Calcium is vital for building and maintaining strong, healthy bones.Most adults need 1,000 mg to 1,200 mg of calcium per day.Prioritize calcium-rich foods first, and consult a health care provider before taking supplements.
Calcium is an essential mineral for bone health, giving your skeleton the strength and structure it needs to support you every day. Because bones are living tissue that constantly break down and rebuild, getting enough calcium is essential for keeping them resilient over time.
“Over 99% of the body’s calcium is stored in the bones and teeth, and it serves as a building block for bone remodeling,” says Umo Callins, M.S., RD, CSSD, CPT. Without enough calcium in your diet, the body draws from its bone reserves to support critical functions like muscle movement and nerve signaling, which can gradually weaken bones.,
In this article, we’ll explore what happens to your bones when you get enough calcium, how much you need, the best food sources and when supplements may—or may not—be helpful.
Why We Love Calcium for Bone Health
Calcium is essential for strong, resilient bones that can handle the physical demands of daily life. As a key component of bone tissue, it helps bones support movement, absorb impact and adapt to activity throughout life. Getting enough calcium is particularly important in early adulthood, when the body is still building and reinforcing its skeletal foundation.
“Your bones are constantly remodeling, which means they are repeatedly breaking down old bone and rebuilding new,” says Callins. Adequate calcium helps support this process, giving bones the resources they need to withstand everyday wear and the changes that come with aging.
Research suggests that getting enough calcium in young adulthood may have lasting benefits. Studies show that both sufficient dietary calcium intake—and, when necessary, supplementation—between ages 20 and 35, when peak bone mass is still developing, can improve bone density and help reduce bone loss later in life. Building a stronger skeletal reserve early on can provide long-term protection as natural bone breakdown accelerates with age.
Calcium continues to support bone health later in life, particularly during periods of accelerated bone loss, such as after menopause. As estrogen levels decline, bone breakdown can outpace bone formation. Calcium, often paired with vitamin D, may help slow declines in bone mineral density. That said, research in older adults is mixed, especially when it comes to calcium supplements. While some studies show modest improvements in bone density with calcium or calcium-plus–vitamin D supplements, others find little effect, particularly with fracture prevention.,
Fortunately, calcium from food sources like dairy products may help maintain or increase bone mineral density in adults over 50, especially when paired with other bone-supporting strategies like strength training.
Calcium Deficiency
About 38% of adults in the United States don’t get enough calcium from their diet. When calcium intake is inadequate, the body draws the mineral from bones, gradually weakening them over time.
“Calcium deficiency doesn’t always show obvious symptoms early on, and unless someone takes certain tests, like bone density scans or blood tests, you might not even know you have a problem,” says Bonnie Taub-Dix, RDN. “This is particularly dangerous later on in life when you might see more bone loss, fractures, muscle cramps or weakness.”
Taub-Dix adds that meeting calcium requirements throughout the lifespan is essential, as inadequate intake during childhood and adolescence can also affect peak bone development.
How Much You Need
Calcium needs vary, but can generally are based on life stage and sex:
Adults ages 19–50: 1,000 milligrams per dayMen ages 51–70: 1,000 mg per dayWomen ages 51+: 1,200 mg per dayMen ages 71+): 1,200 mg per day
Needs may be higher for people with osteoporosis, increased fracture risk or conditions that affect calcium absorption. While calcium is essential, more isn’t always better—the upper limit from food and supplements combined is generally 2,000 to 2,500 mg per day, depending on age.
Getting enough vitamin D is also important, since it helps the body absorb calcium. For most people, focusing on calcium-rich foods and using supplements only when needed is the safest way to meet daily requirements.
Food Sources of Calcium
“I always start with a food-first approach when possible because foods provide calcium alongside other bone-supportive nutrients like protein, vitamin D and magnesium,” says Taub-Dix. Both experts emphasize choosing a mix of dairy and nondairy options that are easy to incorporate into meals and snacks.
Top food sources of calcium include:
Milk, yogurt and cottage cheese (including lactose-free options)Fortified plant milks, such as oat, soy or almond milkCalcium-set tofu (tofu made with calcium sulfate)Canned salmon or sardines with bonesLeafy greens like kale, bok choy and collard greensChickpeas and almondsFortified cereals or juices
Spreading calcium-rich foods throughout the day can improve absorption and help meet daily needs consistently.
Is Calcium Safe for Everyone?
Calcium from food is safe for most people, but supplements aren’t necessary—or appropriate—for everyone. Certain medical conditions and medications can affect how the body handles supplemental calcium, so some individuals need to exercise caution.
“Calcium supplements can be helpful, but they’re not one-size-fits-all,” says Callins. People with a history of kidney stones or conditions that affect calcium metabolism may need to be especially careful. Supplements can also interfere with the absorption of certain medications if not timed properly.
For most people, Dix recommends prioritizing calcium-rich foods and using supplements only when needed. As always, it’s a good idea to consult a health care provider before starting any new supplements to ensure they’re safe and appropriate for you.
What to Look For in a Calcium Supplement
If you decide a calcium supplement is right for you, choosing one thoughtfully can help maximize benefits while minimizing risks. Here’s what dietitians want you to know when deciding:
Prioritize Bioavailability. Not all forms of calcium are absorbed equally. “Calcium citrate is often better tolerated and absorbed, especially for people with low stomach acid or digestive issues, while calcium carbonate is often more affordable and effective when taken with food,” says Dix.Look for Independent Verification. Choose supplements that are independently tested by organizations such as USP or NSF. Independent verification helps ensure the product contains what the label claims, is free from harmful contaminants and meets quality and safety standards.Consider Your Personal Needs. Consider how much calcium you’re already getting from food and if a supplement may be beneficial. To help you decide this, work closely with your registered dietitian or other health care provider.Read Labels Carefully. If you have food allergies or sensitivities, check labels for potential cross-contamination and added ingredients.
Our Expert Take
Calcium plays a vital role in keeping bones strong and resilient throughout life, especially when intake is consistent and paired with other healthy habits. Prioritizing calcium-rich foods, meeting age-based requirements and using supplements when necessary can help maintain bone density and reduce the risk of bone loss over time. Small, consistent choices—like incorporating calcium into meals and snacks—can add up to stronger bones and better overall well-being.
Frequently Asked Questions
Does calcium improve bone health?
Yes. Getting enough calcium supports bone remodeling and bone density, helping bones stay strong and resilient over time, especially when paired with other healthy habits like physical activity and adequate vitamin D.
What are the signs of calcium deficiency?
Calcium deficiency doesn’t always cause early symptoms, but over time it may lead to low bone density, fractures, muscle cramps or weakness, tingling in the fingers or around the mouth and brittle nails.
Is it better to take vitamin D or calcium for osteoporosis?
Both matter—calcium provides the building blocks for bones, while vitamin D helps the body absorb and use calcium effectively. They work best together rather than replacing one another.
