Of all the nutrients that vegans must think about, calcium probably demands the most effort. Sure, other nutrients require attention too, but most are quite easy to obtain. For instance, your needs for Vitamins D and B12 are easily covered by popping supplements every two or three days. As for protein, a variety of vegan foods are loaded with it, plus you can always turn to vegan protein powder should you fall short. Omega 3 needs can be met with a daily tablespoon of ground chia, plus a capsule or two of vegan DHA/EPA.
Meeting your calcium needs requires greater attention. That’s because many foods contain virtually no calcium, and most people don’t supplement for this nutrient. Supplementing is therefore frequently a wise choice, both for vegans and non-vegans.
Dairy Industry Duplicity
Sometimes people on both sides of an argument get their main points spectacularly wrong. That’s especially true in the calcium dispute that rages dairy interests and vegans. The dairy people seem at times deliberately misleading, whereas the vegans also trot out their share of bogus claims.
Using the classic “get ’em while they’re young” strategy, the dairy industry has put calcium needs for growing children and adolescents at the very center of their marketing. By using the “calcium, calcium, calcium” mantra, and holding up milk as a uniquely good source of this nutrient, they’ve created the impression that dairy products are by far the best source of calcium. But, as we’ll discover when we review the calcium content of various vegan foods, that claim just isn’t true.
On top of this, the dairy marketing boards never seem to volunteer the fact that the vast majority of people have problems digesting milk. About 65 percent of the world’s adults are lactose intolerant. And that figure is much higher among people of African and Asian descent—around 99 percent of adults of Chinese descent are lactose intolerant.
Calcium for Vegans: Setting the Record Straight
Unfortunately, vegan advocates are scarcely better than dairy lobbyists when it comes to accurately discussing calcium. A number of vegan books and websites assert that dairy is, in reality, a poor source of calcium. The claim is that the substantial amount of protein found in dairy products inhibits calcium absorption. Often, this argument is accompanied by charts showing the rates of hip fracture in various countries, making it appear that dairy consumption increases rates of hip fracture.
This entire line of thinking has, however, been thoroughly debunked. It turns out that high protein intake doesn’t probably doesn’t have much impact on bone health. In fact, protein has also been shown to improve calcium absorption. As for the hip fracture argument, there are confounding factors that make pointing to this statistic dishonest. For example, hip fracture rates are highest in high-latitude locations with lots of ice on streets and sidewalks—and ice is of course closely associated with falls. On top of that, these high latitude areas tend to mean people have lower vitamin D status, which results in diminished bone health.
As we’re about to see, it’s nonsense to assert that dairy plays an irreplaceable role in ensuring adequate calcium consumption. But the position some vegans take regarding calcium is equally problematic. The reality is that it’s quite possible for a daily milk drinker to see her calcium status decline by going vegan. This is especially likely if she doesn’t make the effort to add calcium-rich vegan foods to replace the dairy products she has stopped consuming.
How Do Vegans Get Calcium?
As with every other nutrient, there’s no hard and fast intake number that applies to everyone. Absorption rates differ from person to person. Setting the target level for any nutrient is an inexact science, but an informed guess is obviously more helpful than no guess at all. So when governments and nutritional councils set targets they try to err on the high side. Their intention is to ensure that the guideline will meet the needs of upwards of 95 percent of the population.
Optimum calcium consumption varies at different ages, being highest during teen years and old age. The Institute of Medicine in the United States sets recommendations for calcium at 1300 mg. for people age nine to eighteen, 1000 mg for adults, and 1200 mg. for women over fifty and men over seventy. These numbers are probably not exactly right, but they’re the best estimate we’ve got. It’s therefore wise to plan your diet so that you can hit these recommendations.
Vegan Calcium Sources
Now that we know that you need something like 1000 to 1300 milligrams of calcium each day, reaching this number involves simple arithmetic. Here is what various calcium-rich vegan foods deliver:
- Tofu (½ Cup or 4.5 ounces. Must have calcium sulfate listed in the ingredients): 430 mg (90 Calories)
- Soy Milk (1 Cup, calcium-fortified, unsweetened): 300 mg. (79 Calories)
- Collard greens (1 Cup, cooked): 268 mg. (63 Calories)
- Mustard greens (1 Cup, cooked): 165 mg. (36 Calories)
- Bok-Choy (1 Cup, cooked) 158 mg. (20 Calories)
- Kale (1 Cup, chopped, cooked): 94 mg. (36 Calories)
- Black Beans (1 Cup, canned) 84 mg. (218 Calories)
- Tahini (1 Tablespoon, roasted): 64 mg. (89 Calories)
- Broccoli (1 Cup, chopped, cooked): 31 mg. (27 Calories)
For comparison, whole milk supplies 276 mg. calcium per cup, and contains 149 calories. So you can see that cow’s milk is an excellent source of calcium, but fortified soy milk is too. And on a per-calorie basis, bok-choy contains more than four times the calcium as whole cow’s milk.
Meeting Your Calcium Needs as a Vegan
The calcium figures above are useful to keep in mind, but they’re also a lot to have to remember. With many calcium-rich vegan foods, the limiting factor of how much you’d want to eat in a day isn’t related to calorie content, but instead to how bulky these foods are.
