Are you feeding your bones a healthy diet? If not, the consequences could be serious. According to the National Osteoporosis Foundation (NOF), some 10 million Americans suffer from osteoporosis, which makes bones less dense and more susceptible to fractures. Another 34 million people are at risk for the condition. Osteoporosis will cause about half of all women over 50 to break a bone at some point in their lifetime, the NOF estimates. One-third of those who suffer hip fractures will require nursing-home care, and one-fifth will die in the first year after the fracture.
Bess Dawson-Hughes, MD, director of Tufts HNRCA Bone Metabolism Laboratory, says your first line of defense against osteoporosis is adequate calcium and vitamin D intake. Theres been some confusion about the best strategy for getting enough calcium, however, and many experts have had second thoughts about the rush to calcium supplements.
You should try to get most of your calcium through your diet, using supplements only as needed to fill the gap, Dr. Dawson-Hughes advises. The Recommended Dietary Allowances (RDA) for calcium, daily, for adults are 1,000 milligrams for ages 19-50 and men ages 51-70, and 1,200 milligrams for women age 51-plus and men age 71-plus.
Id avoid exceeding the RDA, she adds. There is no known benefit to exceeding it and there may be increased risk of adverse events, however small.
Despite what you may have heard from makers of calcium supplements, more is not necessarily better as long as youre meeting the RDA. A 2011 study published in BMJ concluded that increases in calcium intake beyond a moderate amount had little benefit in preventing osteoporosis or fractures. On the other hand, several studies have raised concerns about a slightly higher risk of heart attacks among women taking calcium supplements.
VITAMIN DS KEY ROLE: Vitamin D is the other partner in the bone-building one-two punch most crucial to avoiding osteoporosis. Without enough vitamin D, your body cant make use of the calcium you consume-no matter how much calcium-rich foods you eat or supplements you take.
Controversy has also swirled around vitamin D and whether extra vitamin D helps protect your bones. But Dr. Dawson-Hughes says reports doubting the effectiveness of vitamin D in fighting fractures are outliers. The NOF, Institute of Medicine, Endocrine Society and International Osteoporosis Foundation, she notes, have reviewed the evidence and concluded that vitamin D lowers fracture risk. There is some lack of consensus about the dose and blood levels that are optimal, but no disagreement about whether D lowers fracture risk.
How much vitamin D do you need? Reports have concluded that getting 400 International Units (IU) a day is not effective in lowering fracture risk. But there is evidence that higher doses of vitamin D-700-1,000 IU per day-do lower fracture risk, Dr. Dawson-Hughes says.
That might, however, be more vitamin D than most people can get from food sources alone. A glass of fortified milk provides only 100 IU, and most other food sources contain even less. You can also synthesize vitamin D in your skin from sun exposure, but people in northern latitudes and those who stay mostly indoors probably dont get enough year-round sun to keep up with vitamin D demands.
So, unlike calcium, you may need supplements to obtain adequate vitamin D. The RDA for vitamin D is 600 IU daily for men and women ages 51-70 and 800 IU for ages 71-plus, but some experts believe those intakes are too low. Theres no downside to taking a supplement that, combined with normal dietary intake, would put you slightly above those levels: The Tolerable Upper Intake Level for vitamin D, beyond which there might be safety concerns, is 4,000 IU. (The body manages the vitamin D it makes itself, so you dont need to worry about combining sun and supplements.)
EATING NUTRIENT-RICH: Obtaining adequate calcium, vitamin D and other nutrients for your bones is increasingly important with age, as the bodys natural remodeling of bones gets out of balance. Old bone material is always being broken down, with new bone formed to take its place. In older people, particularly women after menopause with lower estrogen levels, the building of new bone can no longer keep up with bone loss. Women are also at greater risk of osteoporosis because they often start out with lower bone mass than men and because they live longer, meaning more time for out-of-balance bone remodeling to do damage.
