Who hasn’t heard the old myth that we need milk for calcium? How come it’s so deeply embedded in our society when there are hundreds of other sources of calcium? And what are the best sources?
Calcium is one of the essential minerals we cannot live without. It is the main mineral in our bones and it’s also vital for healthy teeth, muscle function, nerve signal transmission, blood clotting and hormonal functions.
Our bones store 99 percent of our calcium – they not only need calcium to be strong, they are also reservoirs of it so when your body needs more calcium, it can be released from the skeleton. Bones are not solid structures that once grown, never change – on the contrary! They are constantly rebuilding, repairing and adapting, so a steady supply of calcium is crucial for them.
How much do we need?
The recommended daily intake varies by country, in the UK it is 700 milligrams, in the US and Australia 1,000 milligrams and slightly more for breastfeeding women and the elderly.
However, in many countries, the average intake is much lower yet people don’t suffer poor bone health. It turns out, having good calcium sources in your diet is important but so are other nutrients, lifestyle habits and the overall effect of your diet on your calcium balance (more on that below).
High intakes of calcium may be dangerous too. If you consume more than 2,000 milligrams a day, there’s a risk some excess calcium may be deposited in soft tissues (e.g. kidneys or blood vessels) and eventually cause problems such as kidney stones. Once intake surpasses 2,000 milligrams per day, the risk of harm increases.
Where do we find it?
Plenty of plant foods are good sources of calcium. The table below lists the best ones.
* Tofu is always a good source of calcium because soya contains it but some tofu has more depending on how it was made. If calcium salts were used in the curdling process, there’s more calcium in the product.
** Plant milks tend to be fortified to match the calcium content of cow’s milk, which is 120 mg.
Spinach, chard and beet greens are fairly rich in calcium but they also contain a substance called oxalate which makes it hard for us to absorb calcium from these foods. It is better to obtain calcium from low-oxalate green vegetables like kale, broccoli, cabbage, watercress and bok choy.
Calcium is also often added to white bread, cereals, drinks, and plant-based products such as yogurt and desserts. There’s no blanket policy on calcium fortification so check the packaging to find out how much is in your chosen products.
We need calcium to grow and maintain healthy bones. As you can see above, there are plenty of plant sources of calcium and we're not dependent on milk to provide this mineral at all. The fact that many people believe otherwise is down to the hugely successful advertising campaigns spanning decades.
The dairy industry distributing promotional leaflets – masqueraded as educational - in schools has also had a heavy impact. Claims such as 'milk is essential for healthy bones' have been banned for years now, simply because they are false, so the dairy industry replaced them with workarounds, such as ‘milk is an excellent source of calcium needed for healthy bones’. Clever, eh?
Luckily, people are becoming more educated about nutrition and the skyrocketing popularity of plant milks is helping to dispel this milk=calcium myth.
Milk and bones
Same applies to excessive amounts of animal protein (from meat, milk, fish and eggs), sugar and processed foods. They may contribute to calcium losses from the bones in older people or those with compromised kidney health – weakening the skeleton and increasing the risk of osteoporosis (Frassetto et al., 2018).
It's due to animal protein containing more sulphur amino acids than plant protein – these form sulphuric acid in the body which needs to be neutralized and it just so happens that calcium is the body’s main acid-neutralizing agent.
If the amount readily available in the blood or muscles is not enough, calcium may be released from the bones. Sugar also produces a lot of acid in the body so may have a negative effect on our calcium balance as well.
Good bone health
When it comes to good bone health, we need a diet containing sufficient calcium, vitamins C, B12, D and K, many other minerals (magnesium, potassium, phosphorus, etc.) and some weight-bearing physical activity.
The latter is important because bones respond to the pressure applied to them – it stimulates them and reinforces the structure. As for all the nutrients, a wholesome vegan diet is perfectly adequate in this respect.
The high content of bone-beneficial nutrients in plant foods has been linked to good bone health of vegetarians and vegans – together with the fact that plant based diets produce much less acid (Knurick et al., 2015; Sahni et al., 2015; Burckhardt, 2016).
However, we do need a couple of supplements. One of them is vitamin B12 and the other is vitamin D. Calcium and vitamin D need each other to work well so if we have plenty of calcium and lack vitamin D, our bones won’t be happy.
Our skin makes vitamin D when exposed to sunlight and 15-20 minutes of exposure are sufficient from April to October. For the rest of the year, it’s not enough. During autumn and winter months, the sun doesn’t shine strongly enough in the northern hemisphere, the days are shorter and we are more covered up. It’s recommended that everyone takes a vitamin D supplement during that time of the year.
If you always use sun-block, spend your days indoors or cover up most of your body at all times, you probably need vitamin D supplements all year long
What we use...
It’s safe to say we’ve come across many different types of multivitamins from various brands. We can personally recommend this multivitamin from wearefeel™, which contains 33 ingredients (including calcium) in their highest quality and bio-availability, with nothing unnecessary added.
Plant protein along with fruit and vegetables – ideally five to 10 servings a day - is important for healthy bones (Dai et al., 2014; Sahni et al., 2015). The best sources of plant protein are beans, lentils, soya (tofu, tempeh, edamame), whole grains (oats, wholemeal bread, whole wheat pasta, quinoa, brown rice), nuts and seeds.
These foods provide a wealth of nutrients crucial for bone maintenance and repair. Most of the plant foods that are rich in protein are also good sources of calcium – it's an ideal food scenario.
A diet including the foods listed above should provide more than sufficient calcium quantities. Supplements are not recommended for the general population as high calcium intakes can be harmful (John Hopkins Medicine, 2016).
However, if you take a multivitamin supplement to cover your vitamin B12 and D needs and it also contains calcium, that’s nothing to worry about as those supplement don’t have very high doses.
Some people worry about phytate reducing the amount of calcium they can absorb from plant foods. Phytate is a natural compound found in whole grains, nuts, seeds and pulses. It binds to iron, calcium, magnesium and zinc, and can reduce their absorption.
However, soaking, cooking, fermenting, leavening (bread), and sprouting all reduce phytate content of foods so there’s no need to worry about it (Gupta et al., 2015). We can certainly absorb enough calcium from plants.
Caffeine and smoking reduce calcium availability to an extent. Whilst the advice on smoking is obvious, when it comes to caffeinated drinks, limiting them to the maximum of four or five a day is sensible.
A varied plant based diet that contains beans, soya, lentils, tofu, hummus, green leafy vegetables, wholemeal bread, nuts and seeds ensures good calcium intake.
If you also add fortified plant milks or other products, you don’t have to worry about calcium in the slightest.