When you’re new to a whole food plant-based diet, it’s a common thing to wonder whether you will get all the nutrients you need. After all, the dairy industry has been telling us for years that we need to consume multiple servings of dairy products a day in order to grow and maintain strong bones. This leaves many wondering how they will meet their calcium needs on a diet that excludes dairy products. To ease your mind, this post is all about calcium. How much you need, where to get it, and comparing plant-based sources to animal-based sources. Let’s get to it!
How Much Calcium Do You Need?
The Dietitians of Canada recommend daily intake (RDI) of 1000mg for those between the ages of 19 and 50. For adults over the age of 51, the RDI increases to 1200mg a day. For pregnant and lactating women, the recommendation is 1300mg per day.
However, it’s important to remember that these recommendations are made at a level that will ensure everyone gets more than they need. As such, RDI amounts are generally significantly higher than what we truly require.
When you’re eating a plant-based diet, you don’t have to worry about the calcium loss experienced by consumption of animal products (more on that later). Due to this, the dietary requirement is actually lower. Some studies show this could be as low as 500-750mg per day. If you follow Dr. Greger of nutritionfacts.org, he recommends at least 600mg per day from calcium-rich plant foods.
Absorption
How much calcium we consume is one thing, but how much we actually absorb is another. There are a few things affecting the absorption of calcium in our bodies that we need to talk about.
One factor is a safety mechanism of sorts. You see, our bodies work to protect us from getting too much by blocking absorption when intake is high. This keeps us from hypercalcemia or too much calcium. Alternatively, the body also works to better absorb calcium in the intestines when intake is low. Helping us get the most we can from the food we eat.
The bioavailability of calcium in a food item is also an important factor in absorption rates. Bioavailability refers to how available a compound is for absorption. Some foods may appear high in calcium, but it may not be as bioavailable as others. For example, spinach contains ample levels of calcium, but it is also high in oxalic acid or oxalates. The oxalates bind with the calcium in the spinach, reducing the amount actually available for absorption. As such, high oxalate greens like spinach, beet greens and swiss chard, are not ideal sources. They have many other important nutrients though, so don’t think that you should avoid them altogether.
To give you an idea, in terms of bioavailability, absorption rates of calcium from cow’s milk is only about 30%. Compared to about 31% for tofu, and about 50-60% for vegetables like bok choy, broccoli and kale. This means that vegetables are actually a better source of calcium than dairy products.
Other Factors Affecting Absorption
It’s always important to remember that nutrients and compounds found in plant foods do not act alone. They work with other nutrients and compounds to take care of all of our complex processes. In the case of calcium absorption and use, magnesium, vitamin D and vitamin K all play important roles.
Magnesium is important to both calcium absorption and bone formation. It also aids the body in utilizing vitamin D, so it’s an important nutrient for bone health. You can get magnesium from whole grains, green leafy vegetables, nuts and seeds, legumes, fruits like figs, bananas and raspberries and veggies like brussels sprouts, green beans, peas, broccoli, cabbage, asparagus and artichokes.
Vitamin D is also important to calcium absorption and bone formation. Without sufficient vitamin D, you can only absorb about 10-15% of dietary calcium. Vitamin D can be tricky to get from food sources reliably. It’s typically only found in mushrooms that are exposed to UV lights and fortified foods (like non-dairy milk and cereals). You can also get vitamin D by exposing your skin to sunshine, but this becomes difficult to do in the colder, darker, winter months. The most reliable source is to supplement with 2000 IU a day (for adults).
Vitamin K has an important role in calcium utilization. It works in a couple of different ways to help proteins bind to calcium so it can be transported through the body to where it’s needed. It also plays a role in helping calcium actually bind to bones. Vitamin K is found in dark green leafy vegetables like kale and collard greens, as well as vegetables like brussels sprouts, broccoli, cabbage and cauliflower.
Dairy as a Source of Calcium
When looking at dietary sources of calcium, it’s important to consider the quality. What else is contained in that particular food?
In terms of dairy milk, yes, it contains calcium, but that comes packaged with a bunch of things you don’t want in your diet.
Hormones are present in all dairy milk, as breast milk is a hormonal fluid. Cow’s milk is simply breast milk produced by cows, formulated to grow a baby calf into a 500lb cow in about a year’s time.
It also contains saturated fat and cholesterol, which are linked to increased risk of cardiovascular disease as well as other health issues.
Not to mention the other substances found in dairy products, which include pus, antibiotics, lactose (which the many are intolerant to) and pesticides.
