What is calcium?

vegan calcium guide

First, we need to understand what calcium is and the role it plays in the body.

Calcium is a mineral found everywhere on earth and is one of the most abundant minerals found in the earth’s crust.

Its located in the plants that sprout all over the globe, found in the many rock formations that you may pass while walking idly by on the beach,

And speaking of beaches, its located in the shells of many sea creatures.

Calcium is found EVERYWHERE, and as you may not be surprised to now hear, calcium is found abundantly in our human bodies. 

In fact, calcium is the most abundant mineral in our human body, with over 99% of it found in our bones and teeth

On the periodic table, calcium takes the form Ca, has an atomic number of 20 and is classified as an alkaline earth metal

Since calcium is an element rarely found unattached to another element, there ends up being many forms of calcium out there.

The main form of calcium found in our bones is Calcium phosphate with the average-sized human carrying around 1kg of this mineral everywhere they go 

What role does calcium play in our bodies?

Benefits of calcium

As many know, calcium is vital to the building of healthy teeth and bones, but this isn’t its only role. Its also used for

benefits of calcium

Nearly all the calcium found in our bodies is contained in our bones and teeth and with calcium playing such a vital role in the healthy functioning of our body you may be surprised to hear that less than 1% of that calcium supply is needed for these functions to keep running.

The rest of the calcium is used to maintain strong and healthy bones while simultaneously being used as a calcium storage stash to keep a constant supply cycling from our bones into our blood and muscles. 

The biggest thing to take note of here is that even though our bodies are loaded to the brim with calcium, we cant actually produce calcium ourselves.

Our bones go through a constant process of calcium extraction and bone reformation in a continuous cycle as and when needed, but seeing as we cant create the calcium ourselves, we need to keep a regular top-up from an external source. 

This is where calcium from nutrition comes in.

Where does it come from?

  • Unfortunately, some still believe calcium is only found in the special milk of one famous animal known as a cow, which is far from correct. As mentioned earlier, calcium is found everywhere on the earth, so it makes logical sense to realize calcium can also be found in things that grow from the earth. 

Main vegan sources of calcium

calcium foods

In the typical western diet, calcium intake is mainly found in the dairy they consume predominantly in cows milk, yogurt, and cheeses.

There are many vegan foods high in calcium that you can add to your diet. Below are some of the best that provide a high percentage of calcium per 100 grams.

  • Bok choy
  • Mustard greens
  • Tofu
  • Tempeh
  • Brocolli
  • Fortified foods
    • Soy milk
    • Almond milk
    • Fortified tofu
    • Fortified cereals

Check out the top 12 vegan foods high in calcium that you can add to your diet for a healthy nutritional boost without dairy.


A healthy plant-based calcium supplement can be a great addition to a balanced diet that can make up for any nutritional inefficiencies and to ensure the recommended daily amount is met. There are some great vegan calcium supplement options available that can work for a variety of situations, whether you are new to the vegan diet or a vegan fitness enthusiast trying to hit specific nutrient numbers. (link to commercial calcium article)

An alternative to a calcium focussed supplement is a plant-based multivitamin that contains calcium as well as a host of other essential nutrients needed on the vegan diet such as zinc, iron, b12 and vitamin d to name a few.

Key factors that affect calcium absorption

5 factos that affect calcium absorption

Calcium absorption rates and bioavailability will differ based on the food source and the ratio of calcium to other essential minerals like magnesium and iron that are contained within that food source. Below are the average absorption rates for popular calcium food sources for both vegans and vegetarians.

  • Dairy sources
    • High absorbability(~32%): Milk, cheese, yogurt
  • Plant-based sources
    • High absorbability(32-80%): Kale, bok choy, broccoli, soybeans 
    • Medium absorbability(~25%): sweet potatoes
    • Low absorbability(~5%): spinach 

Calcium Absorbability – Calcium co-factors

Vitamin D

  • Vitamin D is one of the most crucial cofactors when it comes to calcium. Sufficient vitamin d intake either from the sun or from food is paramount to optimal calcium absorption and the maintenance of healthy bones. A lack of vitamin d can make a lot of nutritionally consumed calcium be wasted since your body doesn’t have the necessary components to make use of this externally added calcium.


  • Magnesium is another mineral that plays a pivotal role in the calcium extraction and reformation cycles and how strong our bones are. Magnesium is needed for healthy bone formation, for protein synthesis and the effective metabolizing of energy. Although there is a synergy between calcium, vitamin d, and magnesium, studies show that magnesium and calcium may compete when it comes to absorption. A large amount of magnesium consumed simultaneously with calcium can hinder how much calcium is absorbed. A 2:1 ratio of calcium to magnesium can help with any intake issues or simply having high magnesium meals/supplements at a separate time to high calcium meals/supplements.

