Can Your Calcium Cause Constipation?

Updated: November 7, 2022

Drinking Water

Reviewed By:
Dr. Liz Lipski – AlgaeCal Scientific Advisory Board Member
PhD, CNS, FACN, IFMP, BCHN, LDN
Professor and Director of Academic Development, Nutrition programs in Clinical Nutrition at Maryland University of Integrative Health.

Why Calcium Supplements Cause Constipation | Top 8 Causes of Constipation | Too Much Supplemental Rock Calcium | Too Much Supplemental Iron | Too Much Sugar and Unhealthy Fats | Lack of Physical Activity | Imbalanced Gut Bacteria | Certain Medications | Lack of Water | Lack of Magnesium | Natural Remedies for Constipation | Takeaway

So you decided to show your bones some love and treat them to some calcium. But after a week or so of taking calcium supplements you notice your stomach’s cramping like you binged on bad takeout. Oh, and let’s not even get into the gas and bloating. So now maybe you’re wondering, “Does calcium cause constipation?”

If so, you’re not alone. Many women and men ask this question. After all, 43% of the American population uses a calcium supplement.1 So it’s likely that there are plenty of upset tummies out there. 

But discomfort aside, these annoying issues are problematic. After all, they can keep you from taking your recommended daily dosage of calcium. Why would you want to feel sick to your stomach, right?

After reading this post, you’ll know how to avoid all these problems and not have to worry about missing your dosing schedule.

Why Do Calcium Supplements Cause Constipation?

Watch the video below or read the transcript here as Lara Pizzorno, Bone Health Expert dives in further to this common question. And don’t forget to continue reading for more insight on how to avoid constipation when taking calcium.

Top 8 Causes of Constipation

1. Too Much Supplemental Rock Calcium

The most common type of calcium and the one that causes the most gastrointestinal discomfort is from rock. It’s described on your label as ‘calcium from calcium carbonate‘ or calcium citrate. This is why rock is used as the main component in antacids like Tums. It works great if you suffer from acid reflux and heartburn – but your digestive system pays the price! If stomach acids aren’t there to churn and break down your food, then it makes sense that constipation, bloating, gas, and cramps will result.

According to a 5-year, double-blind, placebo-controlled study,2 the occurrence of constipation was increased with the use of calcium carbonate (among 1,460 participants, 13.4% of the calcium group experienced constipation; 9.1% of the placebo group experienced constipation).

So why do we eat rock calcium? Because rocks are cheap, rich in calcium (40%)3 and capable of slowing bone loss. See, we naturally lose about 1% of our bone per year after age 35. For decades, rocky calcium carbonate has cut that bone loss down by a little bit.

Rock Calcium

But that wasn’t without its drawbacks. For instance, in several random control trials4 participants receiving calcium reported higher rates of gastrointestinal issues (GI). These problems were described as: 

  • constipation 
  • excessive abdominal cramping 
  • bloating 
  • upper GI events 
  • GI disease 
  • GI symptoms 
  • severe diarrhea or abdominal pain

These gastro issues happen because the alkaline calcium carbonate neutralizes your stomach acids. If stomach acids aren’t there to digest your food and improve mineral absorption, then it makes sense that constipation, bloating, gas, and cramps will result. 

Then there’s the fact that some people are getting more than their recommended dietary allowance for calcium5 because they aren’t compensating for the calcium they get in their food each day. This can also lead to gastrointestinal issues. 

2. Too Much Supplemental Iron

Iron supplements6 are notorious for causing constipation. And that’s why many people don’t follow through with their supplementation.

3. Too Much Sugar and Unhealthy Fats

Consuming too much sugar and/or unhealthy fats feeds unhealthy bacteria in your gut and causes inflammation. And when the intestinal tract swells with inflammation, it’s difficult for food to move through it. Sugar and fats also can displace high fiber foods, leading to constipation.

Tip: Reduce or eliminate foods with added sugar and refined carbohydrates. The same goes for unhealthy fats. Avoid fried foods as much as possible, which also tend to contain refined carbohydrates. Also, swap out unhealthy fats for naturally-occurring healthy fats that have a soothing, inflammation-reducing effect. These can be found in plant-based oils, seeds, nuts and fatty fish.

4. Lack Of Physical Activity

If you ever undergo a medical procedure or end up in the hospital, one of the first things the medical team will do to get you on the mend is help you go for a walk. That’s because we are designed to be on the move and our digestion depends on it.Walking helps move and massage the food in the digestive tract, using gravity to help move it along. Yoga, jogging, Pilates, and the like will all have the same benefits. 

