Calcium is best known for its role in promoting bone health and reducing the risk of osteoporosis, but it is also important for many other aspects of health. Calcium works synergistically with other minerals and nutrients, so even if you take supplements, it’s a good idea to obtain some calcium from whole foods as well.
Foods with a very high calcium content include milk, yogurt (especially plain), cheeses (especially Swiss), and canned sardines and salmon (with bones). Fatty fish such as salmon, sardines, mackerel, and tuna are also good sources of vitamin D, which is required for proper absorption of calcium. Additional good sources of calcium include broccoli, turnip greens, kale, okra, Brussels sprouts, Chinese cabbage, dandelion greens, collard greens, and mustard greens.
Although milk has a high calcium content, it’s not always an ideal calcium source because many people are lactose-intolerant. Research also suggests that calcium absorption is lower with milk than from certain vegetables such as broccoli, Brussels sprouts, and leafy greens.
There are some foods that are very nutritious and high in calcium but contain oxalates, which block the absorption of calcium. These foods include spinach, beet greens, rhubarb, wheat bran, and beans. They’re still worth eating because they promote health in other ways, but they shouldn’t be considered calcium sources even though they contain calcium. Wheat bran, in particular, interferes not only with absorption of its own calcium content but also that of other foods eaten at the same time, so avoid consuming it with calcium-rich foods (the small amounts found in most wheat breads should not be a problem – only products with a very high bran content such as bran cereals are likely to have a significant impact on calcium absorption). Drinking a lot of coffee (three or more cups per day) can also reduce calcium absorption.
If taking calcium supplements, be sure to take vitamin D as well to promote proper absorption.
- Association of Women for the Advancement of Research and Education, “Osteoporosis: Foods, Herbs and Supplements for Bone Health,” ProjectAWARE, 2001.
- Graci, S.; DeMarco, C., Dr.; & Rao, L., Dr., The Bone-Building Solution, John Wiley & Sons Canada, 2006.
- Health Canada – Food and Nutrition, “Dietary Sources of Calcium,” 2002.