How Much Calcium Do I Need Daily?

Published: September 30, 2014
Updated: August 1, 2022


How Much Calcium Do You Need in a Day? | Daily Calcium Requirement by Age | Benefits of Calcium for Bone Health | Risks of Getting Too Little Calcium | How Much Calcium Is Too Much Calcium? | Takeaways

It’s easy to see why people think you can get enough calcium by drinking milk every day. Remember those ‘milk does a body good’ commercials from way back when? For two decades they told us that milk is what makes bones strong. After all, it’s loaded with calcium. 

And, as you know, our bones need calcium to stay strong and healthy. So okay, we get it — we need calcium. But how much?

I’m Lara Pizzorno, author of Healthy Bones Healthy You, and a member of the American Medical Writers Association with 30 years of experience specializing in bone health. And today I’m talking about all things calcium. How much do you need? And are Americans getting enough? Are you getting enough to have healthy bones?

How Much Calcium Do You Need in a Day?

According to the National Health and Nutrition Examination Survey, (NHANES),1 most Americans are not doing a good job of getting enough calcium.

Time with Grandmother

The two groups at risk of not getting adequate amounts of calcium from their diets are children aged 9–18 and then adults aged 51 and older. 

In the group of children aged 9–18, this is especially important because they’re supposed to be accruing 40% of the bone mass they need to carry them through their lives. 

And if they don’t get enough calcium during these important bone-formative years, they’ll be at much higher risk of osteoporosis later. This group of individuals are supposed to get 1,300 mg of calcium a day. But typically their diet supplies a maximum of about 935 mg a day — a serious shortfall.In the group of adults aged 51 and older, the daily calcium requirement is 1,000–1,200 mg. But many in this group are only getting 674 mg of calcium per day from their diet.

Daily Calcium Requirement By Age

Of course, there are several age groups that don’t fall into the 9–18 or 51 and older categories. For a full breakdown of calcium requirements for all age groups, check out the Recommended Dietary Allowances for Calcium2

0-6 months*200 mg200 mg
7-12 months*260 mg260 mg
1-3 years700 mg700 mg
4-8 years1,000 mg1,000 mg
9-13 years1,300 mg1,300 mg
14-18 years1,300 mg1,300 mg
19-50 years1,000 mg1,000 mg
51-70 years1,200 mg1,200 mg
>70+ years1,200 mg1,200 mg

Pregnant and Lactating women between the ages of 19-50 years require 1,000 mg of Calcium and those between the ages of 14-18 require 1,300 mg.

Benefits Of Calcium For Bone Health

As you can see, your body’s need for calcium doesn’t lessen with age. That’s why it’s important to supply your bones with the calcium they need. 

After all, more than 99% of your total body calcium is stored in your bones and teeth,3 where it supports their structure and is ready to be called into action for many other critical functions.

A few of these functions include muscle contraction, the secretion of enzymes and hormones, and sending messages through the nervous system. The amount of calcium in your body fluid and tissues is closely regulated so that these vital body processes function efficiently.

Calcium also brings these benefits to the table:

  • balances blood pressure
  • reduces colorectal cancer 
  • eases PMS symptoms 
  • combats kidney disease 
  • promotes weight loss 
  • promotes dental health

So it’s particularly important to consume enough calcium (and its helper minerals and vitamins such as magnesium, vitamins D3, K2, C, boron, and trace minerals).

Eggs and greens

Risks Of Getting Too Little Calcium

When you don’t get enough calcium or don’t absorb enough, bone breakdown occurs because the body removes the calcium stored in bones to keep more urgent functions going — such as generating a heartbeat.

This is especially problematic for older adults since we begin to resorb more bone much more rapidly as we get older. This is due to the decline in hormones: estrogen in women and testosterone in men.

The estrogen drop-off happens sooner in women. But men also experience a dip in the amount of testosterone they produce. In men, a small amount of testosterone is converted to estrogen. 

And that estrogen is critical for men’s bones. So both genders need to ensure they’re getting enough calcium to make up for the deficits that come with advancing age.

