Bone is living tissue, constantly renewing itself. Although bone is strong and relatively flexible, everyday wear and tear causes tiny structural defects, much like those that occur in the foundations of a building over time. In our bodies, there are two groups of special cells that perform the work of a “maintenance crew.” Osteoclasts excavate any areas of damaged or weakened bone and then osteoblasts fill in the crevices with material that hardens to form new bone. This two-part process is called bone remodelling, and the cycle of remodelling is completed every three to four months in a healthy young adult.
As we age, the two groups of cells that form the maintenance crew become less efficient in working together – the osteoclasts remove old bone faster than the osteoblasts are able to rebuild it. In addition, calcium, like many nutrients, is absorbed less effectively as we age. In people who have relatively healthy bones, adequate calcium intake can help the remodelling process stay balanced. Studies of older adults show that adequate calcium intake can slow bone loss and lower the risk of fracture.
For those over 50, Canada’s Food Guide recommends 3 servings of milk and alternatives (2 servings for adults under age 50) – yogurt, cheese, calcium-fortified beverages, puddings, custards, etc. This essentially means that, if you are over 50, you need the equivalent of one good serving of dairy at each meal.
Take your pick: have a glass of milk (go ahead and have chocolate milk if you prefer), have soup that’s made with milk (like cream of mushroom soup), main courses made with cheese such as lasagna, or have yogurt with fruit for dessert. A 3 cm cube of hard cheese has as much calcium as a cup of milk. Skim milk products provide as much calcium as whole milk with the added advantage of less fat and cholesterol. Dairy products are an excellent source of calcium and are also a good source of protein.
If you are intolerant to dairy products or if you prefer to avoid dairy, there are other alternatives food sources that are high in calcium.
- calcium-fortified soy, almond and rice beverages (check the nutrition labels)
- calcium-fortified orange juice (check the nutrition labels)
- canned salmon or canned sardines. (When you eat the bones that have been softened by the canning process, these foods are excellent sources of calcium.)
HOW MUCH CALCIUM DO WE NEED?
|Age||Daily Calcium Requirement (this includes your diet and supplements)|
|19 to 50||1000 mg|
|pregnant or lactating women 18+||1000 mg|
|CALCIUM CONTENT OF SOME COMMON FOODS||PORTION||CALCIUM*|
|Food Product – 250 to 300+ mg Ca|
|Buttermilk||1 cup/250mL||186 mg|
|Fortified orange juice||1 cup/250mL||300 mg|
|Fortified almond, rice or soy beverage||1 cup/250mL||300 mg**|
|Milk – whole, 2%, 1%, skim, chocolate||1 cup/250mL||300 mg***|
|Milk, evaporated||1/2 cup/125 mL||367 mg|
|Milk – powder, dry||1/3 cup/75 mL||270 mg|
|Yogurt – plain, 1-2% M.F.||3/4 cup/175 mL||332 mg|
|Food Product – 160 to 249 mg Ca|
|Almonds, dry roast||1/2 cup/125 mL||186 mg|
|Beans – white, canned||1 cup/250 mL||191 mg|
|Cheese – Blue, Brick, Cheddar, Edam, Gouda, Gruyere, Swiss||1 ¼”/3 cm cube||245 mg|