 9-14 mg, a bit more if your have vegetables in your broth too).
So does this means it's not helpful? Absolutely not. While you wouldn't rely on broth alone for calcium intake, it's is still very supportive for bone health, supplying trace minerals as well as collagen. Our bones are actually 25-30% collagen proteins by weight and studies indicate the quality of the collagen matrix is vital to the strength of our bones.
Bone health is not just about calcium
Vitamin A, D, K2 and magnesium are all important factors in calcium absorption, utilisation and overall bone health. These nutrients are often much higher in those eating a wholefoods, nose-to-tail diet.
What about supplements? Can’t I just give them a little extra and be done with it?
There's still quite a bit of debate around the long term safety of calcium supplementation, especially cheaper, less bioavailable forms given in isolation. The concern is that without the very important co-factors, calcium can build up within the vascular system and increase the risk of cardiovascular disease.
Nature has it right again- we need a balance of minerals for health (bone health included) and huge amounts of a few we've singled out really just doesn't make sense.
For more support with bone health, or in getting your child eating in a balanced, nutrient-rich way book here.