Calcium and bone health

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1 Calcium and bone health Calcium is a mineral that is essential for healthy bones and teeth, as well as for regulating many important functions in the body, such as heart muscle function and nerve transmission. About 99% of the calcium in the body is stored in the skeleton (bones and teeth). There are three different phases of bone mass development through life: Age Phase Birth to Rapid bone growth - maximum development of bone mass years years Plateau phase 30 years onwards Bone loss phase - acceleration of bone mass, especially in women after menopause When our diets don t contain enough calcium, the body starts using the calcium stored in bones. Over time, this causes the bones to weaken and they become thin, brittle and can fracture easily. A low dairy intake can result in reduced bone mass during the growth phase and low bone mass is associated with increased fracture risk in children and in adults. This often goes unnoticed for many years and can result in a condition called osteoporosis. In South-Africa, one in three women over the age of 50 is affected by osteoporosis, and the incidence is said to be increasing. Oestrogen has a protective effect on bone and when oestrogen levels decrease women lose more calcium. Calcium needs therefore increase after menopause and hormone replacement therapy is encouraged to prevent unnecessary bone loss. Calcium needs also increase during pregnancy and breastfeeding. It is therefore especially important for girls to get adequate calcium before puberty and during adolescence to ensure that their bones reach peak mass and to protect them from developing osteoporosis.

2 Are you getting enough calcium? The adequate daily intake for calcium varies depending on age and stage of the lifecycle: Age group Children 1-3 years Children 4 8 years Children 8-18 years Adult females and males years Adult females and males 50 years onwards Pregnant and breastfeeding years Adequate Daily Intakes for calcium (mg) Food sources of calcium Dairy foods, such as milk, yoghurt and cheese contain significant quantities of calcium and the calcium in dairy is well absorbed. Non-dairy sources of calcium include: dark green, leafy vegetables (e.g. broccoli, kale, collards, turnip greens, mustard greens); the soft, small bones of sardines and canned salmon; clams; oysters; soy beans; fortified orange juice; almonds and tofu (made by calcium precipitation). The approximate calcium content of various foods: Food Quantity Calcium mg Cheese parmesan 30g 460 (matchbox) Fresh goats milk 1 cup (250ml) 330 Yoghurt low-fat 1 tub (175ml) 320 Cows milk fat free (skim) 1 cup 310 Cows milk - low-fat (2%) 1 cup 305 Cheese goat 30g 300 Cows milk full-cream 1 cup 295 Cheese medium fat 30g 280 Cheese hard (cheddar etc) 30g 240 Yoghurt fat-free, unsweetened 1 tub 230 Salmon, canned with bones 100g 213 Processed cheese, full-cream 30g 200 Cheese mozzarella 30g 170 Cheese feta 30g 160 Cheese ricotta 30g 90

3 Cottage cheese, low-fat 30g (1 Tbs) 20 Soya milk - unfortified 1 cup 10 Calcium is best absorbed in an acid environment, such as when the stomach secretes acid during a meal. Therefore taking a calcium supplement with a meal improves its absorption. Lactose (milk sugar) and Vitamin D stimulate the absorption of calcium. Calcium absorption is decreased by foods that contain oxalic acid (oxalate), e.g. spinach, chard, rhubarb and beet greens. Foods that contain phytic acid (phytate), which is mainly found in outer husks of cereal grains combines with calcium to form calcium phytate, and this decreases calcium absorption. Dietary fibre may decrease calcium absorption, but only when very large quantities are consumed (more than 30g per day). Certain medications can make calcium less available or increase loss of calcium from the body. As we get older, we lose more calcium because we secrete less acid in the stomach and our skin produces less vitamin D. Diets that are very high in animal protein (e.g. meat, chicken and fish), caffeinated coffee or sodium (found in salt and many processed foods) may result in higher calcium losses from the body. Fitting more calcium into your diet Add a few tablespoons of yoghurt to the milk in your breakfast cereal Add milk to scrambled eggs and omelets Use milk instead of water when baking biscuits, scones and muffins Add milk to boiled potatoes before mashing for a creamier texture Try mozzarella cheese on low fat savoury biscuits as a snack Add almonds and sesame seeds to stir-fries, salads, rice or couscous With this combination of foods you would have an intake of well over 1000mg: Milk, low-fat 500ml (2 cups) 600mg Cheese 30g (size of a 200mg matchbox) Salmon/sardines/pilchards half a can 200mg Bread 4 slices 80mg Broccoli ½ cup 70mg Almonds 25g 60mg TOTAL 1210mg

4 Calcium supplements may be recommended for people who cannot include enough calcium-containing foods in their diets. There are various types of calcium supplements available, such as calcium carbonate and calcium citrate. Supplements differ in their physical and chemical properties and should be selected after considering a person s medications, medical conditions and age. Because calcium is best absorbed in an acid environment, it should be taken with food to benefit from the stomach acid that is released during a meal. Menu planning

5 Breakfast A small cup of cooked oats porridge made with milk or ½ a cup of high fibre bran or whole-wheat Pronutro PLUS a cup of milk or yoghurt PLUS a small piece of fresh fruit. Add 1-2 Tbs of flaked almonds to the cereal for extra crunch and calcium. 1 slice of rye bread or seed loaf PLUS one poached or boiled egg PLUS a small yoghurt 1-2 sardine fillets with sliced tomato on toast PLUS a small piece of fruit. Light meal 1-2 slices of rye bread or seed loaf with ½ a tin of salmon / grated cheese / peanut butter / baked beans in tomato sauce PLUS salad vegetables with avocado or olives and a small piece of fruit. A bowl of thick bean or lentil vegetable soup PLUS 1 slice of rye bread / seed loaf PLUS a piece of fruit. Add some grated mozzarella cheese to the soup. Main meal Snack A small sweet potato or a small cup of cooked brown rice or pasta PLUS skinless chicken / lean beef / mince / fish or fish cakes made with pilchards or sardines / beans PLUS vegetables with grated cheese or salad with avocado or olives and feta cheese PLUS a small piece of fruit with some fat-free yoghurt. A small tub of fat free fruit yoghurt 3 Provitas with 30g cheese A glass of milk plain or add 2 tsp. Nesquik / Milo A handful of almonds