Calcium on a plant-based diet: guide to fortified milks, yoghurts and cheeses

April 22, 2022

These days, there is no shortage of plant-based milks, yoghurts and cheeses stocked throughout our supermarket shelves. However, when these take the place of dairy products, it is important to choose brands that include calcium to ensure that your diet is not lacking this essential nutrient.

 

What is calcium, and why is it important?

Calcium is a mineral that is needed for the growth and maintenance of healthy bones. As the most abundant mineral in the human body, it is mainly stored in our bones and teeth, providing them with strength and structure (1). Calcium also plays a role in muscle contraction and blood clotting, maintaining normal heart rhythm, hormone secretion and nerve signalling (2).

If we don’t get enough through our diets, the calcium stored in our bones acts as a reservoir to maintain balance throughout our blood and tissues. When needed, calcium is drawn from the bones and transported to fulfill its necessary functions. This means it is important to replenish our calcium stores to prevent bone damage and loss (3).

 

Plant-based sources of calcium

There are many plant-based foods that are natural sources of calcium, some of which have been listed in the table below, along with their calcium content per serve (4):

plant-based calcium foods

Other plant-based foods may be fortified with the mineral, such as tofu, most plant milks, many plant-based yoghurts and cheeses, some breakfast cereals, juices and breads. 

 

How to tell if a product is calcium-fortified

Fortified foods are those that have had extra nutrients added by manufacturers that don’t occur naturally in the product. 

If a food has been fortified with a vitamin or mineral, it must be listed as an ingredient on the food label. This is the easiest way to tell whether calcium has been added. Just look for the word ‘calcium’ somewhere in the ingredients list (5).

Any product that makes a claim along the lines of being a ‘good source of calcium’ also needs to include the amount of calcium added in its nutrition information panel (5).

By using the ‘quantity per 100g/mL’ column, you can look at how much calcium has been added and compare similar products. 

For example, on the nutrition panel below for Vitasoy Soy Milky, you can see it contains 120mg of calcium per 100mL.

 

nutrition panel showing calcium content of vegan vitasoy soy milky

 

For a fortified product to be considered a good alternative to dairy, it must contain at least 100mg of calcium per 100mL (or per 100g for solid foods) (6), so the above milk alternative is a good option.

In contrast, Bonsoy Soy Milk (whose nutrient panel is shown below) is fortified at much lower levels, with only 25mg of calcium per 100mL. Therefore, Bonsoy isn’t considered the best option for those who may already struggle to meet their calcium needs.

 

calcium content on nutrition panel for vegan bonsoy soy milk

 

Which plant-based yoghurts contain calcium?

Although there are now many plant-based yoghurts available, most are naturally low in calcium (and unlike plant milks, many remain unfortified). Choosing products that are calcium-fortified is the best way to ensure you are meeting your nutritional needs whilst being able to enjoy these foods as part of a well-balanced diet.

With calcium in mind, the best yoghurt options include most of the Alpro range, which are fortified with 108-140mg of calcium per 100g. The only exceptions are Alpro Greek Style With Coconut and Alpro Absolutely Oat, which are not fortified, and contain only small amounts of calcium. 

Other good calcium sources include the 150g Cocobella Yoghurt Pouches. Available in 3 flavours, these are great for a serve of calcium on the go, with 113mg per 100g. Unfortunately, the rest of the Cocobella range are not fortified, so they don’t have the same nutritional value.

Calcium-fortified yoghurts on a vegan diet - alpro, cocobella

Most other plant-based yoghurts on the market (such as Nakula, CoYo and Kingland) are not fortified, and therefore don’t make good dairy equivalents. Many of these (particularly those with a coconut base) are also high in saturated fat, which is something else to consider for these options.

 

Which plant-based cheeses contain calcium?

Plant-based cheeses are another product that have recently taken the limelight, with more and more brands appearing on our shelves. So much variety can make it hard to choose, however comparing the calcium content of these different options can make the decision much easier.

In Australia, the Made With Plants range is top tier, with all of their shredded and block cheeses boasting a whopping 720mg of calcium per 100g. These are also all quite modest in energy and have relatively low saturated fat levels, making them a great choice for all things cheesy.

calcium-fortified vegan cheese, made with plants

In contrast, other big brands like Bio Cheese and Sheese are typically unfortified, and in turn provide next to no calcium. Whilst there is nothing wrong with sometimes choosing these products, looking for alternatives with a better nutritional profile is a great way to help meet your daily requirements and get more bang for your buck.