Vitamin K

  • Another vitamin that is less widely talked about but still plays a significant part in the calcium equation. Vitamin k plays a crucial role in bone metabolism, the clotting of blood for healing, and the regulation of blood calcium levels.
  • It helps to prevent calcification in the arteries which can occur from having too much calcium
  • So efficient vitamin k intake can help to prevent overdoses of calcium.


  • Excess protein has been linked to an increase in calcium excretion through urine, which many believed caused more calcium to be extracted from bones to balance out the acidity, therefore, leaving you with weaker bones but evidence. shown that the adverse effects of increased acid load due to high protein consumption are balanced out by the beneficial skeletal effects gained from the high protein intake
  • Recent studies have also shown protein is beneficial to calcium utilization 
  • A question to ponder is what effects outside of bone health does an increase in acid load through excessive meat, and protein intake have on the body?
  • Overall the general consensus is getting a healthy dose of plant-based protein without overdoing it will help to balance the calcium you take in and may even make your bones stronger.
5 factos that affect calcium absorption

Foods and Nutrients that can hinder calcium absorption

  • Sodium, Alcohol, Caffeine (Coffee and Tea)
  • Phytic acid
  • Oxalates
    • Not all plant-based foods are created equally when it comes to calcium, and one of the factors that differentiate one source of calciium from another is the level of oxalates contained within. Although there is debate on how much of an effect oxalates have on calcium absorption, studies have shown that the higher the amount of oxalate in the food source, the lower the overall absorption rate.

Is dairy a better calcium source than plant based alternatives?

The bioavailability of calcium from cows milk is overall higher than plant based options like kale and spinach due to the lower amount of oxalates and phytates contained within but does this make it a better choice for humans to use on a regular basis?

Lets analyse the data and see what conclusions we can make.

  • Dairy products are one of the main causes of clogged arteries in the western diet which is also linked to high cholesterol
  • High cholesterol causes heart disease which is the number one cause of death in America 
  • Dairy is also associated with prostate, lung, breast, and ovarian cancer. 
  • Lactose intolerance is more common than many realize, especially in America, with it affecting from 50-90% of most races. The high rate of lactose intolerance is due to many humans losing the ability to create the enzymes needed to break down sugars found in cow and breast milk, which we initially required as babies growing up but no longer have use for in adult age.
  • Plants do not contain lactose, so the issues that occur through dairy consumption will not occur when using plant-based forms of calcium.

How does the production of dairy effect the environment, animals, and sustainability

Staggering amounts of evidence 1,2,3,4,5.6. show that the number of resources needed to grow and maintain plant-based forms of calcium is tiny in comparison to the number of environmental resources the dairy industry needs to keep up production.

Taking an unbiased look at the actual statistics, it is pretty evident that plant-based alternatives to dairy take less of a toll on the planet not to mention the drastic decrease in animal death & cruelty that can occur when choosing plant production over dairy production.

The main things that can cause a vegan calcium absorption issues

  • Lack of knowledge of the right food sources and consuming an overall unbalanced diet
  • Picking food sources with low calcium content
  • Selecting food sources with high phytic acid and oxalates 

How to avoid these issues

  • Consume a balanced plant based diet with a variety of food sources
  • minimise processed foods while learning which vegan calcium food sources are best to consume
  • If consuming foods with high levels of phytic acid, learn to cook these foods since this lowers the overall level of phytic acid allowing calcium to be more easily absorbed

How much calcium do we need, and what external factors can change the requirement?

The recommended daily amount is around 1000-1300mg for both men and women but varies depending on a few things.


  • The phase of a human being’s life will determine how much calcium their body requires to be running at an efficient level. As a baby till your first birthday, you require only around 200-260mg of calcium per day, but as you rise in age and keep growing, your body continually demands more peaking in teenage life needing around 1300mg per day.
  • After puberty, our calcium demand stabilizes for both men and women at 1000mg until 50 years old, where the calcium demand for men stays pretty stagnant but increases for women due to menopause.

Activity levels

For a sedentary person, the general guidelines for calcium are perfect, but studies have shown that for high endurance athletes the calcium requirement may increase with intensity levels

Athlete (calcium levels and its effects on athletic performance)

Calcium is classed as one of the most significant nutrients in an endurance athletes regime

and rightly so, since excessive exercise can cause a strain on your muscles and bones, it is crucial to keep the strength and integrity of your bones intact by maintaining a sufficient supply of calcium in your bloodstream and bones.

Studies have also shown that high-intensity interval training and endurance training can cause urinary calcium increase and serum calcium decreasing which may have the potential to cause osteoporosis in the longterm, so it is essential for athletes especially to get an adequate supply of calcium daily

The amount required will still vary depending on gender, age, and exercise intensity but an average between 1000-1500 is optimal.

