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Calcium and Bone Health

Eating to Protect Your Bones and Prevent Osteoporosis

Calcium and Your Bones In This Article

Calcium is a key nutrient for your body to stay strong and healthy. Almost every cell in the body uses calcium in some way, including the nervous system, muscles, and heart. It is also an essential building block for lifelong bone health in both men and women. While the amount you need depends on various factors, everyone can benefit from eating calcium-rich foods, limiting foods that deplete calcium, and getting enough magnesium and vitamins D and K-nutrients that help calcium do its job.

Calcium for overall health and strong bones

Calcium is the most abundant mineral in the body, one that plays many vital roles. Your body uses it to build healthy bones and teeth, keep them strong as you age, send messages through the nervous system, help your blood clot, your muscles contract, and regulate the heart’s rhythm, among other things.

If you don’t get enough calcium in your diet, your body will take calcium from your bones to ensure normal cell function, which can lead to weakened bones or osteoporosis. Calcium deficiency can also lead to mood problems such as irritability, anxiety, depression, and difficulty sleeping. 

Despite these vital functions, many of us are confused about calcium and how to best protect our bones and overall health. How much calcium should you get? Where should you get it? And what’s the deal with vitamin D, magnesium, vitamin K and other nutrients that help calcium do its job?

This confusion means that many of us are not getting the recommended daily amount of calcium. Approximately one in two women (and about one in four men) over the age of 50 will break a bone due to osteoporosis. But osteoporosis is not an inevitable part of getting older. Whatever your age, it’s important to take care of your bones and get the calcium you need.

How your body gets calcium

Your body gets the calcium it needs in one of two ways. The first and best way is through the foods you eat or the supplements you take. However, if you’re not consuming enough calcium, your body will get it in a different way, pulling it from your bones where it’s stored. That’s why diet is key.

Getting enough calcium in your diet is not just important for older people. It’s vital for children, teens, and young adults under the age of 30 to get enough calcium to build bone mass. Making smart choices now will help you avoid serious bone loss later in life. But no matter your age, you can take steps to protect your bones and put the brakes on osteoporosis.

The calcium and osteoporosis connection

Osteoporosis is a “silent” disease characterized by loss of bone mass. Due to weakened bones, fractures become commonplace, which leads to serious health risks such as the inability to walk. People with osteoporosis often don’t recover after a fall and it is the second most common cause of death in women, mostly those aged 60 and older. Men are also at risk of developing osteoporosis, but typically 5 to 10 years later than women. Fortunately, osteoporosis is preventable for most people, and getting enough calcium in your diet is the first place to start.

How much calcium do you need?

0-6 months

210 milligrams / day

7-12 months

270 milligrams / day

1-3 years

500 milligrams / day

4-8 years

800 milligrams / day

9-18 years

1,300 milligrams / day

19-50 years

1,000 milligrams / day

50+ years

1,200 milligrams / day

Food is the best source of calcium

Your body is able to absorb more calcium from food than it can from supplements. There are several reasons why your calcium intake should primarily come from the food that you eat rather than from supplements. Firstly, your body is able to absorb more calcium from food than it can from supplements. In fact, studies show that even though people who take calcium supplements have a higher average daily intake, those who get most of their calcium from food have stronger bones.

On top of the better absorption rates, calcium from food often comes with other beneficial nutrients that help calcium do its job.

Furthermore, using high-dose calcium supplements may increase your risk of heart disease. Doctors advise that you get as much of your daily calcium needs from food as possible and use only low-dose supplements to make up any shortfall.

Good food sources of calcium

  • Dairy: Dairy products are rich in calcium in a form that is easily digested and absorbed by the body. Sources include milk, yogurt, and cheese.
  • Vegetables and greens: Many vegetables, especially leafy green ones, are rich sources of calcium. Try turnip greens, mustard greens, collard greens, kale, romaine lettuce, celery, broccoli, fennel, cabbage, summer squash, green beans, Brussels sprouts, asparagus, and crimini mushrooms.
  • Beans: For another rich source of calcium, try black beans, pinto beans, kidney beans, white beans, black-eyed peas, or baked beans.
  • Herbs and spices: For a small but tasty calcium boost, flavor your food with basil, thyme, dill weed, cinnamon, peppermint leaves, garlic, oregano, rosemary, and parsley.
  • Other foods: More good sources of calcium include salmon, tofu, oranges, almonds, sesame seeds, blackstrap molasses, and sea vegetables. And don’t forget about calcium-fortified foods such as cereals and orange juice.
Calcium content in food

Food

Serving

Calcium (mg)

Skim, 1 or 2% milk

1 cup

285-306

Low-fat fruit yogurt

8 oz.

