The calcium debate is always a hot topic. People are still uncertain if they can meet all their calcium needs just by eating plants. Since we were kids, we were conditioned to consume dairy for calcium. The idea that dairy is necessary is well established in our heads.
Here’s the problem. We don’t know much about nutrition.
Do you know how much calcium you really need? Or how calcium is absorbed in your body? Did you know that plant foods contain large amounts of calcium?
The recommended allowance (RDA) for calcium is 1,000 to 2,000 milligrams per day for most adults. These requirements are a bit high because our modern diets have a negative effect on the amount of calcium we excrete every day. That means that we need to consume more calcium in order to make up for the calcium loss.
Different factors influence calcium loss, like the amount of protein and salt we consume. Plant-based diets that are low in sodium (and caffeine) tend to have a much lower excretion rate than the standard American diet. This means that eating vegan actually lowers your calcium needs.
A study published in the American Journal of Clinical Nutrition demonstrated that people “with low, but nutritionally adequate intake of sodium and protein may have calcium requirements as low as 500-741mg/day.”
Is there enough calcium in a vegan diet?
Calcium is an essential mineral found in the soil, just like iron, potassium and magnesium. These minerals are absorbed by the roots of the plants, and the animals get their calcium by eating these plants.
Since childhood, we have been conditioned to believe that calcium comes from dairy products when in reality, calcium comes from the earth. Animals get their calcium directly from the source and use it for diverse body functions, just like us.
The only reason why dairy is rich in calcium, is because cows are fed calcium. There is no need to consume dairy when we have all those plants available for us. A vegan diet offers plenty of calcium. A deficiency is impossible if you eat a balanced vegan diet.
A diet that is composed of a variety of vegetables, starches, and fruits provides enough calcium to meet your daily needs. Even if you eat a low-calcium diet (about 420 mg/day), studies show that your intestines will start absorbing calcium more efficiently, and your kidneys will conserve it better.
The same goes with someone who consumes too much calcium (1,740 mg/day). The body will adjust by blocking the calcium absorption and boosting excretion. This is a normal protection mechanism. Excess calcium would result in deposits in our soft tissues (heart, kidneys, skin, and muscles) and would make us susceptible to illness.
The amount of calcium that we get from food is not absorbed completely by our body. Only a small percentage of this calcium is bioavailable, so we must take that into consideration. For example, 1 cup of milk contains 300 mg of calcium, but only 90 mg will be absorbed.
Eating 1/2 cup of Chinese mustard greens, 1 cup of bok choy, 1,5 cups of kale or 2 cups of broccoli will provide you with the same amount of calcium than a glass of milk, due to their higher absorption rate (in the 40 to 60% range!).
Tofu has the same absorption rate than milk. Adding 1/2 cup of tofu to your dinner will provide you with 90 mg of calcium, with a few advantages. Unlike dairy, tofu is deprived of cholesterol. It contains more protein, less fat and sodium, making it a healthier food choice than any dairy products.
Having strong bones depends more on the prevention of calcium loss from our body than our calcium intake. Every day, we lose calcium through urine, feces and sweat. This calcium is renewed from our bones and from our diet.
Most of the calcium in our body is found in our bones, which are constantly broken down and made anew. After the age of 30, our bones tend to break down more than build up, because of calcium loss.
While we don’t absorb all the calcium in the food we eat, we also lose calcium because of different factors. Many elements can contribute to the loss of calcium. Some people tend to lose more calcium than others, like older people and individuals with low vitamin D levels.
The type of food you eat also plays a role in the amount of calcium you lose. Sodium, caffeine and protein are the main factors for calcium loss. When you consume acid forming foods, the body uses calcium to buffer that acidity. Calcium is pulled out of the bones and sent to the bloodstream. Once the pH is normalized, the calcium is lost through urination.
Sodium is the worse! The more you eat sodium, the more you lose calcium. For each 1000 mg of sodium that is eliminated by your kidneys, about 40 to 60 mg of calcium is lost through the urine. Reducing your salt intake to 1-2 grams daily will allow you to hold onto your calcium better.
Caffeine acts as a diuretic and affects our body’s ability to retain the calcium we get from food. Drinking any caffeinated beverages will pull out calcium from the body.
The more you eat protein, the more you will lose calcium through urination. If you double your intake of protein, your calcium loss will also double. Animal protein is more likely to pull calcium out of the bones than plant protein. That includes meat, fish, eggs and dairy products.
What is interesting about dairy products, is that we were always told that they are the best source of calcium for us. In fact, we are told that dairy is the only good source of calcium! In reality, we lose about 1/3 of the calcium we get from milk and more than 2/3 of the calcium we get from cheese.
Best vegan calcium sources
It is best to choose leafy green vegetables and legumes as our primary source of calcium. They provide us with lots of bioavailable minerals, without causing any calcium loss. Here are some calcium-rich foods in the plant kingdom:
- Mustard greens
- Brussel sprouts
- Sweet potatoes
- Soy milk (fortified)
- Navy beans
- Black turtle beans
- Pinto beans
- White beans
- Rice milk (fortified)
Here are a few easy, healthy and yummy calcium-rich vegan recipes:
Maintaining strong bones
Some of our lifestyle choices also play a role in the maintenance of healthy bones. Smoking increases the loss of calcium, while eating lots of fruits and vegetables helps to keep the calcium in our bones. Exposing ourselves to 15 minutes of sunlight daily permits the body to make vitamin D, a bone-building hormone. If you get too little exposure, you should supplement with 600 IU of vitamin D daily.
The present calcium intake recommendations are high because animal protein, salt, tobacco and our physical inactivity lead us to rapid calcium loss. If you eat well, avoid salt, tobacco and caffeine, and if you exercise regularly, you should be able to keep the calcium in your bones and avoid osteoporosis in your older days.
So now I turn to you…
How would you qualify your diet? What are your favourite calcium-rich foods?