By Jasmin Lim
The subject of calcium and where you get it from is a hotly debated one. I recall my mum’s childhood horror stories of the milkman delivering milk to her school in the early hours of the morning, exactly half a pint for each pupil. It was the days before fridges and chillers, and that milk delivered in the morning sat glistening in the sun all the way until morning tea – the result? A rather unpleasant bottle of lukewarm milk.
Despite this, she braved her nauseated tummy and gulped down every last drop. Why? To give her strong and healthy bones of course!
To this day milk has been hailed as the hero of all calcium sources, while the concept of obtaining enough calcium from a whole-food, plant based diet (no dairy products to be seen) has largely been ridiculed. So now, lets tackle this topic.
First off, how much calcium do we really need?
The current daily recommended intake for calcium is around 1,200 milligrams. However, many plant-based experts believe these requirements are based on a diet high in animal protein consumption, and as you may not have known, animal protein has a high excretion rate of calcium, thereby forcing you to consume more calcium to make up for the inherent calcium excretion. However, when following a whole-food, plant-based diet, calcium excretion is much lower, which logically means that a plant-based eater’s calcium intake can also be much lower, being as low as 500-750 milligrams a day.
But doesn’t calcium come from dairy?
Ironically, calcium doesn’t magically come from cows frolicking in fields. Like iron and magnesium, calcium is a mineral found in soil. These minerals are absorbed into the roots of plants, and so cows don’t produce calcium themselves, but obtain it from the calcium rich plant foods they eat – making the real source of calcium richness the earth. So now you may be thinking, “so wouldn’t a well balanced plant-based diet have plenty of calcium?” – and yup, you are absolutely, positively, 100% right.
What is bioavailability, and why is it important?
The amount of calcium we ingest may be less important than how much we actually absorb. 1 cup of milk may contain about 300mg of calcium, but did you know that only about 30% of this is actually absorbed, representing its bioavailability to our bodies. So how does milk compare to some common plant-based alternatives?
- The calcium in firm tofu has about the same absorption rate as milk, hovering around 31%. But while ½ a cup of tofu may yield the same amount of calcium as 1 cup of milk, it contains more protein, far less saturated fat and about a tenth of the sodium – and so calcium aside, which would you pick?
- The calcium in dark leafy greens has a much better absorption rate than dairy products, hovering around 50-60%. 1 cup of bok choy, 1½ cups of kale or 2 cups of broccoli contain the same amount of calcium as a glass of milk – not to mention a plethora of antioxidants, vitamins and other essential minerals.
Still not convinced? A recent study comparing the bone mineral density of long-term vegans versus omnivores found that although vegans had vastly lower dietary calcium and protein intakes, they enjoyed the exact same bone density as their meat-eating counterparts – once and for all debunking the myth that we need dairy for strong bones.
In conclusion, while the choice is yours to consume dairy or not, don’t make that choice because you think you need to consume dairy products to obtain enough calcium from your diet. You can get all the calcium you need from a well balanced whole-food, plant based diet. So why not switch it up and try something new in your routine, perhaps skip that morning glass of pasteurized and homogenized milk (which is hardly a wholefood anymore) and have an antioxidant, vitamin, enzyme and mineral rich green smoothie instead? – Now there’s some food for thought.
Find Megan’s tips and tricks for creating the perfect green smoothie here.
Heaney, R. (1993). Protein intake and the calcium economy. Journal of the American Dietetic Association, 1259-1260.
Ho-Pham, L., Nguyen, P., Le, T., Doan, T., Tran, N., Le, T., & Nguyen, T. (2009). Veganism, bone mineral density, and body composition: A study in Buddhist nuns. Osteoporosis International, 2087-2093.
Oliveira, Rosane. Everything you ever needed to know about calcium.
Hunt, Curtis, Johnson, LuAnn K. (2007). Calcium requirements: new estimations for men and women by cross-sectional statistical analyses of calcium balance data from metabolic studies. American Society for Clinical Nutrition.
Walsh, S. (2002). Diet and Bone Health.