A number of studies have been done that show that calcium supplementation can help make up for this shortfall. 

A very famous calcium researcher named Robert Heaney published a study4 in The Journal of The American College of Nutrition in 2001 that showed that women who did not take calcium supplements lost bone at a rate of 1% per year. But women who did take calcium supplements only lost bone at a rate of 0.014% per year. So that’s about a 100% lower rate of bone loss. Calcium supplementation can really help make up the deficits that we experience with age.

How Much Calcium Is Too Much Calcium?

It’s clear that not getting enough calcium is bad for your bones. But what happens if you get too much calcium? If you’ve ever wondered this, you’re not alone. One of AlgaeCal’s Facebook Community members, Cindy, said:

I have a question about how much calcium is too much. My doctor told me to be careful because too much calcium can cause kidney stones. Is this true with the type of calcium in AlgaeCal?” 

Welcome, Cindy! You’re in the right place! And that’s a great question. 

While you don’t want to exceed the recommended daily allowance for calcium, you also need to pay attention to the form of calcium you take.

AlgaeCal is easier for the body to absorb because it’s a natural plant-sourced calcium. So it’s similar to the calcium you get from eating vegetables such as broccoli, kale, and peas. 

That means it’s the best form of calcium to take. As you may know, your bones are made up of more than just calcium. They’re made up of a matrix of vitamins and minerals. 

And that’s why AlgaeCal contains all 13 known essential bone-supporting minerals (calcium, magnesium, boron, copper, manganese, silicon [silica], nickel, selenium, strontium, phosphorus, potassium, vanadium, and zinc).

Together, all these vitamins and minerals are clinically supported to maintain and improve bone mineral density. Plus, they work together to optimize absorption and transfer calcium directly to your bones rather than soft tissues like your arteries or kidneys. 



As you know, taking an adequate amount of calcium daily is key to having strong, healthy bones. Of course, as you age, your bones need more of a calcium boost. So focus on eating calcium-rich foods with plenty of bone-friendly nutrients. 

And take a daily calcium supplement. Remember, it isn’t necessary to reach for the highest dosage you can find. 

Consider that a recent meta-study has shown that lower dose calcium supplementation, combined with vitamin D, was most effective at preventing osteoporosis-related fractures, whereas high dose (1,000 mg) calcium supplementation was not. 5,6,7

In one human study,8 three groups of post-menopausal women each took different AlgaeCal formulations with all groups increasing bone density at one year.  

The smallest average increase among the 3 groups was 1.3% — an extraordinary result. So if you’re really serious about staying on top of your bone health, take a daily calcium supplement like AlgaeCal Plus.

Hope this has been helpful and let us know in the comments if you have any questions or concerns about your calcium intake!


  3. “Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride.” National Library of Medicine (1997). 
  4. Heaney, R, Dowell, S, et al. “Absorbability and Cost Effectiveness in Calcium Supplementation.” Journal of the American College of Nutrition. Vol. 20 (2001) Issue 3.
  5. Bischoff-Ferrari HA, Willett WC. “Comment on the IOM Vitamin D and Calcium Recommendations.” Harvard School of Public Health: The Nutrition Source (2010).
  6. Zoler ML. “High Vitamin D Intake Linked to Reduced Fractures.” Family Practice News (2010).
  7. Bischoff-Ferrari HA, Orav EJ, Willett, WC, et al., “A Higher Dose of Vitamin D is Required for Hip and Non-vertebral Fracture Prevention: A Pooled Participant-based Meta-analysis of 11 Double-blind RCTs.” The American Society for Bone and Mineral Research 2010 Annual Meeting (2010).
  8. Gilbert R. Kaats, Harry G. Preuss, Harry A. Croft, Samuel C. Keith, Patti L. Keith. “A Comparative Effectiveness Study of Bone Density Changes in Women Over 40 Following Three Bone Health Plans Containing Variations of the Same Novel Plant-sourced Calcium.” Int J Med Sci (2011). doi: 10.7150/ijms.8.180   

Article Comments

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  1. Georgiana

    September 30, 2014 , 3:31 pm

    I was unable to absorb calcium carbonate or calcium citrate. Not until I used Algae Cal and Strontium did I see an increase in my bone density. Thank Goodness

  2. Monica

    September 30, 2014 , 3:47 pm

    Hi Georgiana,

    Thank you for sharing your story. It’s great to hear that AlgaeCal Plus and Strontium Boost increased your bone density!

