J. Edward Puzas, PhD, is a professor of orthopedics and the senior associate dean for basic research at the University of Rochester Medical Center, in New York.
Q: Why should I care about bone thinning?
A: More than half of Americans over the age of 50 develop osteoporosis, and its four times more common in women than men. Once your bones become thinner and more fragile, youre more apt to suffer fractures. If youre elderly, this can be fatal. A 65-year-old woman who breaks her hip has a 1 in 7 chance of dying as a result.
Q: Im in my 20s. Shouldnt I wait to worry about my bone health when I hit menopause?
A: Lifestyle factors at any age can affect the health of your bones. The body maintains careful blood levels of calcium throughout your life span. If levels get too low, the body will “borrow” calcium from your bones to replenish other parts of your body. And because too-low calcium levels are life-threatening, your body will go so far as to use up all of your bones in order to get more.
So if, over the course of your lifetime, your calcium intake is a little bit lower than what you need, your body will keep depleting your bone reserve, eventually leading to osteoporosis.
Its like a bank account. You need to put back in what you take out. That means that getting enough calcium on a daily basis is critical.
Q: How much calcium do I need?
A: Kids need about 1,500 milligrams of calcium a day until they hit puberty. Adults ages 15 to 50 are fine with about 1,000 milligrams a day, but older people, especially postmenopausal women, need to go back up to 1,500 milligrams daily.
Which foods are good sources of calcium?
A: All dairy products are excellent sources of calcium, as are deep-green, leafy vegetables such as spinach and collard greens, and sardines (calcium is found in the fish bones). Nowadays, you can also find calcium in fortified orange juice and bread.
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Q: Do I get less calcium from low-fat or skim dairy products?
A: No, theyre all equally bioavailable. If youre worried about consuming too much fat, go for skim or 2% milk or reduced-fat cheese.
Q: Do I have to buy calcium supplements?
A: You dont have to, but most people dont get all the calcium they need from dietary sources. The National Institute of Arthritis and Musculoskeletal and Skin Diseases has a calcium calculator so you can check to see if youre getting enough calcium from food sources.
If youre not getting what you need from meals, think about taking a supplement.
Q: Is it better to get calcium from supplements or from food?
A: Theyre both equal, but get as much calcium and other nutrients from food as you can. A balanced diet is better for overall health.
Q: Do certain people need more calcium than others?
A: Yes. For instance, people with a malabsorption syndrome, such as celiac disease, need more of the mineral. Celiac disease is an inflammatory condition that makes it difficult to fully absorb calcium and other nutrients.
Q: Do I need vitamin D too?
A: People with a vitamin D deficiency (and thats a lot of people these days) dont efficiently transport calcium across the intestine, so they dont absorb as much calcium from their diet as they should.
Calcium absorption is so important; its probably the main reason why we all need to be getting an adequate intake of vitamin D.
Q: How much vitamin D do I need?
A: The National Institutes of Health recommends 200 international units (IUs) of vitamin D a day for women ages 19 to 50, 400 IU for women ages 51 to 70, and 15 IUs for women 71 and older. You can get vitamin D from sun exposure (15 minutes a day without sunscreen), fortified milk or other types of food, and supplements.
Q: Can I get it wrong when it comes to supplements? Is it possible I could take too much calcium?
A: You probably cant get too much calcium unless youre prone to kidney stones. In healthy people, excess calcium passes through the body and is peed out without any trouble.
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Q: I walk for a workout. Is that helping my bones?
A: Walking is about the best exercise you can do to stave off osteoporosis, as walking involves mechanical loading, which stimulates the formation of bone. If you remove the mechanical loading element, the bones think they dont need to be there and actually get thinner, like what happens with astronauts in space.
All athletes have higher bone densities than non-athletes, but runners, tennis players, basketball players, and others engaging in weight-bearing activities have higher densities than those doing non-impact sports such as swimming.
To prevent osteoporosis, a good brisk walk is about as good as you can do. Running is even better if you dont have any problems with your joints.
Q: Are there any medications I might be taking that can increase my risk of osteoporosis?
A: Steroids used to treat allergies or asthma or to prevent tissue or organ rejection (but not those used by bodybuilders) can increase your risk of bone thinning. The bone thinning cant always be counterbalanced by adding more calcium.
Its always a good idea to talk about it with your doctor if youre on medication or about to go on medication.
Q: Are there any medications that prevent osteoporosis?
A: Several drugs used to treat osteoporosis can also help prevent it, including Evista (raloxifene), the hormone Calcimar, and the class of drugs known as bisphosphonates (such as Fosamax and Boniva).