Getting enough calcium on a plant-based diet can initially seem like a bit of a challenge if you don't know what to look out for. In reality however, with just a bit of knowledge and planning it's easy to meet daily calcium requirements even after you've ditched the dairy.
Almost everyone knows calcium is important for strong bones and teeth, but it is also essential for neuromuscular and cardiac (heart) functioning. The skeleton is the storehouse for calcium in the body and the size of these stores are effected by the amount of calcium you eat (and absorb) as well as losses of calcium through the bowels, kidney and skin (in faeces, urine and sweat - calcium is one of the body's electrolytes).
Having a low intake of calcium has been associated with the development of Osteoporosis. When you develop Osteoporosis your bones become weak and porous instead of being thick and dense. As your bones thin you have a higher chance of breaking them, especially if you fall. The prevalence of Osteoporosis in Australia among those aged 50 and over is approximately 23% of women and 6% of men. While calcium is really important for preventing Osteoporosis, other factors like exercise, Vitamin D and protein also play a role. You have the opportunity to build your bones until you're about 30 years old - after that you'll be stuck with what you've got! So it becomes all about maintenance, baby.
Calcium requirements change with age, but the recommended dietary intake of calcium for the average male and female aged 19-50 years is 1000 mg/day. Men continue to need only 1000mg/day until the age of 70. Calcium absorption decreases as we age and unfortunately for females, calcium balance deteriorates at menopause. Therefore it is recommended that females 51 years and over and males 70 years and over consume 1300 mg/day.
Plant-Based Sources of Calcium
There are plenty of good calcium sources to select from on a plant-based diet including low oxalate leafy greens, broccoli, tahini, almonds, fortified plant milks, legumes and calcium set tofu. Check the table below for more info.
Absorbability of Calcium
As the saying goes - its not what you eat, its what you absorb. Other vegetables like spinach, beet leaves and rhubarb also contain high amounts of calcium, however the absorbability is quite low due to their oxalic acid content. You'll see in the table below, low oxalate greens are truly great as far as calcium absorption is concerned - even trumping dairy products.
Perhaps the motto here should be to take a leaf (get it?! 🙄) out of the cows' book and get your calcium straight from the green stuff!
Many plant-based peeps find it's easiest to meet their calcium needs by including a glass or two of calcium fortified plant milk per day - but be careful, in Australia not all plant milks are fortified. The table below is by no means exhaustive, there are so many plant-based milks these days - be sure to check the label of your milk of choice! If the plant milk you drink doesn't have added calcium and you're saddened by the thought of swapping to something else, it's not necessarily the end of the world - as long as you're extra mindful to include other sources of calcium throughout the day.
Other Factors to Consider for Increased Calcium Absorption and Strong Bones
Vitamin D plays two key roles in the development and maintenance of healthy bones – it assists calcium absorption from food in the intestine and it also ensures correct renewal and mineralisation of bone. Our main source of vitamin D is from the sun, very few foods contain vitamin D.
- Mushrooms exposed to UV light (you can buy them ready to roll or do this yourself by placing your plain old button mushies in the sun for an hour)
- Fortified products.
Low protein intake is detrimental both for the building of peak bone mass during youth, and for the preservation of bone mass with ageing. Protein under-nutrition can lead to reduced muscle mass and strength in older adults which increases risk of falls (and therefore fractures).
Important to note however is a relatively high protein intake from animal sources can potentially increase your risk of hip fracture. There have been several studies linking an increased risk of hip fracture or forearm fracture in those women whose diets contained a high ratio of animal protein to plant protein.
Go Easy on Caffeine
Too much caffeine can decrease the amount of calcium your body stores. Limit caffeine to 400 mg a day. That's the amount found in about four regular-sized cups of coffee or eight cups of tea. Remember that colas and energy drinks also contain a lot of caffeine.
Drink Alcohol Sensibly
Drinking too much alcohol on a regular basis can raise your chance of developing osteoporosis. Ideally we should have no more than 2 drinks a day with a couple of alcohol free days during the week.
Watch Out for High Sodium Foods
Eating too much sodium can reduce your bone density. Read food labels and try to keep your sodium intake to less than 2300 mg a day.
It’s important to read labels as many foods have ‘hidden salt’ – meaning the foods don’t necessarily taste salty.