Calcium helps to build and maintain healthy bones. It is also involved in blood clotting and nerve and muscle function. The body has good systems to keep the levels of calcium in the blood very stable. A diet low in calcium will result in calcium being taken out of the bones to keep the calcium levels up. Over many years bones can become porous and lose strength, resulting in osteoporosis.
Calcium is deposited into bones in childhood and the teen years, and maximum bone density is achieved in the early 20s. Calcium is then slowly lost out of the bones, especially in women after the menopause. A good calcium intake protects the bones at all ages.
Milk and milk products are the best source of calcium in the diet. One serve (300mg) of calcium is found in:
Adults need 2 1/2 to 4 servings per day!
It is sometimes suggested that broccoli, wholegrains or other foods can provide calcium if you do not like milk or soy milk products. However, the amount needed is very large and generally unpractical. For example the following foods provide as much calcium as 1 cup of milk:
If you are intolerant to milk and soy milk and are using an alternative milk, check that it is supplemented with calcium. Rice milk, almond milk, oat milk, quinoa and chia milk may have zero calcium. They also may have little protein and are not a good substitute for cow or soy milk.
Some people need a calcium supplement. Look for 1000-1200mg of calcium. You may benefit from a supplement that also contains Vitamin D.
Vitamin D helps the body absorb calcium and low Vitamin D levels in the blood can increase the risk of developing osteoporosis. The body produces vitamin D naturally when skin is exposed to sunlight during everyday activities. Exposure of hands and face for 10 minutes a day or 1 hour per week is usually enough, but some people will still have low levels even when they spend a lot of time outside. Ask your GP to check your Vitamin D levels. It is important to balance any sun exposure with the risk of skin cancer.
Bone strength also depends on weight-bearing exercise. Bones are like muscles; making them work stimulates their development. Weight-bearing exercise should be a priority on most days of the week, including activities like walking, jogging, tennis, golf, dancing and lawn bowls. Even if you have osteoporosis, there are many benefits of being active. As well as preventing bone loss, you can improve balance, flexibility and co-ordination, which are all important in avoiding falls.