345

Swiss cheese

1 oz.

224

Canned sardines

4 oz.

325

Collards (boiled)

1 cup

358

Figs (medium, dried)

10

269

Orange juice (calcium-fortified)

1 cup

270

Tofu

1/2 cup

258

Soybeans

1 cup

175

Oatmeal (instant)

1 packet

163

White beans

1 cup

161

Canned salmon

3 oz.

181

Firm tofu

¼ block

163

Cooked spinach

1 cup

245

Sources: Bowes and Church's Food Values of Portions Commonly Used & The George Mateljan Foundation for The World's Healthiest Foods

Calcium and milk: The pros and cons

There is some debate in the nutrition world over the benefits of dairy products. Many nutritionists believe that consuming milk and dairy products will help prevent osteoporosis. On the other hand, some believe that eating a lot of dairy will do little to prevent bone loss and fractures and may actually contribute to other health problems.

One thing, however, is certain: milk and other dairy products contain a lot of calcium in a highly absorbable form. Dairy products are a quick and easy way to get calcium in your diet, one you may already be enjoying on a regular basis. But you should also be aware of the potential downsides.

  • Dairy products are often high in saturated fat. A diet high in saturated fat increases the risk of heart disease. To limit your saturated fat intake, choose low-fat or non-fat versions of your favorite dairy foods. Switch out your 2% milk for 1%, and once you adjust to that, try skim milk. You can also find many reduced-fat cheeses, low-fat ice cream and frozen yogurt, and healthy butter substitutes. Some taste better than others, so shop around.
  • Most milk contains high levels of estrogen. Some studies show a possible link between the natural estrogens found in milk and breast, prostate, and testicular cancer, which rely on sex hormones to grow. Part of the problem is modern dairy practices, where the cows are continuously pregnant and milked over 300 days per year. The more pregnant the cow, the higher the hormones in the milk. Despite being labeled “hormone-free” organic milk can still be high in natural hormones. To reduce your exposure, stick to skim milk. Because the hormones are found in the milk fat, skim milk has a much lower level.
  • Many people are lactose intolerant, meaning they are unable to digest lactose, a sugar found in milk and milk products. Symptoms range from mild to severe, and include cramping, bloating, gas, and diarrhea. Beyond the discomfort it causes, lactose intolerance can also interfere with calcium absorption from dairy. Certain groups are much more likely to have lactose intolerance: 90 percent of Asians, 70 percent of blacks and Native Americans, and 50 percent of Hispanics are lactose intolerant, compared to about 15 percent of Caucasians.

If you are lactose intolerant but still want to enjoy dairy:

  • Before eating dairy, take a pill (capsule or chewable tablet) containing enzymes that digest milk sugar.
  • Buy milk that has the lactase enzyme added to it.
  • Experiment to see how you do if you eat small portions of dairy and gradually increase the serving size.
  • Combine dairy with other foods. This may lessen your symptoms.
  • You may be able to tolerate cheese, which has less lactose than milk. Aged cheeses, in particular, have very little lactose (Parmesan, cheddar, Swiss).

The bottom line for getting calcium from dairy products

If you choose to consume dairy, then it’s best to opt for 1% or nonfat milk and other low-fat dairy products, which are lower in saturated fat and natural hormones. Choosing organic products when possible will also decrease your exposure to synthetic hormones and other additives. And if you decide that dairy is not the best choice for you, or you can’t tolerate milk products, there are other ways to include calcium in your diet.

Calcium-rich foods: Tips for upping your calcium intake

When you eat a diet rich in whole foods—vegetables, whole grains, nuts, seeds, and fruits—not only do you get a wonderful variety of tastes on your plate, but you also give your body the different nutrients, including calcium, that it needs. To boost your daily intake, try to include calcium-rich foods in multiple meals or snacks.