 

What about calcium in tofu?

Tofu is often quoted as being a good plant-based source of calcium, and this isn’t just by accident. Naturally, tofu does contain a decent amount of the mineral, however, many brands boost this even further by using calcium during the setting process.

This is another instance where the Made With Plants range shines, as both their Sesame & Garlic and Teriyaki tofus are calcium-set, at 168mg and 173mg per 100g respectively. Other calcium set options include all Evergreen and TLY Tofu varieties.

calcium-set vegan tofu - TLY, Evergreen, Made with Plants

Other brands, such as Soyco and Nutrisoy, use magnesium in the setting process. This means that the calcium content is significantly lower.

However, unlike the unfortified plant milks and cheeses, even the magnesium-set tofu products still tend to have a reasonable amount of calcium – for example, 99mg per 100g in Soyco Thai Tofu. If your calcium intake is of particular concern, it might be worth it to check the ingredients list and choose calcium-set varieties to maximise your intake.

If you don’t spot ‘calcium’ listed in the ingredients list, sometimes it will be indicated with the following additive numbers: e516 – Calcium Sulphate, e170 – Calcium Carbonate & e509 – Calcium Chloride.

 

Calcium requirements on a plant-based diet

Daily calcium requirements change with gender, age and life stage, with more of the nutrient being needed during phases of bone growth (such as throughout childhood and puberty) (1).

For females, calcium requirements also increase after menopause, as the hormonal changes that take place during this time cause reduced calcium absorption and increased urinary excretion (meaning that more calcium is lost through the urine) (1).

Calcium absorption is also found to reduce with age for both sexes, so elderly men and women require greater dietary intake to maintain their bone strength as they age (1).

These typical fluctuations in calcium requirements have been outlined below, where the adequate intake (AI), estimated average requirement (EAR) and recommended dietary intake (RDI) values are represented (1):

australia nutrient reference values - calcium needs on a vegan diet by age and sex

Since the general population gets most of their calcium from dairy products, from which it is readily bioavailable, vegans and those following a plant-based diet tend to have lower intakes on average (1).

This doesn’t mean that plant-based diets cannot provide enough dietary calcium – there are plenty of plant foods that are great sources of the mineral (7). However, bioavailability is something to keep in mind, as the efficiency of calcium absorption can vary greatly between different foods (1).

To minimise the risk of deficiency, it is recommended that vegans aim to hit the RDI values, as this allows for the inevitable fact that some of the calcium eaten won’t be fully absorbed.

For all ages, calcium also has an upper level of intake (UL) value of 2500 mg/day – amounts above this could cause harmful or adverse health effects. Therefore, for both vegans and the general population, daily intake should stay below this level (1).

 

Factors affecting calcium absorption on a plant-based diet

In addition to age-related changes, there are many other factors that can affect the absorption of calcium from different foods. 

This is because calcium can only pass through the intestinal wall if it is dissolved, so its absorption depends on other substances that make it more or less soluble. 

For instance, calcium is less readily absorbed from foods that are rich in oxalic acid (e.g. spinach, beetroot, rhubarb) or phytic acid (e.g. legumes, grains, nuts, seeds) as these phytochemicals form complexes with the mineral that stop it from dissolving (2).

calcium-fortified plant milks on a vegan diet - oat milk, soy milk, almond milk

This means that even though these foods contain calcium, it is not in a form that the body can use, so it will instead be wasted.

Other substances may not impact its absorption, but will instead cause excess calcium to be lost through the urine. For example, alcohol and high sodium foods can flush calcium from the blood, causing depletion of calcium stores and in turn the breakdown of bones (1).

High protein diets can have a similar calcium-flushing effect to sodium and alcohol. However, the intake of protein alongside calcium also makes it more soluble, which increases its absorption (1). Ultimately, high protein diets do not significantly affect calcium absorption. 

In contrast, vitamin D is an essential nutrient for maintaining calcium balance and preventing deficiency, as it enables calcium absorption along the intestines (8).

Whilst vitamin D is mainly produced when the skin is exposed to sunlight, some plant-based foods are fortified with the nutrient (such as plant milks and cereals) which can help boost our levels. 