They also help strengthen your muscles, including the intestinal tract, giving you greater ability to move things both inside and outside your body.

Tip: Get up and get moving as often as possible. Take a walk after meals and try to take a couple 5-to-10 minute walking breaks during the work day. Prolonged periods of sitting are bad for digestion, mood, and overall health.

Physical Activity

5. Imbalanced Gut Bacteria

We all get by with a little help from our friends, including the healthy bacteria that make digestion and proper nutrition possible. Healthy bacteria help break down food to extract maximum nutrition and keep it moving along.

6. Certain Medications

The list of medications that can cause constipation7 is lengthy. But some of the top offenders are opioids, NSAIDs, antihistamines, antacids, blood pressure medications and diuretics.

Tip: Follow your healthcare provider’s instructions relating to your medications, but reach out to get more information and solutions regarding constipation. Eat a healthy, fiber-rich diet full of fruits, vegetables, seeds, nuts, legumes and whole grains. Additionally, exercise regularly, drink plenty of water and get plenty of sleep.

7. Lack of Water

Water is vital for healthy digestion. Dehydration wreaks havoc on the human body, including the digestive tract. When you’re dehydrated, your body will conserve as much water as possible for cerebral fluid, blood volume, and respiration.

8. Lack of Magnesium

Magnesium is needed to relax muscles, including those of the gastrointestinal tract. It’s also needed to properly absorb and utilize calcium and vitamin D. Low magnesium intake8 causes a host of health problems, including constipation, irritability, tense muscles, and sensitivity to noise. About half of the American public is magnesium deficient.

Natural Remedies for Constipation

When it comes to constipation, fiber is your friend. Aim for 25-30 grams of fiber daily by eating fiber-rich foods such as fruits, vegetables, legumes, nuts and whole grains. 

Another way to keep your gut happy is to give it a boost of healthy bacteria. Consume probiotic foods such as kefir, yogurt, kimchi, sauerkraut, kombucha and homemade shrubs.

Gut Health

Also, make sure to eat a variety of magnesium-rich foods throughout the day, every day. This includes dark-green vegetables, whole grains, beans, nuts and seeds. As Lara mentioned, calcium and magnesium work together. 

If you really want to get things moving, add some kiwi to your diet. It’s been reported that it eases constipation9 as well as prunes and psyllium powder. Plus, it’s better tolerated.

Of course, you know it’s not enough to simply eat healthy foods — you have to avoid eating unhealthy ones too. So reduce or cut fried foods along with foods that have added sugar and refined carbohydrates. 

The same goes for unhealthy fats. Swap them out for naturally-occurring healthy fats that have a soothing, inflammation-reducing effect. These can be found in plant-based oils, seeds, nuts and fatty fish.
Remember to drink 8 to 10 glasses of water every day. Avoid sugary drinks and/or those with toxic food additives. Limit caffeine consumption to 2 to 3 cups of caffeinated beverages a day. Additionally, exercise regularly and get plenty of sleep.

Takeaway

Constipation is an unwelcome side-effect. But don’t lose sight of why you started taking a calcium supplement in the first place — bone health. 

So don’t give up on taking calcium supplements. Instead, try a natural, plant-based calcium supplement. 

It will be much easier on your stomach. And, unlike traditional rock-based calcium supplements, plant-based calcium can make your bones stronger because it contains all the nutrients your bones need. 

After all, bone loss isn’t a loss of calcium. It’s a loss of all the minerals in your bones. So if your rock-based calcium supplement contains only calcium, that’s bad news. You’re missing 12 vital bone-supporting minerals. 
The best calcium supplement will provide you with all the nutrients your bones need — minus the unwanted side-effects like constipation, gas or bloating!

Calcium Supplement

When looking at calcium supplements, consider these factors:

True Cost: If your calcium supplement is just calcium alone or calcium and vitamin D it is not enough. Your bones are made up of much more than that! They need magnesium, vitamin K2, D3, C, boron, and trace minerals. Buying all of those separately is expensive and a hassle. Instead, get an all-in-one bone formula.

Amount of Calcium: Remember that your body can only absorb 500 mg of calcium at a time. Anything beyond that will make you feel sick to your stomach and lead to constipation. In addition to constipation, too much calcium at once or over time has potential health risks like calcium depositing into soft tissues and kidney stones. AlgaeCal Plus is more effective at a lower dose, compared to higher amounts in other calcium supplements.