Tips for adding more dairy to your diet—even if you don’t like milk

  • Use milk instead of water when making oatmeal or other hot breakfast cereals.
  • Substitute milk for some of the liquid in soups such as tomato, squash, pumpkin, curries, etc.
  • Milk can be added to many sauces or used as the base in sauces such as Alfredo and Béchamel sauce.
  • Make whole-wheat pancakes and waffles using milk or yogurt.
  • Get creative with plain yogurt. Use it to make a dressing or a dip, or try it on potatoes in place of fattier sour cream.
  • Add milk or yogurt to a fruit smoothie. You can even freeze blended smoothies for popsicles.
  • Enjoy a small piece of cheese for dessert or as a snack. Try cheddar, mozzarella, Gouda, jack, Parmesan, or a type of cheese you’ve never had before.

Tips for getting your calcium from non-dairy sources

  • Greens, herbs and spices can easily be added to soups, casseroles, or stir-fries. Greens that are especially good are: kale, collard greens, and parsley. Also good: turnip greens, dandelion greens, mustard greens, beet greens, broccoli, and cabbage. Spice up these and other dishes with garlic, basil, thyme, oregano, and rosemary to add more nutrients.
  • Eat dark green leafy salads with your meals. Try romaine hearts, arugula, butter lettuce, mesclun, watercress, or red leaf lettuce (avoid iceberg lettuce as it has very little nutrient value). You can also add herbs to the salads or the dressings for flavor and nutrients—dill and basil taste especially good in salads.
  • Add extra servings of veggies to your meals, i.e. asparagus, fresh green peas, broccoli, cabbage, okra, bok choy.
  • Top salads or make a sandwich with canned fish or crustaceans with bones, such as sardines, pink salmon, and shrimp.
  • Use beans/legumes as part of your meals. They are wonderful in stews, chili, soup, or as the protein part of a meal. Kinds to try: tofu, tempeh, black-eyed peas, black beans, and other dried beans. You can also snack on edamame.
  • Start your day with oats. Steel cut oats or rolled oats make a wonderfully comforting and filling breakfast. For an added punch include cinnamon
  • Snack on nuts and seeds such as almonds and sesame seeds. You can also add these to your morning oatmeal.
  • Drink tea. Try green tea, which you can substitute for coffee, as well as herbal teas and infusions, such as oatstraw, nettle, and red clover.
  • Order or prepare sandwiches on whole grain wheat bread.

Beyond calcium: Other nutrients for healthy bones

When it comes to healthy bones and preventing osteoporosis, calcium alone is not enough. There are a number of other vital nutrients that help your body absorb and make use of the calcium you consume. The most important of these are magnesium, vitamin D, and vitamin K. Other nutrients such as vitamin C and vitamin B12 may also play an important role in bone development.

Calcium and magnesium

Magnesium helps your body absorb and retain calcium. Magnesium works closely with calcium to build and strengthen bones and prevent osteoporosis. Since your body is not good at storing magnesium, it is vital to make sure you get enough of it in your diet. Magnesium is found in nuts, seeds, whole grains, seafood, legumes, tofu, and many vegetables.

  • Swiss chard and spinach are excellent sources of magnesium. Include spinach in your salads or add chard to soup.
  • Eat more summer squash, turnip and mustard greens, broccoli, sea vegetables, cucumbers, green beans, and celery.
  • Replace refined grains (i.e. white flour and white rice) with whole grains.
  • Add pumpkin, sesame, flax, or sunflower seeds to cereal, salad, soup, and other dishes.
  • Snack on nuts (almonds and cashews are especially high in magnesium).
  • Reduce sugar and alcohol, which increase the excretion of magnesium.

Calcium and vitamin D

Vitamin D is another critical nutrient that helps the body absorb calcium and regulates calcium in the blood. Your body synthesizes vitamin D when exposed to the sun. However, a large percentage of people are vitamin D deficient—even those living in sunny climates.

If you don’t spend at least 15 minutes outside in the sun each day or you live above 40 degrees latitude (north of San Francisco, Denver, Boston, Rome, and Beijing), you may need an extra vitamin D boost. Good food sources of vitamin D include:

  • fortified milk
  • eggs
  • cheese
  • fortified cereal
  • butter
  • margarine
  • cream
  • fish
  • shrimp
  • oysters

You may also want to consider taking a vitamin D supplement. Optimal vitamin D intake is between 1,000 IU and 2,000 IU (international units) per day.