There are also some non-diet related factors that can affect our calcium absorption. For example, parathyroid hormone (a hormone released by the parathyroid glands) and exercise can enhance absorption, whereas caffeine, certain drugs (which may include prescribed medications) and stress can have the opposite effect.

 

Signs of calcium deficiency

Hypocalcemia, otherwise known as calcium deficiency disease, may occur if you are not getting enough calcium through your diet, or if the calcium being eaten is not well absorbed.

Hypocalcemia often has no symptoms, especially when only mild. However, when symptoms do develop, they may present as a wide range of signs (9):

  • Weak, brittle nails
  • Slow hair growth
  • Numbness or tingling in the hands, feet and face
  • Muscle cramps, spasms and seizures
  • Difficulty speaking/breathing
  • Confusion or memory loss

 

Calcium deficiency is also associated with the development of other conditions. The most well-known of these is osteoporosis: a disease where bones become weak and brittle with a much higher risk of fractures (2).

Whilst this condition typically develops in older age, its prevention depends on the peak bone mass that is reached in earlier adulthood. Getting enough calcium throughout all life stages is important to minimise risk later on. 

Other conditions linked to calcium deficiency include rickets in children, and osteomalacia, both of which are marked by the softening of bones (2).

 

Does following a plant-based diet put me at risk of calcium deficiency?

For those following a plant-based diet, there isn’t an equivalent food item that compares to dairy when looking at affordability, calcium content and bioavailability. Due to this, vegans and plant-based eaters do tend to eat less calcium as a whole, which puts many at risk of deficiency (1).

However, there are still plenty of plant-based calcium sources, meaning its intake can be adequate in a well-balanced, plant-based diet. It may just take more consideration and careful planning than it would for non-vegans (7).

In saying that, vegans are not the only ones who should be concerned about deficiency. In fact, more than 50% of Australians get less than enough of the mineral through their diet, suggesting that many people should consider whether they are getting enough calcium (10).

 

Should I supplement calcium on a plant-based diet?

Not everyone following a plant-based diet will need to take a calcium supplement. However, for those who struggle to meet their daily requirements through diet alone, supplementing may be a useful way to help bridge the gap.

When it comes to calcium supplements, not all are made equal, with different calcium compounds and amounts being used. However, as a general rule, it is found that calcium is best absorbed when taken in small doses (500mg or less), several times throughout the day (2).

Having too much calcium can also have negative effects, with high doses being linked to stomach pains and bloating, kidney stones and increased heart disease risk (2).

Some calcium supplements may also include vitamin D as they work together to support bone health.

As such, it is recommended to chat to your doctor and/or dietitian who can give you informed and personalised advice about whether to supplement.

 

choline supplements - capsule, tablets, pills

 

The bottom line

Calcium is a mineral that is essential in our diet for healthy bone growth and maintenance, as well as playing important roles in many other systems. 

As the general population gets most of their calcium from dairy products, people following a plant-based diet tend to have lower calcium intake. However, there are plenty of plant-based foods that naturally contain calcium, and several more that are fortified. 

When considering plant-based milks, yoghurts and cheeses, choosing options that are fortified with more than 100mg of calcium per 100mL or 100g is a great way to bump up your intake and lower your risk of calcium deficiency.

Taking a calcium supplement may also be beneficial, however, it is important to get individual nutrition advice from a qualified professional before doing this to make sure it is the right choice for you.

If you feel that you might not be meeting your nutrient needs on a vegan or plant-based diet, you can can book an appointment with one of our dietitians at the PNW Clinic for personalised guidance and support.

 

References

  1. Calcium – Nutrient Reference Values for Australia and New Zealand
  2. NIH Calcium Fact Sheet for Health Professionals
  3. Overview of Calcium
  4. Australian Food Composition Database – FSANZ
  5. Vitamins and Minerals Added to Food – FSANZ
  6. Eat For Health Educator Guide
  7. Nutritional Update for Physicians: Plant-Based Diets
  8. Calcium and Vitamin D: Important at Every Age
  9. Hypocalcemia
  10. Australian Health Survey: Usual Nutrient Intakes – ABS

 

This article was co-written by student dietitian Megan Keith and PNW Clinic dietitian Megan Boswell.