Bone supports our entire weight—but what exactly is it? In essence, it’s a matrix of minerals the body constantly breaks down and rebuilds at a microscopic level. However, if breakdown consistently exceeds build-up, bones lose density. Here's the best bone-building advice.
What You Need This mineral is the single most important component in building and maintaining your bone density. Women aged 19 to 50 require 1,000mg a day, and those over 50 need 1,300mg a day, according to National Health and Medical Research Council (NHMRC) guidelines.
Where to get it Dairy products—especially skim milk and low-fat milk and yoghurt—are excellent sources; these products account for approximately 60% of Australians’ calcium intake. (If you’re lactose intolerant, lactose-free products provide calcium, too.) Other great sources include tinned sardines and salmon, calcium-fortified breakfast cereals, cheese and tofu (if it’s prepared with calcium sulfate).
Supplementary sources Your body can only handle about 500 to 600mg of calcium in one six- to eight-hour period, and it absorbs only about 30% of that. One easy way to remedy the shortfall?
If you consume one or two cups of milk or yoghurt daily, you’ll come closer to meeting your recommended daily intake (RDI) if you also take a daily supplement that provides 500mg of calcium citrate or 600mg of calcium carbonate, advises Dr Ethel Siris, director of the osteoporosis clinic at Columbia University Medical Center in New York. (It’s fine if your dose is included in your daily multivitamin.) For best absorption, take calcium carbonate with meals; you can take calcium citrate at any time of day.
Can you take too much? Although it’s an uncommon problem, consuming excess calcium can cause kidney stones, and one major study has linked elevated levels of this mineral to a slightly heightened risk of heart attack. It’s unconnected, however, with the ‘calcifications’ that may show up on mammograms. For adults, the NHMRC sets the safe daily upper limit of calcium at 2,500mg.
What you need D is essential for proper calcium absorption; people up to the age of 50 need 5mcg daily. If you’re 50 to 70, that figure jumps to 10mcg. Over 70? You need 15mcg.
Where to get it You can’t reap the full benefits of calcium without vitamin D, which can be found in some of the same sources, like dairy products. (A 250ml glass of vitamin-D-fortified Anlene milk provides half of your RDI.) You’ll also find it in fatty fish, such as salmon and mackerel; egg yolks; and D-fortified breakfast cereals.
The sun is another key source of D, as sunlight-exposed skin synthesises the vitamin; however, if you use sunscreen, have very dark skin or spend a lot of time indoors, your body’s capacity to manufacture it may be limited. Live in an area that has low UV levels? (Think Tasmania.) You’re also more at risk of experiencing D deficiency during winter.
Supplementary sources If you’re concerned about getting insufficient vitamin D, ask your doctor to do a blood test. If necessary, he or she will prescribe appropriate supplements.Can you take too much? In a word, yes. For adults, the NHMRC recommends a vitamin-D intake of no more than 80mcg per day.
What you need Protein is another vital part of the healthy-bone equation. A woman who weighs around 70 kilos needs up to 77g per day, according to a 2010 study published in Aging Health. Although the RDI for a woman of this weight is 53g, research suggests that another 24g per day can improve bone strength. Protein also boosts IGF-1—a growth factor that’s important for bone formation.
Where to get it Poultry, lean meats, fish, beans, tofu and dairy products all pack protein. To give you a sense of how much: 85g of cooked beef contain around 27g of protein, 100g of tinned sardines have 17g, a cup of lentils gives you 13.5g, and a 200g tub of fat-free yoghurt provides 13g.MORE: Osteoporosis