    – Monica @ AlgaeCal

  3. Florence

    December 2, 2014 , 7:58 am

    I have osteopenia and had a hip fracture when I took a fall a couple of years ago. I was told by one MD to take Calcium Citrate and another told me not to take it because we get enough Calcium in our diet. (My father had calcium deposits when he died in surgery for an angioplasty at age 75.) What I have read about your product makes sense and I am interested but it is out of my budget at this time. Is there any way of earning your product. I would like to see an improvement in my bone density.

  4. Monica

    December 2, 2014 , 8:40 am

    Hi Florence,

    Thank you for your interest in AlgaeCal. Unfortunately, we do not offer a way to earn our product, but we do offer a significant discount if you buy multiple bottles of AlgaeCal and is explained on our products page.

    – Monica @ AlgaeCal

  5. Sandra Finch

    December 2, 2014 , 9:20 am

    What about the Calcium/Magnesium ratio? What kind of magnesium is best since I have recently found out I am deficient in magnesium.

  6. Monica Lam-Feist

    December 3, 2014 , 10:21 am

    Hi Sandra,

    With regards to calcium and magnesium, a 2:1 ratio of calcium to magnesium is necessary for proper absorption of calcium. The human body has a natural ratio of 2:1 calcium to magnesium and this is the same in AlgaeCal Plus. Too much magnesium will compete with calcium for absorption, but with this 2:1 ratio, it will not as it is the most efficient ratio.

    As for what kind of magnesium is best, there are no significant studies that have proven any one form of magnesium is better than the others. The magnesium we used in AlgaeCal’s study is magnesium oxide combined with magnesium carbonate. Because magnesium must be bound with another substance to be absorbed adequately, we chose these forms because their molecular mass is higher.

    Let me know if you have any other questions,

    – Monica @ AlgaeCal

  7. Mary Ulsh

    December 2, 2014 , 11:18 am

    The best way to get the calcium a person needs is taking whole food supplements. Also eating food like cheese, yogurt and vegetables like broccoli and kale. Regular calcium supplements do not work. I have taken calcium supplements for years and they did nothing for me. When I can I will buy AlgaCal as it is whole food supplement.
    Sincerely, Mary Ulsh

  8. Monica

    December 2, 2014 , 11:52 am

    Hi Mary,

    Thank you for your comment! You’re right, it’s important to supplement as well as eat calcium-rich foods for your bone health.

    – Monica @ AlgaeCal

  9. April

    December 3, 2014 , 2:01 pm

    I thought if you got too much calcium it clogs your arteries. I overheard a doctor say that you have to track your calcium intake as to not “overdo” it but eating too much calcium in food and taking supplements also. Excess calcium ends up in your blood and causes problems?Can you address this? Thank you.

  10. Monica

    December 3, 2014 , 3:24 pm

    Hi April,

    Great question. AlgaeCal is easier for the body to absorb because it is a natural plant sourced calcium similar to calcium you get from eating vegetables such as broccoli, kale and peas. Studies have shown that calcium from whole foods like AlgaeCal, does NOT increase heart attack risks because foods that naturally contain calcium also supply other minerals.

    Your bones are not solely made up of calcium, but are made up of a matrix of vitamins and minerals. That is why AlgaeCal has additional magnesium, boron, vitamin K2 and vitamin D3 as well as 70 other trace minerals, which optimize absorption and transfer calcium directly to your bones rather than soft tissues like arteries, kidneys etc. All these factors translate to an absorption rate of 97% for AlgaeCal. AlgaeCal is also much safer for you because it is more effective at a lower dosage. In our human study, all 176 participants were able to increase their bone mineral density of up to 1% in 12 months with taking 720 mg of calcium from AlgaeCal daily.