Calcium and vitamin K

Vitamin K helps the body regulate calcium and form strong bones. Include vitamin K in your diet by eating green, leafy vegetables or taking a supplement with vitamin K. You should be able to meet the daily recommendation for vitamin K (120 micrograms for men; 90 micrograms for women) by simply eating one or more servings per day of broccoli, Brussels sprouts, dark green lettuce, collard greens, or kale.

Vitamin C and vitamin B12

Less is known about the role of these vitamins in bone health. However, new research suggests that vitamin C and vitamin B12 may play important roles in bone health and the prevention of osteoporosis.

  • Studies have indicated that consuming foods rich in vitamin C may help to prevent bone loss. Good sources include citrus fruit, such as oranges and grapefruit, strawberries, kiwi, mango, Brussels sprouts, and green bell peppers.
  • Studies have also found a link between vitamin B12 levels and bone density and osteoporosis. Good sources of B12 include seafood such as salmon, haddock, and canned tuna, as well as milk, yogurt, eggs, and cottage cheese.

Other tips for building strong bones and preventing osteoporosis

In addition to adding calcium-rich foods to your diet, there are a few other important things you can do to strengthen your bones and keep them that way.  You can also minimize the amount of calcium you lose by reducing your intake of certain kinds of foods and other substances that deplete your body’s calcium stores.

Eat more alkali, less acid foods

There’s growing evidence that foods that create acids in the body can lead to bone depletion, especially in older adults. Acid doesn’t come from acidic foods as you’d expect, but rather from foods that get broken down into acids. These are primarily cereal grains and protein.

Of course, just about every article on healthy eating will tell you that eating more whole grains is a good thing, as is eating lean protein like fish and low-fat dairy. If this seems confusing, you’re not alone.

The thing to remember about all aspects of healthy eating is that balance is key. In this case, it’s important to eat plenty of alkaline foods—fruits and vegetables—in order to balance out or neutralize the acid from the protein and cereal grains in your diet. To prevent calcium loss (and improve many other aspects of your health), it’s also important to reduce your intake of refined cereal grains from products such as white bread, pizza dough, donuts, muffins, and cookies, and limit your protein intake from red meat. In other words, eat more fruit and veggies and reduce your intake of “bad” proteins and grains, not the good stuff.

For lifelong bone health, exercise is key

When it comes to building and maintaining strong bones, exercise is essential. Studies show that the risk of osteoporosis is lower for people who are active, especially for those who do weight-bearing activities at least three times a week. Exercise also increases your muscle strength and coordination, which helps you avoid falls and other situations that cause fractures.

There are many different ways to include weight-bearing exercises in your life. Some examples are walking, dancing, jogging, weightlifting, stair climbing, racquet sports, and hiking. Find something that you enjoy doing and make it a regular activity.

Minimize calcium-draining substances

There are a number of foods and substances that, when consumed in excess, drain calcium from your bones and deplete your body’s calcium stores.

Caffeine – Drinking more than 2 cups of coffee a day can lead to calcium loss. The amount lost can have a significant impact on older people with already low calcium levels. You can buffer the effects to an extent by drinking coffee with milk.

Animal protein – Protein is a vital part of your diet, but getting too much protein from animal sources can lead to calcium loss. To avoid weakening your bone’s calcium stores, limit yourself to 4 ounces of meat per day.

Alcohol – Alcohol inhibits calcium absorption and disrupts your body’s calcium balance in a number of ways. Try to keep your alcohol consumption to no more than 7 drinks per week.

Salt – Eating too much salt can contribute to calcium loss and bone breakdown. What you can do: taste your food before adding more salt and reduce processed foods, which are often high in sodium.

Soft drinks – It’s best to avoid drinking soft drinks regularly. In order to balance the phosphates in soft drinks, your body draws calcium from your bones, which is then excreted.

