Calcium and Your Bones

Calcium–Rich Foods and Supplements for Strong Bones

Calcium is a key nutrient for your body to stay strong and healthy. It is an essential building block for lifelong bone health in both men and women, among many other important functions. 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: The key to strong bones and lifelong bone health

How much calcium do you need?
Source: Institute of Medicine
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

Calcium can seem confusing. How much should you get? Where should you get it? And what’s the deal with vitamin D, magnesium, and vitamin K? But once you understand the basics, it’s not that hard to include it in your diet and get the calcium you need.
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, and regulate the heart’s rhythm, among other things.

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 particularly important when you’re under the age of 30 and still building 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.

Food is the best source of calcium

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.

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 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.

Avoid high-protein diets: Too much protein draws calcium from the bones

The body needs protein to build healthy bones. But as your body digests protein, it releases acids into the bloodstream that the body neutralizes by drawing calcium from the bones. Following a high-protein diet for a short time is unlikely to make much of a difference. But over a long period of time, eating a lot of protein could weaken your bones.

Magnesium, vitamin D and vitamin K: Calcium’s necessary counterparts

When it comes to your bones, 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. 

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.

Other tips for building strong bones and preventing bone loss

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.

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 and vitamin pills: What you need to know

While food is the best source of calcium, supplements are another option. But it 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.
• 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.