Plant-Based Diets & Calcium



People always ask me where I get my calcium from if I don't eat dairy. 

Yes, cow's milk does contain a fair amount of calcium...but where do cows get their calcium?

Grass! Delicious grass! This reminds of a friend's wedding I attended earlier in the year which was held at a golf course. I was singled-out as the only vegan in the room and told my dinner (lawn clippings) was waiting for me outside on the green. har har har. Very droll. But seriously, where was my dinner?

Now, nothing annoys me more than nutrition experts touting dairy products as the perfect food for:

- weight loss,
building muscle and 
preventing osteoporosis

Why does this annoy me?

Because dairy products aren't human food, and they should certainly not take up an entire food group in our Australian Dietary Guidelines.

Cow/goat/sheep/[insert other mammal here]'s milk is meant for their own offspring, not for human consumption. No other animal on the earth dares to steal the milk of another species, so why should we? 

Dairy milk is a complex cocktail of bioactive substances, designed to facilitate the growth of a newborn calf (around 40kg) to their full-grown adult weight of around 450kg for a dairy cow, not for the routine consumption by adult humans. 

Here's a few convincing reasons to ditch dairy:

1. It's downright cruel

Dairy cows are routinely artificially impregnated in order to keep producing milk (about once annually). The baby calves are separated from their mothers within 12 hours of their birth to reduce the risk of disease, causing intense grief and anguish for the mother and baby calf alike. The cows are known to call out in distress for days following the separation.

These newborn 'bobby calves' (all male calves and 75% of the female calves) are surplus to dairy industry requirements and are slaughtered either for veal or other products (such as leather or pharmaceutical products). In Australia, it is estimated that there are around 700,000 of these calves killed every year. The calves are held in pens until 5 days of age (when they are deemed old enough to slaughter) where they are subject to pathetic welfare standards (such as being fed milk only once daily). They are then transported to abbatoirs where they are distressed, starving, roughly-handled and killed. If you support the dairy industry, you support the death of these innocent baby calves. Most people don't think this happens on Australian farms, but it does

2. It's absolutely filthy

Milk is contaminated with millions of bacteria (many of faecal origin), hence the need to pasteurise it before it is suitable for human consumption. The bacteria remain in the milk, only they are dead. Ick. 

3. It's a major source of saturated fat and cholesterol in the Australian diet

Just 1 cup of full-cream milk contains 6g of saturated fat and 25mg cholesterol. Our dietary requirement for cholesterol is 0mg, as our bodies can produce all the cholesterol we need. The only safe level of cholesterol consumption is zero. How do you avoid cholesterol in foods? Avoid eating animals and their products. Easy. 

4. It's addictive

Casein (one of the main proteins in dairy products) is cleaved by our digestive enzymes to yield a number of opiates (known as casomorphins) with pain-relieving, sedating and addictive properties. This explains why cheese is so difficult to give up: cheese has a higher casein content than milk (as the whey proteins, water and lactose are separated out during the processing of cheese), and hence results in higher levels of these opiates in the blood after consumption. 

5. Dairy consumption stimulates the release of Insulin-like Growth Factor-1 (IGF-1) and insulin (a storage hormone) 

Both IGF-1 and insulin increase the production of androgens (male sex hormones present in both women and men) and stimulate the sebaceous (oil-producing) glands in the skin, which has been linked to the 'epidemic incidence' of adolescent acne in Western milk-consuming societies. Data from the Nurse's Health Study of over 47,000 women found a positive association between milk intake and acne, which is thought to be related to the presence of hormones and other bioactive components of milk. 

6. It's a potent cocktail of sex hormones

So many people are concerned about phytoestrogens (phytoestrogens) in soy products (more on this in another post), but how many people know that cow's milk (particularly skim milk) contains estrogen (among many other sex hormones)? To increased productivity on dairy farms, cows are milked throughout their pregnancies, which results in pregnancy hormones in the milk. Nature has a perfectly good mechanism for preventing offspring from consuming milk laced with pregnancy hormones: lactation is a potent contraceptive. 

7. It's an environmental nightmare

In a country with very limited water supplies, the dairy industry tops the list of water used for agriculture, using a massive 40% of the total water used for irrigation of crops and pastures here in Australia.

Calcium requirements

The Recommended Dietary Intake (RDI) for calcium in Australia is 1,000mg for men and women aged over 19 years, and increases to 1,300mg for men over 70 years and women over 50 years. These requirements are amongst the highest in the world; even in the UK the recommended daily intake is 700mg for men and women. I don't believe there is a magic number of milligrams at which our calcium intake prevents osteoporosis. However, given there is good evidence to suggest our intake of calcium has been much higher in the past (mainly from wild leafy greens), I think it is reasonable to strive to meet the Australian recommendations. 

Plant-based sources of calcium 


-1x 250mL cup of plant milk, fortified with calcium*
-100g firm tofu set with calcium salts (look for the E numbers 509 and 516 on the ingredients list. E511 is a magnesium salt, not a calcium salt. These tofus still contain some calcium (as soy beans are a good source of calcium) but not as much as those set with calcium salts. 


-1 cup bok choy, Chinese cabbage or other Asian green
-100g firm tofu set with magnesium salts ('nigari' or E511 on the ingredients list)


-100mg tempeh 
-1 TB chia seeds
-2 TB blackstrap molasses
-1 TB unhulled tahini (from white or black seeds)
-1 cup cooked amaranth (a gluten-free grain)
-1 cup of cooked kale or 2 cups tightly-packed raw kale


-2 TB of hulled tahini 
-1 cup of broccoli or green cabbage 
-1 cup of cooked chickpeas, kidney beans or lentils 
-1 dried fig
-8 dried apricots
-20g raw almonds 

If we look a little closer at the absorption of calcium from different foods, plant-based sources become even more impressive, as around 60% of the calcium in green vegetables (kale, cabbage, bok choy) is estimated to be absorbed by the body, compared to only around 30% of the calcium from cow's milk.  

So how much kale do we need to eat to get the same amount of calcium as a glass of cow's milk? 

Let's do the maths: 

Cow's milk provides 300mg calcium per 250mL glass at 30% absorption = 90mg calcium absorbed 

Kale provides 100mg per cup at 60% absorption = 60mg calcium absorbed

Hence, just 1.5 cups of kale will result in an equivalent quantity of calcium being absorbed as 1 cup of dairy milk! 

*Check the nutrition information panel to make sure there is 300mg calcium per 250mL serve of plant milk. Most soy milks contain this quantity, but many of the newer plant milks (such as almond) are fortified with much less than this (or not fortified at all). If you are making your own nut milk at home, I usually recommend adding some powdered calcium to ensure 1 cup of the milk contains at least 300mg calcium.