The ingredients of new bones have to come from your diet. What kind of diet can best help your body maintain strong bones? A study published in 2011 in the American Journal of Clinical Nutrition compared fracture risk and dietary patterns among more than 5,000 people over age 50. Those consuming an energy-dense diet-high in calories from meat, desserts, fries, snacks and soft drinks-were at greater risk of suffering a fracture. A nutrient-rich dietary pattern-with more whole grains, fruits and vegetables-was associated with an 18% lower risk of fracture in women over 70. Men following a nutrient-rich pattern were at 17% lower risk, and women overall reduced their risk by 14% by picking foods rich in nutrients, not calories.
Protein is also important, though its not a vitamin or mineral, adds Dr. Dawson-Hughes. Your body requires protein for bone formation; like vitamin D, protein is also important for the strength of the muscles surrounding your bones. Many Americans far exceed the RDA for protein of 46 grams per day for adult women and 56 grams for men. Vegetarians (especially vegans) and older people, who often consume fewer calories and thus less protein, may not be getting enough, however. (See our September 2012 Special Supplement for more on protein.)
NECESSARY NUTRIENTS: The other elements of a bone-healthy diet include most of the nutrients you already know you need-but may not be getting enough of. Among the most important are:
Magnesium – Among other things, magnesium appears to affect how the body uses calcium and the hormones that regulate calcium. With age, the bodys ability to absorb magnesium from food tends to decrease, while loss of magnesium through the kidneys may increase. Older people are also more likely to take medications that can interfere with magnesium absorption, such as diuretics and proton-pump inhibitors.
The RDA for magnesium for men over age 30 is 420 milligrams daily and for women over 30 is 320 milligrams. According to the National Institutes of Health, dietary surveys of Americans consistently show that intakes of magnesium are lower than recommended amounts. Another analysis found that more Americans fall short in getting adequate magnesium than any other mineral. (See our September 2012 Special Report for more on magnesium.)
Potassium – This mineral-because it is bound to alkaline compounds such as bicarbonate-helps your body maintain a balance between acidity and alkalinity. The typical American diet is rich in protein, cereal grains and other acid-residue foods. (Foods effect on the bodys acid-alkaline balance depends on the residues they produce, rather than the acidity of the food itself.) Too much acidity can increase your bodys excretion of calcium, leaving less available for your bones. Potassiums role in countering this acidity may be why several studies have shown a significant positive association between dietary potassium intake and bone mineral density.
Yet according to national nutrition surveys, fewer than 2% of US adults meet the RDA of 4,700 milligrams of potassium daily. (See our March 2012 Special Report to learn more about potassium.)
Phosphorus – It should be no surprise that phosphorus is important to healthy bones, since bone mineral actually consists of calcium and phosphorus. Most US adults get adequate phosphorus from their diet, but 10% to 15% of older women have intakes of less than 70% of the RDA, which is 700 milligrams daily for adults. Some health conditions such as diabetes, malnutrition and alcoholism can cause low levels of phosphorus, as can those that make it difficult to absorb nutrients, such as Crohns and celiac disease.
The high intake of phosphorus in the US population due to phosphate-containing soft drinks has actually led to concerns over too much phosphorus in the diet. Excess intake might disrupt the bodys mineral metabolism and bone-related hormones. If youre eating an overall healthy diet and dont suffer any condition known to lead to low levels of phosphorus, theres no reason to seek to consume extra, in food or supplements.
Vitamin K – Some animal and human studies have demonstrated that vitamin K can not only increase bone mineral density in osteoporosis patients but also actually reduce fracture rates. Other studies have shown that vitamins D and K work together to boost bone density, and that vitamin K positively affects calcium balance.
Most people are already getting the recommended 120 micrograms daily for men and 90 micrograms for women of vitamin K. If you eat a healthy diet with plenty of leafy green vegetables, you should have no worries about vitamin K. (People on anticoagulant medications need to be aware of interactions with vitamin K and follow their doctors advice about consuming foods high in vitamin K.)