How can I tell if I’m calcium deficient?

signs of calicum deficiency

Since calcium plays such an important part in so many of our bodily functions, it is important to be aware of some of the symptoms that could be linked to a possible calcium deficiency. 

  • Some symptoms to look out for:
    • Tiredness and fatigue
    • Depression
    • Weak nails
    • Brittle bones and hair
    • Muscle spasms
    • Memory loss
    • Low blood pressure
    • If you notice any of these signs, consult your doctor.

Can you have too much calcium?

Although calcium is a relatively safe mineral, its essential to know the range in which you need to stay within to maintain health and avoid any issues.

The upper intake limit of calcium according to the institute of medicine of the national academies is: 

  • Adults 19-50 = 2,500 mg/day upper intake limit
  • Adults 51 and above = 2,000 mg/day upper intake limit
  • Pregnant or lactating aged 14-18 = 3,000 mg/day upper intake limit
  • Pregnant or lactating aged 19-50 = 2,500 mg/day upper intake limit

*data references*

In cases with extremely high levels of calcium, it has the potential to impair iron absorption

Since there is so much misinformation out there stating that vegans can’t get enough calcium from their diet, some people who may not currently have the right knowledge may mismanage their calcium intake by taking excessive supplements and boosting their calcium intake way above the upper intake limit.

Vegan calcium supplements can be a great way to bring nutritional balance to a plant-based diet, but they shouldn’t be your sole source of calcium. Whole plant-based foods should always be your first option for calcium intake.

Is high calcium percentage a good enough factor in deciding whether a food is optimal for calcium intake?

Studies have shown that calcium on its own is not the most significant factor for the prevention of bone fractures, so consuming a ton of milk is not the answer. The reality is nutritional Calcium intake is one of many things needed in the equation for calcium balance and healthy bones over the longterm.

Protein, Vitamin d, magnesium, vitamin k, and regular exercise are the other components necessary for maintaining healthy bones.

Dairy is usually promoted as a way to build healthy bones due to its large and highly absorbable calcium content, but the issue is the longterm adverse effects on the body through using dairy as a calcium source, and that’s without even addressing the long term effects on the planet. 

Phytic acid/oxalic acid and “convenience” are the two things that someone may use in defense of dairy over plants for calcium but when you look at the bigger picture these are simply a food balance and mindset issue that can easily be overcome with the right knowledge

  • Eat a balanced diet consisting of plants with a high calcium content 
  • Use fortified plant-based foods

Vegan calcium conlcusion

So, are vegans able to obtain enough calcium without the consumption of dairy?

  • The short answer is Yes, but some basic requirements are needed to make the process as smooth as possible and avoid potential deficiencies in the future
  • Balance out your diet with healthy plant-based foods that have a high amount of highly absorbable calcium.
  • The key is balance. Pay attention to the list of foods that are high in calcium and take note of how much calcium they provide. Your aim is to hit your calcium target daily
  • Some people get put off when they think of possible lower absorption rates for plant-based calcium sources, but a balanced diet with a variety of calcium sources should cover most calcium intake issues
  • For those who want more precision in their diet Focus on foods with lower phytic and oxalic acid
  • Plant-based Calcium supplements are another alternative that can be used to support a balanced diet but not to replace a balanced diet (link to top vegan calcium supplements)
  • Calcium-fortified foods 

Side note to remember when analyzing food data and labels. The RDA and RV are already taken into account the higher or lower absorption rates for the food that you are analyzing, so you do not need to recalculate absorption after reading these numbers. So as long as your plant-based choices allow you to hit the recommended daily amount of calcium, your calcium levels should be fine.

The reality is both vegans, and dairy consumers can get their recommended calcium requirement from their choice of foods with some simple knowledge on the right high calcium foods to consume. A stumbling block for some will occur when transitioning from a typical western diet to a vegan one and not knowing which foods to consume.

Once you know which ones provide the nutrients you need in any given situation, the health benefits end up being endless.

The most significant benefit of choosing plants as their calcium source is the avoidance of future serious diseases. Dairy is linked to many serious illnesses such as heart disease and various cancers. In contrast, the amount of serious illnesses that occur from a balanced variety of high calcium plants, fruits, and vegetables is slim to none.

The other obvious benefit of plant-based calcium over dairy is that no animals need to be harmed for you to get your calcium, and there is less toll on the environment as a whole. 

With the information provided it seems pretty clear that the “vegans are unable to get calcium without cows milk” story is nothing but a myth and can be happily put to bed and tucked in nicely never to be woken up again 🙂


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