Calcium: Essential for Bone Health and Beyond

By Jennifer Youngren, NDTR

When you think about calcium, strong bones and teeth might be the first things that come to mind. But this mineral does so much more! Calcium is crucial for muscle contraction, heart health, nerve signaling, and even blood clotting. Let’s dive into why calcium is essential, how to get enough, and how it impacts your overall health.

What Is Calcium’s Role in Bone Health?

Calcium is responsible for supporting the skeletal structure and function in bones. Consuming adequate calcium helps us reach our genetically determined peak bone mass, usually around age 30. It is important to continue to consume calcium as we age to maintain bone density.

About 98% of your body’s calcium is stored in your bones and teeth, acting as a reservoir to maintain your body’s essential functions. But here’s the catch: if you don’t consume enough calcium through your diet, your body takes it from your bones, which can lead to a condition called osteoporosis.

Many factors contribute to bone loss, but the most common culprit is not consuming adequate dietary calcium. When there is an inadequate intake of calcium from our diet, our bodies then look to stored calcium from our bones and teeth. This can result in the bone becoming porous, little holes can form in the bone and make it more susceptible to breakage (BHOF.)

What Is Osteoporosis?

Osteoporosis weakens bones, making them porous and prone to fractures. Risk factors include:

Low dietary calcium intake
Family history of osteoporosis
Eating disorders
Early menopause or amenorrhea (low estrogen levels)
Smoking, excessive alcohol, and caffeine
Certain medications like SSRIs and heparin
Genetic factors (e.g., being female, Asian, or Caucasian with a slender frame)

According to the Bone Health and Osteoporosis Foundation, twenty percent of seniors who break a hip die within a year due to complications and often, long-term rehabilitation is required for those who suffer from breakage. Maintaining bone density is critical at every stage of life!

Take this QUIZ to see if you are at risk for developing osteoporosis.

Preventing Bone Loss: Tips for Strong Bones

The good news? You can take simple steps to keep your bones strong and healthy:

Prioritize Calcium and Vitamin D
- Calcium builds bone strength, while Vitamin D helps your body absorb calcium.
- Spend 8-10 minutes in sunlight several times a week (hands and face) or incorporate Vitamin D-rich foods into your diet.
Stay Active
- Weight-bearing exercises like walking, dancing, or strength training boost bone health and improve balance, reducing the risk of falls and fractures.
Choose Calcium-Rich Foods
- Dairy: Milk and milk products such as yogurt, ice cream, cream soups, and custards
- Non-Dairy: Plant-based milks and orange juice fortified with calcium
- Tofu and edamame
- Vegetables: Leafy greens like bok choy and broccoli
- Fish: Canned salmon or sardines with bones
- Fortified cereals
- Nuts and Seeds: Almonds, Brazil nuts, chia, and sesame, including tahini
- Oranges
- Corn tortillas
  
  While milk and dairy products are considered the top choices for calcium in the western diet, they are not the only dietary source. In fact, one Harvard study found that leafy greens like Bok Choy (160 mg per cup) to be more bioavailable to the body than cow’s milk.

Calcium and Chronic Diseases

Calcium isn’t just about bones! Research shows it plays a role in preventing other health issues:

Colon Cancer Prevention
Current research shows that lowered intake of calcium increased the incidence of colorectal cancer, while higher intakes of calcium have been shown to lower a person’s risk for developing colon cancer. In a recent study, men and women who were given a high intake of calcium (700-1,000 mg per day), showed a reduced risk of colorectal cancer than those given less than 500 mg a day. Intakes exceeding 1,200 mg per day showed no further benefit (National Cancer Institute.)
Calcium and kidney stones:
Kidney stones are often the result of dehydration and high intake of sodium and oxalate rich foods. For individuals with normal kidney function, calcium poses no threat to developing kidney stones when kept under 2,000 mg per day. According to the American Journal of Clinical Nutrition, urine calcium has been shown to increase when there is a decrease in dietary calcium, raising the risk for kidney stones. When oxalates are consumed with dietary calcium they bind together in the stomach and intestines, as opposed to binding together while urine is produced in the kidneys, reducing the instance of kidney stones (National Kidney Foundation.)

