Calcium is the most abundant mineral in the human body, with 99% of it stored in the bones and teeth, and around 1% circulating in the blood and tissues. On top of its role in skeletal health, calcium is required for a number of essential functions in your body, including:
the regulation of muscles contracting and relaxing
the regulation of heart function
involvement in blood clotting
involvement in the transmission of nerve signals
Cow's milk, a rich source of calcium
This is why cows milk is rich in calcium... Plants obtain calcium from the ground, and cows eat loads of grass over the day, every day. The calcium from the consumed grass in turn ends up in the cow and its milk, which is why cows milk and related dairy products are so rich in calcium (e.g. 300mg per cup).
Therefore if you consume calcium rich dairy foods, it can be easier to meet your calcium needs.
But you can still meet your calcium needs without consuming dairy...
Whether you avoid dairy because of digestive issues, ethical reasons, or something else, it's important to understand what you might be missing out on, as well as where to seek alternative sources of essential nutrients such as calcium.
There are now a lot of plant-based milk alternatives on the market, such as soy, oat, almond, rice, pea coconut and macadamia milks. Although these plant milks offer unique nutrient profiles, majority are low in calcium. You must remember this!
Macadamia milk - This creamy nut milk has a higher percentage of healthy fats compared to most other plant milks. Unlike soymilk, its protein content is very low, and unless fortified, it doesn’t contain much calcium.
Almond milk - Unlike it’s pre-processed nuts, almond milk is low in calcium, protein and fibre, and although it’s low in calories, it can really only boast nutritional benefits if it has been fortified.
Oat milk - Oats contain beta-glucan, a type of soluble fibre that can contribute to improved cholesterol levels and improve heart health. Unless fortified, oat milks are very low in calcium. Unlike some of the other plant-milks, this milk is often a good alternative for those with a number of food allergies.
Coconut milk - Is high in saturated fats, the type that increase your unhealthy cholesterol. Compared to other plant milk alternatives, it falls short on the recommendation list.
Pea milk - Most pea milks are rich in calcium and protein, as well as have a lot less sugar than other plant milks (e.g. rice and almond milks). Again, this milk alternative is really only a good source of calcium if it has been fortified.
In a nut-shell...
Most alternative plant milks are very low in calcium. However, you can purchase those that have been fortified with calcium (meaning, the mineral has been added in). If fortified, a lot of these alternative plant milks will provide similar amounts of calcium to that of cows milk.
>19 yrs old, need 1000mg calcium each day
>70yrs old, need 1300mg calcium each day
19-50yrs old, need 1000mg calcium each day
> 50 yrs old, need 1300mg calcium each day
On top of considering the amount of calcium you need to meet your daily requirements, it's also important to understand that their are a number of factors that affect the absorption of your calcium, as well as note that you can only absorb about 500mg of calcium at any one time. And absorption decreases with age.
Helpers for calcium absorption
Vitamin D plays a major role in calcium absorption through its role in the active calcium transporters in your gut. If you don’t get enough Vitamin D, your calcium absorption can be compromised. Vitamin D is noted as the ‘sun and seafood’ vitamin, which means you get most of it from the sun, as well obtain good amounts from seafood. In regard to plant-based sources, vitamin D can be obtained from certain mushrooms, as well some products that have been fortified with this important nutrient, including soy-products, plant-milks, plant-spreads (e.g. nuttelex).
Inhibitors of calcium absorption
Phytates, compounds found in nuts, seeds, wholegrains and bran, can reduce calcium absorption to a minor extent. This can be reduced by soaking, sprouting, leavening and fermenting the above mentioned foods.
Oxalates, another compound found in leafy greens, nuts, seeds, cocoa and fruits, may also somewhat inhibit calcium absorption.
Other factors that affect your calcium levels
A high-salt diet
Excess coffee and tea intake (greater than 6 cups per day)
Excess alcohol consumption
Excess soft drink / soda consumption
Excess dietary protein
Not getting enough exercise
Not getting enough sun exposure
Good sources of calcium
Green leafy vegetables
e.g. broccoli, cabbage, spinach, collard greens, herbs like parsley.
Nuts & seeds
e.g. almonds, brazil nuts, sesame seeds
Soy foods – tempeh & tofu (100g) = 100-300mg
Baked Beans (3/4cup) = 100mg
Salmon/sardines canned with bones (75g) = 200-300mg