Calcium: Benefits and Sources

From childhood, most of us have probably heard that drinking milk and getting enough calcium in our diet helps keep our bones strong and healthy. But what exactly is calcium, and what foods should we eat to ensure we’re getting enough? Our guide to calcium examines this essential mineral and delves into whether or not dairy really is the best source of calcium for preventing bone loss.

Calcium is the most abundant mineral in our bodies, and it serves many important functions. About 99% of our body’s calcium is stored in our bones and teeth (as calcium hydroxyapatite), providing structure and keeping them strong. In addition to its crucial role in bone health, calcium plays a part in muscle and blood vessel contraction and dilation, blood clotting, nerve transmission, and hormone secretion.1

So how do we get the calcium we need? One way is through eating calcium-rich foods in our diet and taking calcium supplements. Some foods are better sources of absorbable calcium than others, with dairy and leafy greens at the top of the list. Supplements can be helpful if you struggle to get enough calcium in your daily diet; this can be a struggle for those following a vegan diet or those with lactose intolerance that must avoid dairy products. (Also, it’s essential to have adequate vitamin D levels in order to improve calcium absorption in your gut).2 Another way our body gets its calcium is by pulling from existing stores in our bones. This can happen when our blood calcium levels get too low.

Remarkably, our bones are constantly remodeling (breaking down and rebuilding) throughout our lifetimes, with calcium moving in and out during the process. As we age, our bone destruction slowly starts to exceed our bone production.14 This emphasizes the need to consume enough calcium in your youth through a healthy diet — getting adequate amounts of this essential nutrient while your body is rapidly depositing it provides a solid foundation for the future.

For women, especially, the onset of menopause and related decreased estrogen levels triggers increased bone remodeling. This, in turn, requires a greater calcium intake. And while we can’t completely prevent bone loss from happening, consuming enough calcium helps reduce the amount our body has to borrow from our bones.

Osteoporosis

Even if we get the daily recommended calcium we need, we still lose bone mass as we age. In the United States alone, an estimated 10.2 million people over age 50 have osteoporosis.3 Osteoporosis (which means “porous bone”) occurs when your bones break down faster than they are built.4 This puts you at greater risk for bone fractures. And while this condition usually doesn’t cause symptoms or pain, it can creep up on you with a sudden, painful break.

Your sex and age are the greatest risk factors for osteoporosis.15 Women experience rapid bone loss for the first ten years after menopause; in fact, women account for 80% of all osteoporosis cases.16 Your family history, ethnicity (Caucasian and Asian women are the most prone), bone structure, and weight can also play a part in your likelihood of developing bone loss.15 Some medical conditions and medications, such as steroids, can damage your bones when taken long-term and may lead to osteoporosis. Physicians use a bone mineral density (BMD) test to examine your bone health and whether or not you may have osteoporosis or its precursor, osteopenia.5

How to prevent bone loss

The amount of calcium your body needs daily depends on your age and sex. The Food and Nutrition Board of the Institute of Medicine has determined the following Recommended Daily Allowances of calcium. Entries marked with an asterisk are “Adequate Intakes” which are used when there currently isn’t enough evidence to calculate a Recommended Daily Allowance.1

The best way to consume calcium is through your diet. When shopping for calcium-rich foods, take note of nutrition labels. A food with 10% or more of your daily value for calcium is a great source. Since you can only absorb so much calcium at a time, it’s a good idea to space out your calcium-rich foods, if possible. Also, while dairy gets the most attention, there are other food groups that boast strong calcium content. Those on a dairy-free diet can also benefit from fortified foods on the market. We’ve listed below some easy, healthy sources of calcium to get you started.13

The USDA also has an extensive list of foods and their calcium content available to assist you in your meal planning.

What if you’re lactose intolerant?

While dairy is a fantastic source of calcium, it’s not for everyone. The products that contain the most calcium (such as milk) also tend to contain a lot of lactose — a naturally occurring sugar found in milk and milk products.22 Lactose intolerance is a common problem that can lead to uncomfortable symptoms like bloating, gas, and diarrhea.

Luckily, some options are available for those that would like to consume dairy products but have an issue with lactose. You can purchase a lactase enzyme supplement (such as Lactaid) and take it with your food to help break down the lactose you consume or choose dairy products that already contain lactase in them. These products are readily available at most grocery stores.