An estimated 2 million Canadians or 1 in 4 women and 1 in 8 men over the age of 50 have osteoporosis. Osteoporosis refers to bone loss that causes "thinning" or weakening of the bones. Because bone loss occurs without symptoms, osteoporosis often goes unrecognized for many years until one or several fractures (broken bones) occur. Since bones are made primarily of calcium, eating calcium-rich foods helps keep bones strong. At the same time, it helps the heart, blood, and muscles work properly.
Other factors also affect bone strength, such as genetics, weight, amount of weight-bearing exercise, and exposure to sunlight. Sunlight is necessary because it affects the level of vitamin D in the body, which helps the body absorb calcium.
Since the body can't make calcium, we have to get it from the food we eat.
Getting the most calcium from your food
The amount of calcium you absorb from the foods you eat depends not only on how much calcium is in the food, but on how easily it's absorbed, the amount of calcium already stored in your body, and what you eat with the calcium-rich food.
Many researchers say that the best bet for getting calcium is to eat dairy products like milk, yogurt, and cheese because they are high in calcium, and the type of calcium they contain is easily absorbed by the body.
Foods which contain oxalates or phytates, however, interfere with the body's ability to absorb calcium.
High-oxylate foods
- Fruits:
- blackberries
- blueberries
- citrus peel
- Concord grapes
- Damson plums
- gooseberries
- raspberries
- red currants
- rhubarb
- strawberries
- Vegetables:
- amaranth
- beet leaves
- cassava
- collards
- leeks
- okra
- parsley
- purslane
- spinach
- sweet potatoes
- Swiss chard
- Beverages:
- beer
- berry juices
- coffee
- cola
- Ovaltine®
- tea
- Other foods:
- almonds
- chocolate
- cocoa
- peanuts
- peanut butter
- pecans
- poppy seeds
High-phytate foods
- barley
- beans
- bran and wheat cereals
- corn chips
- nuts
- oats
- rice
- rye bread
- sesame seeds
- soybean meal
- wheat bran
- wheat germ
For example, ½ cup of cooked spinach has 122 mg of calcium, but the amount of calcium that the body is actually able to absorb is close to zero because spinach is high in oxalates. If you rely on vegetables as your source of calcium, you should choose low-oxalate vegetables more often, such as kale, broccoli, bok choy, mustard and turnip greens.
How much calcium do you need?
Unfortunately, North American men and women aren't getting enough calcium.
In order to keep your bones healthy, get enough calcium every day and choose low-oxalate, low-phytate fruits and vegetables.
Recommended calcium
| Age and sex (years) | Intake per day |
|---|---|
| Children 1 to 3 years old | 700 mg |
| Children 4 to 8 years old | 1,000 mg |
| Children and teenagers 9 to 18 years old | 1,300 mg |
| Women 19 to 50 years old and men 19 to 70 years old | 1,000 mg |
| Women over 50 years old and men over 70 years old | 1,200 mg |
During pregnancy and while breast-feeding, the recommended calcium intake is:
| Age (years) | Intake per day |
|---|---|
| under 18 | 1,300 mg |
| 18 and over | 1,000 mg |
The US National Academy of Sciences Institute of Medicine can provide more info on recommended intakes.
Calcium rich foods
The following chart lists the amount of calcium found in many common foods.
*add 100 mg for each portion of calcium-enriched milk or yogurt
Written and reviewed by the MediResource Clinical Team