Your body is similar to a well-built structure where calcium is the essential foundation. Calcium is the most abundant mineral in the body. It is essential for many bodily functions, including building strong bones and teeth, muscle contraction, nerve signal transmission, cardiac function, and more (Yu, 2022).
Calcium plays a critical role in preventing conditions like osteopenia and osteoporosis. Osteopenia is characterized by low bone mineral density (BMD). Osteoporosis marks more significant bone loss with a corresponding increased risk of fractures (Wright, 2014).
In this article, we'll discuss the relationship between calcium and osteoporosis. You'll learn how calcium contributes to bone health, how much calcium you need, food sources of calcium, and when taking calcium supplements may be a good idea.
What does calcium do?
Your bones are constantly remodeling, where old bone breaks down and new bone forms. Calcium is vital in this process, as it's the primary mineral that makes up our bones, providing strength and structure (Yu, 2022).
Nearly all the calcium in your body is stored in the bones. Since bone health is only one of calcium's jobs, the body will pull calcium from the bones for other functions if you don't get enough from your diet (IOM, 2011).
Throughout childhood and the teenage years, your body builds more bone than it breaks down, increasing bone mass. This bone-building process typically continues until approximately age 30, when you reach peak bone mass (Lu, 2016).
After age 30, the bone remodeling process begins to favor bone breakdown over formation, especially as women reach menopause and estrogen levels decline (Song, 2017).
As low calcium intake can exacerbate this process, supporting bone health relies on optimizing calcium intake and ensuring you include nutrients needed for calcium absorption, like vitamin D.
Calcium and vitamin D
Both low calcium and low vitamin D are risk factors for developing osteoporosis. Calcium is the primary building material for our bones, while vitamin D is the assistant that guides calcium to ensure it gets to the right place (Weaver, 2016).
Vitamin D helps with calcium absorption by increasing the efficiency of the digestive tract in absorbing calcium from your diet. It also reduces calcium loss through the kidneys, conserving calcium levels within the body. Finally, vitamin D helps maintain stable blood calcium levels by effectively utilizing calcium for bone-building and other vital functions. (Fleet, 2017).
How much calcium do you need?
Adult women aged 19 to 50 need 1,000 mg of calcium daily. The recommended amount increases to 1,200 mg daily for women over 50 as postmenopausal women absorb less calcium than premenopausal women (Emmanuelle, 2021).
Calcium absorption also depends on diet, alcohol intake, vitamin D levels, and how much you take in at each meal. When you eat smaller amounts of calcium, the body can efficiently absorb more of the ingested calcium. However, if a meal contains high amounts of calcium, absorption efficiency decreases, resulting in a lower percentage of calcium absorbed (Fairweather-Tait, 2002). This also means that if you already have enough calcium in your diet, calcium supplements aren’t necessarily going to improve bone health.
How to meet your calcium needs
The best way to ensure you get enough calcium to support strong bones is through your diet. Dairy is a primary source for many people because it's so well absorbed and contains a lot of calcium per serving. For example, one glass of low-fat milk contains around 300 mg of calcium (Shkembi, 2022).
Certain vegetables also contain calcium, although the amount of calcium per serving is lower than dairy. Compounds naturally found in plant foods—like oxalates and phytates—can also lower absorption from vegetables. Spinach, for example, contains 30 mg of calcium in one cup, but absorption is much less (Shkembi, 2022).
Which foods are the best sources of calcium?
A well-balanced diet that includes a variety of calcium-containing foods can help you meet your recommended needs.
Here are 12 calcium-rich foods for bone health:
- Calcium fortified non-dairy beverages like soy or almond milk
- Bok choy
- Garbanzo beans
Should you take calcium supplements?
Supplements may be indicated in certain situations when dietary intake is low. People who avoid dairy products due to food allergies, intolerances, or diet patterns such as vegan diets are at risk of not getting enough from their diet (Bakaloudi, 2021). Research also suggests that many people consume less than the recommended amounts of calcium, even when they don't have dietary restrictions.
You can find calcium in multivitamins with mineral products, in combination with other nutrients like vitamin D, or as a single nutrient. Calcium supplements, especially when combined with vitamin D, may increase bone mineral density and reduce the risk of fractures, especially at the hip (Chung, 2009, Yao, 2019). Still, it's likely most beneficial for people not getting enough calcium in their diet (Reid, 2014).
If you aren't sure whether or not you get enough calcium from food, a doctor or registered dietitian can help you determine if taking a supplement is a safe and helpful option.
The bottom line on calcium for bone health
Understanding the importance of calcium and its role in bone health is vital for maintaining strong and healthy bones throughout your life. It can be particularly important for people who have been diagnosed with osteoporosis or those who are at high risk of developing osteoporosis. Calcium is crucial for building and maintaining bone density and supporting other essential bodily functions such as muscle contractions and nerve transmissions.
It's also important to remember that calcium doesn’t work alone to optimize bone health. Nutrients such as vitamin D play a significant role in enhancing calcium absorption. Exercise and a healthy lifestyle also contribute to overall bone strength and well-being.
It's never too late to support your bone health. Small diet and exercise changes can make a significant difference for a stronger, more resilient you.