Excellent sources of well absorbed calcium include fortified plant milks, calcium-set tofu and cruciferous vegetables such as bok choy, collard greens, rapini, turnip greens and kale (pictured).Getty Images/iStockphoto
Milk, yogurt and cheese are synonymous with calcium.
We’ve been told for years that dairy products are excellent sources of bone-building calcium. Many people, though, don’t include dairy in their diets, for a range of reasons including lactose intolerance, milk allergies, plant-based eating and animal welfare concerns.
The good news is it’s entirely possible to get the calcium you need from other foods.
Here’s a guide to calcium’s health benefits, your daily requirement and how to get what you need from plants and other non-dairy foods.
What calcium does
About 99 per cent of calcium in the body is stored in bones, giving them structure and strength. The remaining calcium is found in blood, muscle and other tissues.
If you don’t consume enough calcium, the body moves the mineral from bones into the bloodstream to maintain a steady level.
That’s because calcium is essential for muscle function, blood vessel contraction and dilation, normal heart rhythm, blood clotting, nerve transmission and hormone secretion. Consuming adequate amounts is critical for building strong bones when we’re young and limiting bone loss when we’re older, helping to protect against osteoporosis. Higher dietary intakes have also been linked to lower risk of premenstrual syndrome and colorectal cancer.
How much calcium?
Health Canada’s recommended daily intakes for calcium are based on the amount needed to maintain strong, healthy bones.
Children at the ages of 1 to 3 require 700 mg of calcium each day, while children between the ages of 4 and 9 need 1,000 mg. Pre-teens and teens need more calcium to support bone growth, with 1,300 mg recommended each day.
The daily calcium requirement for all adults between the ages of 19 and 50, and for men up to the age of 71, is 1,000 mg. Women over 50 and men 71 and older need 1,200 mg per day.
Getting calcium from non-dairy sources
The following dairy-free foods supply generous amounts of calcium. Consider adding them to your regular diet. For comparison, one cup of milk or ¾ cup of yogurt provide roughly 300 mg of calcium.
Bok choy, rapini, kale
When it comes to green vegetables, these three offer highly bioavailable calcium, the kind your body can absorb and use.
Once cooked, one cup of bok choy, rapini or kale supplies 158 mg, 200 mg or 177 mg of calcium, respectively.
Broccoli also contains well-absorbed calcium, but a smaller amount, at 62 mg per one cooked cup.
Spinach contains the most calcium of all leafy greens, but only 5 per cent of it is absorbed thanks to its high oxalate content. Oxalates and phytates, natural compounds in plants, can bind to calcium, decreasing its absorption.
Collard greens, Swiss chard and beet greens are also high in oxalates.
You’ll get more calcium from your greens if you eat them cooked rather than raw. Cooking increases bioavailable calcium by breaking down oxalates.
Calcium-set tofu
Tofu is made by coagulating soy milk and pressing the curds into blocks. When calcium sulphate or calcium chloride are used to coagulate soy milk, calcium-set tofu can be an excellent source of the mineral. You’ll find calcium sulphate or calcium chloride on the ingredient list.
Extra firm and firm tofu made with calcium sulphate typically provide 150 to 200 mg of calcium per 170 g. That’s equivalent to one-third of a package for extra firm tofu, or one-half of a package for firm tofu.
Brands made with calcium-containing coagulants can vary in calcium content, so be sure to read labels.
Canned fish (with bones)
An 85 g serving of canned sockeye salmon with bones provides 200 to 270 mg of calcium, depending on the brand. It also serves up 640 to 740 IU of vitamin D, a nutrient that helps increase calcium absorption in the gut.
The same portion of canned pink salmon provides 115 to 230 mg of calcium and 500 to 550 IU of vitamin D. If you avoid canned salmon because of the soft bones, mash them with a fork when breaking up the salmon.
Sardines also deliver plenty of calcium, with 324 mg per 85 g.
Fortified milk alternatives
Made from nuts, seeds, soybeans, chickpeas, yellow peas, oats or rice, fortified plant-based “milks” are an excellent source of calcium, delivering 300 to 500 mg per one cup serving.
Choose a product labelled “unsweetened” to avoid added sugar. “Original” versions contain 4 to 7 g of sugar (one to two teaspoons worth) per serving.
Tahini, almond butter
If your go-to spread is peanut butter, consider changing it up. Two tablespoons of tahini, made from calcium-rich roasted sesame seeds, has 128 mg of calcium.
The same serving size of almond butter supplies 110 mg. Peanut butter, while nutritious, contains only 14 mg of calcium per two tablespoons.
If you think your usual diet is low in calcium, speak to your dietitian or health care provider about a calcium supplement that’s right for you.
Leslie Beck, a Toronto-based private practice dietitian, is director of food and nutrition at Medcan. Follow her on X @LeslieBeckRD
Leslie Beck