“Drinking milk for nutrients is like inhaling cigarette smoke for oxygen”
-Dr Milton Mills
The primary source of protein in dairy milk, casein, is also problematic. It has been shown to be an aggressive cancer promoter. This was found in Dr. T Colin Campbell’s study on rats. He found that rats fed a 20% casein diet developed more liver tumours and pre-cancerous lesions than the group fed a 5% casein diet. Further to this, he found that switching the 20% group to a 5% diet, had a marked improvement on their tumours. While switching the 5% group to a 20% diet led to a significant worsening of tumours. Essentially, he was turning the cancer on and off by raising or lowering the amount of this protein they consumed.
Dairy products are also linked to increased risk of autoimmune disorders including type 1 diabetes and multiple sclerosis.
If you can get past all of that, you should also know that dairy foods tend to be very acidic and acid-forming in the body. This contributes to a pH imbalance, which the body has to correct by leaching calcium from our bones. So, consuming dairy products for calcium is not actually beneficial.
Plants as a Source of Calcium
Thankfully, there are plenty of plant-based sources to choose from. Calcium is a mineral found in the soil. So instead of consuming it from animal products, we can get it from the same place the animals do, plants. The great thing about plant-based sources of calcium is they come without all of the harmful substances found in dairy products. Plus, they are alkalizing, so there’s no risk of bone loss from correcting the pH balance like we see in dairy sources.
As an added bonus, the calcium in green leafy vegetables like kale, broccoli and bok choy is absorbed about twice as well as that in cow’s milk. They also come packaged with other important nutrients like vitamin K (important for bones as mentioned above) iron, folate and protective antioxidants.
That’s the kind of nutrient sources you want to focus on. Choose the ones that come packaged with beneficial nutrients and compounds, instead of harmful components.
Plant-Based Sources
Here are some great plant-based sources of calcium:
Vegetables:
(Amounts listed are per ½ cup, cooked)
Collard Greens – 189mg
Turnip Greens – 130mg
Kale – 95mg
Bok Choy – 80mg
Okra – 60mg
Broccoli Raab (AKA Rapini) – 50mg
Acorn Squash – 45mg
Butternut squash – 42mg
Sweet Potato – 40mg
Broccoli – 32mg
Brussels Sprouts – 30mg
Nuts and Seeds
(Amounts listed are per ½ cup unless otherwise noted)
Almonds – 195mg
Walnuts – 60mg
Sunflower Seeds – 55mg
Chia Seeds (1 tbsp) – 90mg
Sesame seeds (1 tbsp) – 85mg
Tahini (1 tbsp) – 65mg
Almond butter (1 tbsp) – 55mg
Grains
(Amounts listed are per ½ cup cooked)
Amaranth – 135mg
Quinoa – 50mg
Non-Dairy Milk
(Amounts listed are per cup)
Soy Milk (fortified) – 320mg
Rice Milk (fortified) – 320mg
Almond Milk (fortified) – 310mg
Cashew Milk (fortified) – 220-300mg
Alternatives
(Amounts are per ½ cup cooked unless otherwise specified)
Tofu – 275-800mg (depending on the type and set)
Tempeh – 95mg
White Beans – 80mg
Black Beans – 50mg
Edamame (raw) – 50mg
Chickpeas – 40mg
Other
Blackstrap Molasses – 175mg / 1 tbsp
Dried Figs – 241mg / cup
Prickly Pears – 83mg /cup
Oranges – 72mg /cup
For Good Bone Health
For optimum bone health, you should not only consume calcium, but you need to keep it in your bones. You can reduce calcium loss and promote healthy bones by doing a few simple things:
- Avoid high protein diets – High protein intake leads to increased calcium secretion in the urine. Especially so for calcium from animal sources.
- Reduce your sodium intake – Sodium contributes to calcium loss. For every 1000mg of sodium the kidneys excrete, you lose 40-60mg of calcium with it.
- Limit Caffeine – Caffeine acts as a diuretic and pulls calcium out, causing it to be excreted in the urine.
- Exercise – Weight-bearing exercise promotes healthy bone growth and maintenance.
The Bottom Line
Don’t fall for the hype that you need dairy products for strong bones. It’s a great marketing ploy, but it’s simply not true. You can get all the calcium you need from plant-based sources. In fact, many are far superior to dairy products in content and absorbability. In a study done comparing bone density, it showed long-time vegans had the same bone density levels as omnivores, despite much lower dietary calcium intake. So you can rest assured that the plant kingdom has you covered.
Related Posts
A Plant-Based Diet – The Basics
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Great article Paula!! Tweeted!!
Thank you Heidi! So glad you enjoyed it!