Plus, it contains the vitamin K2, which directs calcium straight to your bones and keeps it out of your arteries! And it has magnesium in the proper ratio of 2:1 (2 parts calcium to every part magnesium). 

As you’ve now learned, magnesium is a natural laxative — which will balance the constipating effects of calcium. And it also has bone-building properties. 

What’s more, the minerals are “pre-digested” by the plant making them more body-friendly! That’s why this rare marine algae can help you stay constipation-free.

References

  1. Regan L Bailey, Kevin W Dodd, Joseph A Goldman, Jaime J Gahche, Johanna T Dwyer, Alanna J Moshfegh, Christopher T Sempos, Mary Frances Picciano. “Estimation of total usual calcium and vitamin D intakes in the United States.” The Journal of Nutrition. (2010) doi: 10.3945/jn.109.118539
  2. Kelvin Li, Xia-Fang Wang, Ding-You Li, Yuan-Cheng Chen, Lan-Juan Zhao, Xiao-Gang Liu, Yan-Fang Guo, Jie Shen, Xu Lin, Jeffrey Deng, Rou Zhou, and Hong-Wen Deng. “The good, the bad, and the ugly of calcium supplementation: a review of calcium intake on human health.” Clinical Interventions in Aging. (2018). doi: 10.2147/CIA.S157523
  3. Douglas C. Bauer, M.D. “Calcium Supplements and Fracture Prevention.” The New England Journal of Medicine. (2014). doi: 10.1056/NEJMcp1210380
  4. I. R. Reid, S. M. Bristow, M. J. Bolland, “Calcium supplements: benefits and risks.” Journal of Internal Medicine. (2015). doi: 10.1111/joim.12394
  5. https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/ 
  6. Lindsay H. Allen. “Iron Supplements: Scientific Issues Concerning Efficacy and Implications for Research and Programs.” The Journal of Nutrition, Volume 132, Issue 4, (April 2002), Pages 813S–819S, https://doi.org/10.1093/jn/132.4.813S
  7. Christopher N Andrews, MD MSc FRCPC1 and Martin Storr, MD. “The pathophysiology of chronic constipation.” Canadian Journal of Gastroenterotology. (2011). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3206564/ 
  8. American Osteopathic Association. “Low magnesium levels make vitamin D ineffective: Up to 50 percent of the US population is magnesium deficient.” ScienceDaily. (2018). www.sciencedaily.com/releases/2018/02/180226122548.htm 
  9. Samuel W Chey, William D Chey, Kenya Jackson, Shanti Eswaran. “Exploratory Comparative Effectiveness Trial of Green Kiwifruit, Psyllium, or Prunes in US Patients With Chronic Constipation.” The American Journal of Gastroenterology (2021). doi: 10.14309/ajg.0000000000001149.

Article Comments

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  1. gina richards

    June 20, 2013 , 4:00 am

    Thank you for the information. i have been prescribed the powdery chewable tablets that you describe as ‘rock’ for all the years since diagnosis by scan in jan 2006 age 50. i most certainly will try algae cal. also thank you for the dietary info, i will be following a healthier diet from now on. some of your diet plan was already on my weekly agenda, but now i have seen some that i could introduce for variety. much appreciated.

  2. AlgaeCal

    June 25, 2013 , 2:31 pm

    Anytime, Gina.

    We’re here to help. Let us know if you need anything else, OK?

  3. Toni Tobin

    November 19, 2019 , 7:33 pm

    Let me know when you make this in a gummy. I don’t do pills.

  4. Blaire AlgaeCal

    November 20, 2019 , 12:13 pm

    Thanks for reaching out and letting us know, Toni! If you have difficulty swallowing, you can twist or cut open the capsules and sprinkle the powder on cold food and/or beverages like yogurt, smoothies, apple sauce, etc.

    AlgaeCal powder is tasteless but the texture is a little gritty because it is rich in minerals. Some of the minerals are not 100% water soluble and this is the reason why it is best to be mixed with foods or beverages that have a thicker consistency. Hope that helps! 🙂

    – Blaire @ AlgaeCal

  5. Kathy

    August 29, 2014 , 8:34 pm

    Hi there I have been taking calcium citrate and magnesium glycinate and I am having severe constipation. I was wondering if the calcium in the article would work for me. I can’t goon this way with severe constipation.
    Thanks, Kathy

  6. Monica

    September 2, 2014 , 9:38 am

    Hi Kathy,

    AlgaeCal is a plant-based calcium so you should not get any side effects such as constipation.You can try AlgaeCal and if you experience constipation you can call us within 1 month and we offer a full refund on the opened bottle minus the shipping costs.