Contrary to popular belief, dietary calcium can help prevent kidney stones. Calcium binds to oxalates in your digestive system, keeping them out of your kidneys.

How Much Calcium Do You Really Need?

According to the National Institutes of Health, most adults should aim for 1,000 mg/day. Women over 50 need a bit more—1,200 mg/day—to protect against bone loss. Yet, only 40% of Americans meet these goals.

What About Calcium Supplements?

If you struggle to get enough calcium from food, supplements can help. Here’s what to know:

Types:
- Calcium Carbonate: Affordable and best taken with food.
- Calcium Citrate: Easier to absorb, especially if you have low stomach acid, and doesn’t require food.
Dosage Tips:
- Take no more than 500 mg at once for better absorption.
- Space out doses throughout the day.

There are two main forms of calcium supplements, calcium carbonate and calcium citrate. Calcium carbonate is the most common and affordable out of the two. While both supplements are well-absorbed by the body, calcium citrate can be absorbed more easily, especially for individuals with lower levels of stomach acid. Calcium citrate can also be taken with or without food while calcium carbonate is more efficient when taken with food. It is important to note that calcium absorption is best when dosage does not exceed 500 mg at one time (NIH.)

Keep in mind that supplements can cause mild side effects like bloating or constipation. Always consult your healthcare provider before starting any new supplement.

The Bottom Line

Calcium is a nutritional powerhouse that supports your bones, muscles, heart, and more. Prioritize calcium-rich foods and pair them with Vitamin D for maximum benefits. Whether through diet, supplements, or both, meeting your calcium needs today will help you stay strong and healthy for years to come.

References:

6 easy ways to prevent kidney stones. National Kidney Foundation. (2022, November 4). Retrieved April 19, 2023, from https://www.kidney.org/atoz/content/kidneystones_prevent#:~:text=It%20is%20important%20to%20eat,that%20kidney%20stones%20will%20form.

“Calcium.” The Nutrition Source, 7 Mar. 2023, https://www.hsph.harvard.edu/nutritionsource/calcium/#:~:text=Plant%20foods%20like%20leafy%20greens,about%2080%20mg%20is%20absorbed.

The risk of Kidney Stone Formation: The form of calcium matters. (n.d.). Retrieved April 21, 2023, from https://ajcn.nutrition.org/article/S0002-9165(23)02347-X/fulltext

Quiz: Are You at Risk for Osteoporosis? - Endocrineweb.com.

https://www.endocrineweb.com/conditions/osteoporosis/osteoporosis-symptoms-quiz.

“Calcium and Bone Health: What Plant-Based Eaters Need to Know.” Forks Over Knives, 21 Sept. 2022, https://www.forksoverknives.com/health-topics/calcium-and-bone-health-diet/.

Calcium. The Nutrition Source. (2023, March 7). Retrieved April 19, 2023, from https://www.hsph.harvard.edu/nutritionsource/calcium/#:~:text=Plant%20foods%20like%20leafy%20greens,about%2080%20mg%20is%20absorbed.

Calcium and cancer prevention. National Cancer Institute. (n.d.). Retrieved April 18, 2023, from https://www.cancer.gov/about-cancer/causes-prevention/risk/diet/calcium-fact-sheet

What is the latest recommendation regarding calcium supplements? (n.d.). Retrieved April 19, 2023, from https://www.jandonline.org/article/S2212-2672(17)31007-9/fulltext

What is osteoporosis and what causes it? Bone Health & Osteoporosis Foundation. (2023, February 24). Retrieved April 18, 2023, from https://www.bonehealthandosteoporosis.org/patients/what-is-osteoporosis/

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