For instance, kale contains a great deal of calcium per calorie. The trouble is that this calcium is accompanied by a whole lot of bulk. If you tried to meet your daily calcium needs solely through cooked kale, you’d have to eat ten cups a day. You’d have to be deranged to attempt that! Even worse would be the prospect of trying to meet your needs through black beans alone. Just imagine what eating more than ten cups of beans every day would do to you.
Tofu and Soy Milk Can Contain Loads of Calcium
There’s no question that you could get sufficient calcium by eating some combination of beans, greens, and broccoli. But your diet would be on the strange side, and would be bulkier than many people prefer. That’s why the addition of some calcium-fortified soy milk or some calcium-set tofu can make all the difference (Always make sure that your tofu lists calcium sulfate in its ingredients, otherwise it’s not a good source of calcium.)
Together, tofu and vegan milks can transform the task of getting sufficient calcium from tricky to easy. For example, just by drinking a cup of soy milk with breakfast, and then including a half-cup of tofu as part of your lunch, you’ve already met half your daily calcium needs. From there, you need only eat a relatively small amount of beans and greens to put yourself over the top.
Some people object that eating calcium-set tofu and fortified soy milk isn’t “natural,” but this is a baseless concern. Such calcium is as well-absorbed and high quality as the calcium from any other source.
Every sort of leafy green contains a substantial amount of calcium. But there’s an important caveat to keep in mind: several popular greens contain substantial amounts of oxalates (oxalic acid). This substance interferes with calcium absorption. Oxalates won’t cancel out all the calcium your greens contain, but they can prevent you from absorbing most of it.
So if you’re eating greens in order to boost your calcium intake, you should avoid spinach, chard, and rhubarb—all of which are rich in oxalates. Note also that boiling oxalate-rich greens causes some of the oxalic acid to leach out into the water. This significantly improves calcium absorption, assuming you discard the cooking water and don’t use it as soup stock.
The greens mentioned in the previous section—collard greens, mustard greens, bok-choy, and kale—are all low in oxalates, and are therefore superb sources of calcium.
Vegan Calcium Supplements
Some people have trouble getting sufficient calcium through food alone. In these cases, supplements offer an easy way to close the gap. Depending on the brand (check the label), just one tablet can give you a whopping 500 to 1000 mg. of this nutrient, enabling you to easily elevate your intake from inadequate to excellent. Deva Nutrition manufactures an affordable vegan supplement that contains a big dose of both calcium and magnesium.
But don’t just start gobbling supplements without paying heed to your total calcium intake. Too much calcium can easily lead to kidney stones (which are dangerous and excruciating to pass). So make sure that your combined calcium intake from food and supplements doesn’t exceed 1300 milligrams per day.
Bone Health for Vegans
Articles about bone health tend to focus on calcium consumption, but there are two more important factors to consider: vitamin D and exercise.
Bones contain specialized cells called osteoblasts and osteoclasts, which work together to maintain bone strength and prevent brittleness. Just like you need a steady flow of oxygen entering your bloodstream, the same is true of the minerals that enter and leave your bones. Every day, a tiny portion of your skeleton is broken down by osteoclasts. As this is accomplished, osteoblasts then take calcium from your blood and assemble it into a fresh new bone matrix. Increasing the number and function of your osteoblasts strengthens your bones and makes them less prone to breakage.
As you can see, calcium intake is only part of the story where bone health is concerned. So be sure you’re taking in adequate vitamin D. This nutrient is essential for proper osteoclast formation, a vital component in bone health.
The Importance of Exercise
Regular weight-bearing exercise also strengthens bones by improving the performance of osteoblasts and osteoclasts. Weight lifting of any kind obviously qualifies as weight-bearing exercise. That’s true whether you’re doing 200 kilogram bench presses or toying around with 1 kilogram dumbbells.
Not into weights? Cheap portable resistance bands deliver the same bone health benefits as weight training. There are numerous other types of weight bearing exercise. These include: walking, hiking, jogging, climbing stairs, tennis, and dancing.
The two most popular exercises that are not considered weight-bearing are swimming and bicycling. While these can work wonders in terms of aerobic conditioning, they are unlikely to improve bone health.
If the connection between exercise and bone health interests you, check out our Guide to Vegan Fitness. You’ll discover that how easy it is to get more physically active, and unlock substantial benefits.
Three Crucial Takeaways
If you don’t drink cow’s milk and you never give calcium a thought, you’re likely to suffer poor bone health later in life. But you can easily reduce these risks, since it’s easy for vegans to boost bone health. The three core recommendations are:
- Get your 1000 to 1300 milligrams of calcium each day. If you can’t get all of this through food, then take a supplement but be sure not to surpass 1300 milligrams total (food plus supplement) calcium consumption per day.
- Spend a half hour or more each day doing some type of weight-bearing exercise.
- Make sure you’re getting adequate vitamin D. For most vegans, especially those in temperate climates, that means taking a vitamin D supplement.
Vegans and omnivores alike often pay insufficient attention to calcium intake, a fact reflected by the millions of bone fractures occurring due to osteoporosis each year. Fortunately, a well-planned vegan diet coupled with adequate exercise can ensure excellent calcium status today, and good bone health later in life.
For further reading: “Protecting Bone Health on a Vegan Diet,” by Virginia Messina, MPH, RD.