    – Monica @ AlgaeCal

  7. Jan cutler

    August 29, 2016 , 7:40 am

    I think you have Just solved my problem! Where can I purchase AlgaeCal? Currently I am taking 1 , 60g calcium plus w/ magnesium in the am and one in the pm plus an am vitamin D , 1000iu.

    Thank you

  8. Monica

    August 29, 2016 , 9:33 am

    Hi Jan,

    Wonderful to hear! You can buy AlgaeCal online here: https://www.algaecal.com/products/algaecal-plus/

    Let me know if you have any further questions.

    – Monica @ AlgaeCal

  9. Sarah

    December 14, 2016 , 6:14 am

    Can you by this in the uk?

  10. Monica

    December 14, 2016 , 8:39 am

    Hi Sarah,
    You cannot buy AlgaeCal in stores, but you can buy AlgaeCal online and we ship to the UK. For more information on international shipping go here: https://www.algaecal.com/shipping-returns/

    – Monica @ AlgaeCal

  11. Nikki DeSimio

    March 4, 2017 , 6:33 am

    Hi,I would love to try AlgaeCal but I have a difficult time swallowing pills. Are they large?

  12. Monica

    March 4, 2017 , 8:43 am

    Hi Nikki,
    You can actually pull apart AlgaeCal capsules and sprinkle the powder into foods like yogurt, oatmeal and drinks like juices and smoothies if you find swallowing them difficult.
    – Monica @ AlgaeCal

  13. treva silverman

    July 5, 2017 , 4:05 pm

    Thanks for such helpful information.
    I’d like to know about pulling the capsules apart and sprinkling them on yogurt. Will it have a taste when sprinkling them? In other words, will it change the taste of the yogurt? What other foods will it do well sprinkling on? Thanks so much.

  14. Monica

    July 6, 2017 , 9:21 am

    Hi Treva,

    The taste is neutral so it won’t alter the flavor of your yogurt. Applesauce, smoothies, and oatmeal are also good alternatives. Just remember to mix well so it’s not all clumped together in your food :).

    – Monica

  15. Joyce Loera

    July 15, 2017 , 11:04 am

    I just increased Strontium Plus from one capsule to two and WOW!, I now have great bowel movements. I’m so happy…………

  16. Monica

    July 17, 2017 , 8:19 am

    Hi Joyce,

    Thanks for sharing! That’s great 🙂

    – Monica

  17. Barbara

    October 18, 2017 , 12:43 pm

    WhaWWh

  18. Sheila

    October 28, 2017 , 1:37 pm

    I started the algaeCal 6 mo trial. Im not sure when but about month 4 or so small bumps slowly appeared along my spine. First I ignored it, but they persisted. y medical professional concluded that ! Had developed an adult onset sensitivity to shellfish. I had to stopped AlgaeCal, the itchy bumps disappeared. At the same time I ceased the Strontium supplement.
    Has anyone else experience the same reaction? After studying AlgaeCal findings I was sorry to stop the program.
    I continue AlgaeCal Omega-3.

  19. Lara Pizzorno

    October 31, 2017 , 11:10 am

    Hi Sheila,

    This seems strange as AlgaeCal does not contain shellfish in any form, and no such side effect has ever been reported in any of the human research studies conducted using AlgaeCal Plus and Strontium Boost. Algas calcareas is a plant, a marine algae. Since it’s possible you had an exposure to shellfish from something else, and because AlgaeCal Plus is so effective in helping healthy bone to rebuild, it might be worth a trial to see if you were actually reacting to AlgaeCal. Hopefully, you still have your AlgaeCal Plus products at home? Try to think about what other exposures you might have had — a new laundry soap? body lotion? shampoo? Do you have a garden? After harvesting the produce from our vegetable garden a few days ago, I developed a contact dermatitis, most likely from the radishes. Definitely NOT from AlgaeCal, which I have now been taking every day for close to 5 years and will continue to take for the next 50 years or so (I just turned 69, so that will make me 120 :-)).

  20. Pat

    July 23, 2018 , 4:51 pm

    Does algaecal cause gas?