    I hope this answered your question. If you have any others, please do not hesitate!

    – Monica @ AlgaeCal

  11. Goretti Ferreira

    January 2, 2017 , 5:44 am

    Hello I like to know if Alga Cal and strontium will help someone that already have significant bone loss, or that supplement is good to prevent that.

  12. Monica

    January 2, 2017 , 9:11 am

    Hi Goretti,

    AlgaeCal Plus and Strontium Boost are clinically supported to INCREASE bone density in people who are suffering bone loss. If you are looking to maintain your current bone density, we recommend just using AlgaeCal Plus.

    – Monica @ AlgaeCal

  13. Danish Riaz

    January 31, 2019 , 2:25 am

    Your math here is incorrect and misleading. Please explain how going from 1% to 0.014% is a 1000% difference? Its a 71.42% difference.

    “A very famous calcium researcher named Heaney, published a study in The Journal of The American College of Nutrition in 2000 that shows that women who did not take calcium supplements lost bone at a rate of 1% per year. But women who did take calcium supplements only lost bone at a rate of 0.014% per year. So that’s about a 1000% lower rate of bone loss. Calcium supplementation can really help make up the deficits that we experience with age.”

  14. Jenna AlgaeCal

    February 4, 2019 , 10:56 am

    Hi Danish,

    You’re right, we had a typo there! The difference should actually be 100%, and I’ve updated that in the blog post. You can use this online calculator to see how we got that number. 🙂

    – Jenna @ AlgaeCal

  15. frances mccaffrey

    October 4, 2020 , 9:05 am

    Hello could you please tell me if calcium tablets should be taken with the algaecal or is it not necessary ,as the doctor has advised my mum to do so.

  16. Blaire AlgaeCal

    October 6, 2020 , 11:33 am

    Hi Frances,

    Thanks for reaching out!

    Once starting AlgaeCal Plus, additional calcium supplementation is not necessary. Feel free to give our Bone Health Consultants a call at 1-800-820-0184 if you have further questions! ?

    – Blaire @ AlgaeCal

  17. BJ

    December 29, 2020 , 7:40 am

    Would adding 600mg of magnesium to my algaecal and strontium daily doses help or hurt my bones? The mag def helps me with digestion and staying regular. Thx

  18. Megan AlgaeCal

    December 29, 2020 , 2:14 pm

    Hi BJ!

    We recommend aiming for a 2:1 ratio of calcium to magnesium each day. As the daily recommendation for calcium is 1200mg, this would mean 600mg of magnesium. Keep in mind, however, that AlgaeCal Plus provides 350mg of magnesium in a daily serving. You may want to start with a lower additional dose of magnesium.

    Hope this helps and if you have any other questions, feel free to reach out to our Bone Health Consultants at 1-800-820-0184 (USA & Canada toll-free). ❤️

    -Megan @ AlgaeCal

This article features advice from our industry experts to give you the best possible info through cutting-edge research.

Prof. Didier Hans
PHD, MBA - Head of Research & Development Center of Bone Diseases, Lausanne University Hospital CHUV, Switzerland,
Lara Pizzorno
MDiv, MA, LMT - Best-selling author of Healthy Bones Healthy You! and Your Bones; Editor of Longevity Medicine Review, and Senior Medical Editor for Integrative Medicine Advisors.,
Dr. Liz Lipski
PhD, CNS, FACN, IFMP, BCHN, LDN - Professor and Director of Academic Development, Nutrition programs in Clinical Nutrition at Maryland University of Integrative Health.,
Dr. Loren Fishman
MD, PhD - Medical Director of Manhattan Physical Medicine & Rehabilitation and Founder of the Yoga Injury Prevention Website.,
Dr. Carole McArthur
MD, PhD - Professor of Immunology, Univ. of Missouri-Kansas City; Director of Residency Research in Pathology, Truman Medical Center.,