Calcium supplements: What you need to know

While food is the best source of calcium, supplements are another option. But it's important not to take too much. There's no evidence that taking more than the Recommended Dietary Allowance (RDA) is beneficial. In fact, recent studies suggest that taking high daily doses of calcium supplements (1,000 mg or more) may damage the heart and have other negative health effects. It also matters what type of calcium you take and how you take it.

  • Calcium citrate is a highly absorbable calcium compound. Calcium citrate can be taken at any time, but absorption is best when taken with a meal.
  • Calcium ascorbate and calcium carbonate are not as easily absorbed as calcium citrate. Absorption is better when taken with food or soon after a meal.

Be smart about calcium supplements        

  • Don’t take more than 500 mg at a time. Your body can only absorb a limited amount of calcium at one time, so it is best to consume calcium in small doses throughout the day.
  • Don't take more than the recommended amount for your age group. Take into account the amount of calcium you get from food. And remember: more isn't better; it may even be harmful to your heart.
  • Take your calcium supplement with food. All supplemental forms of calcium are best absorbed when taken with food. If it’s not possible to take your supplement with food, choose calcium citrate.
  • Purity is important. It’s best to choose calcium supplements with labels that state "purified" or, if you’re in the U.S., have the USP (United States Pharmacopeia) symbol. Avoid supplements made from unrefined oyster shell, bone meal, or dolomite that don't have the USP symbol because they may contain high levels of lead or other toxic metals.
  • Be aware of side effects. Some people do not tolerate calcium supplements as well as others and experience side effects such as acid rebound, gas, and constipation. For acid rebound, switch from calcium carbonate to calcium citrate. For gas or constipation, try increasing your intake of fluids and high-fiber foods.
  • Check for possible drug interactions. Calcium supplements can interfere with other medications and vitamins you’re taking. Talk with your doctor or pharmacist about possible interactions. Any medications that you take on an empty stomach should NOT be taken with calcium.

Calcium and preventing osteoporosis: The bottom line

Try to hit your daily targets for the following foods, nutrients, and activities:

Daily Target What You Need to Know

Calcium

Aged 19-50: 1,000mg

Over 50: 1,200mg

Food is the best source of calcium. Use a supplement only to make up any short fall in your diet.

Vitamin D

Aged 18-70: 600 IU

Over 70: 800 IU

If you live north of San Francisco, Denver, Boston, Rome, or Beijing, you may need an extra vitamin D boost during winter.

Protein

Aged 18-70: 0.4g of protein per lb. of body weight

Over 70: 0.5 to 0.7g per lb. of body weight

This translates to at least 65 grams of protein for a 180lb adult, or 68 to 102g of protein for an older person weighing 150 lbs.

Fruits & Vegetables

At least 5 one-cup servings

The best way to neutralize excess acid.

Excercise (weight-bearing)

30 minutes or more

Choose walking, dancing, jogging, weightlifting, stair climbing, racquet sports, or hiking.

More help for health and nutrition

Resources and references

General information about calcium

Calcium and Milk: What's Best for Your Bones and Health? – Fact-filled article covers what nutritionists know about calcium, osteoporosis, and more. (Harvard School of Public Health)

What You Need to Know About Calcium – Information on good food sources of calcium and the pros and cons of supplements. (Harvard Health Publications)

Nutrition and Bone Health: The Calcium Myth – Information on calcium and the other nutrients, including magnesium and vitamin D, which are vital for bone health. (Better Bones)

Calcium – Learn about the mineral calcium, including sources, why it is important for our body, and what foods contain calcium. (The George Mateljan Foundation)

Calcium supplements

Calcium and Vitamin D: Important at Every Age – Advice on how to choose the right calcium supplement and minimize side effects and interactions. (National Institute of Arthritis and Musculoskeletal and Skin Diseases)

Osteoporosis and bone health

Promoting Lifelong Bone Health – In-depth guide to building strong bones and limiting bone loss, including nutrition tips and important lifestyle factors. (Nutrition MD)

Bone Builders: Exercise – More detailed information on exercises that can help you strengthen your bones. (University of Arizona)

Osteoporosis – Detailed information on osteoporosis, including the causes, nutrient needs, and dietary suggestions. (The George Mateljan Foundation)

Authors: Maya W. Paul, Melinda Smith, M.A., Lawrence Robinson, and Jeanne Segal, Ph.D. Last updated: December 2014.