  21. Jenna AlgaeCal

    July 31, 2018 , 10:36 am

    Hi Pat,

    Good question! Like this article touches on, many people report discomfort with over the counter calcium and fortified calcium foods/beverages. This can be due to the calcium coming from a single source/rock based calcium such as calcium carbonate, or perhaps a calcium/magnesium imbalance causing digestive discomfort. AlgaeCal is extremely well tolerated across the board, as all of its calcium comes from a whole food, plant source. We get a lot of feedback from people who have switched to AlgaeCal and tell us they find it body-friendly and easy on their system – with no flatulence issues!

    Should there ever be any discomfort, we offer a full, one year product satisfaction guarantee on all of our products, and we stand by this 100%! We want you to be happy in what you are taking and trust that the products will not cause you any digestive issues. There is more information available on this here.

    Feel free to give us a call at 1-800-820-0184 if you have any questions!

    – Jenna @ AlgaeCal

  22. Paula

    May 4, 2019 , 3:16 pm

    I am taking AlgaeCal but I’m also continuing my dairy (4 servings a day — 2 cups of milk and 2 cups of Greek yogurt.) I try not to drink much milk when I take my AlgaeCal, but I do usually end up drinking it within an hour of taking the AlgaeCaL. I was not constipated at all when I just did dairy, but now I’m finding that I tend to be constipated. Should I cut back on my AlgaeCal if I’m going to be consuming that much dairy? I do hate to cut back on my dairy, since my DEXA numbers improved this past year (before the AlgaeCal — I’m hoping for even better this coming year!)

  23. Jenna AlgaeCal

    May 6, 2019 , 3:57 pm

    Hi Paula,

    It sounds like you might not be getting enough magnesium to balance out all of the calcium in your diet! You see, AlgaeCal contains a specific 2:1 calcium to magnesium ratio as this is the balance found in most of our bodies. When you’re consuming a large amount of calcium from dairy, you may require additional magnesium as well — so you could try supplementing with additional magnesium to see how that feels.

    We definitely wouldn’t suggest cutting back on AlgaeCal as it contains all of the other essential nutrients for bone health that dairy products do not! We’ll be super excited to hear how your next DEXA scan goes with the added support of trace minerals, vitamins C, D3, K2, and more.

    If you have any questions don’t hesitate to give us a call at 1-800-820-0184! ❤️

    – Jenna @ AlgaeCal

  24. Rosie Alleva

    June 12, 2019 , 4:28 am

    Can you please show the size or tell the measurement of this pill. When asked, the common response is that it can be pulled apart and sprinkled on food. How does it compare to the large calcium pills most doctors recommend?

  25. Jenna AlgaeCal

    June 12, 2019 , 8:37 am

    Hi Rosie,

    AlgaeCal’s soft veggie capsules are about 0.75 inches long, 0.25 inches wide, and are designed to be easily swallowed! That being said, many members of our community who have difficulty swallowing capsules simply use the powder. As you mentioned, the capsules can easily be twisted open and sprinkled into foods like smoothies, yogurt, and oatmeal. We just don’t recommend hot foods or drinks to avoid denaturing the vitamins. Hope that helps!

    – Jenna @ AlgaeCal

  26. Beverly Raine

    July 7, 2020 , 9:11 am

    My husband takes PPI daily for heartburn, the doctor recommends taking calcium because this medication depletes calcium. I know women need more calcium than men. Is your product too much calcium for a man?

  27. Megan AlgaeCal

    July 7, 2020 , 10:04 am

    Hi Beverly, good question!

    AlgaeCal is suitable for both women and men. A daily dose of AlgaeCal Plus provides 720 mg of calcium. We recommend meeting your daily requirements by adding calcium-rich foods to the diet and have a list your husband may find helpful here!

    Hope this helps and feel free to give us a call at 1-800-820-0184 with any further questions 🙂

    -Megan @ AlgaeCal

  28. Jean

    October 19, 2020 , 3:44 am

    Hi
    I’ve just recently had a total thyroidectomy and I am on 1800 mg of calcium carbonate 3 x a day until my retransplanted parathyroid glands take. Constipation is a huge issue for me. What would the equivalent does of your product/or the right product from your range be?
    Thank you

  29. Megan AlgaeCal

    October 20, 2020 , 12:48 pm

    Hi Jean, thanks for reaching out!

    For specific medical conditions, we recommend consulting your doctor for their best recommendation. We have an excellent information sheet you can share with them here.

    Hope this helps! If you have any questions before or after you appointment, don’t hesitate to give us a call at 1-800-820-0184 ❤️

    -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, B.Phil.,(oxon.) - 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.,