Calcium Citrate vs Carbonate

Calcium Citrate vs Carbonate

One question we get quite a bit here at Supplement Warehouse is whether Calcium Citrate or Calcium Carbonate is a better form for our customers. In this blog post, our team wanted to break down the differences between each.

First, let's dive into why you should you either.

Calcium Citrate:

  • Best for older adults

  • People with low stomach acid

  • Anyone using antacids or PPIs

  • Long-term, well-tolerated use

Calcium Carbonate:

  • Best for young adults with good digestion

  • Higher calcium per dose when taken correctly

  • Short-term supplementation

Absorption

Calcium Citrate wins here. This one absorbs well with or without food. Calcium Carbonate needs to be taken with food.Calcium Citrate is also best for older adults they may have low stomach acid, which can hurt absorption.

Pill Size

Calcium Carbonate normally are larger than Citrate. This is because more Calcium Carbonate is needed per pill due to the lower absorption rate. So if you are someone that doesn't like large pills or tablets, go with Calcium Citrate. This is why most of the time you find the Calcium Carbonate in a powder form so you can mix it with water or your favorite beverage.

Tolerance & Side Effects

Calcium Citrate tends to have less side effects. Calcium Carbonate has a better chance for causing constipation, gas, bloating and even kidney stones (if you are prone to them).

Cost

Now this is an area where Calcium Carbonate wins. It is definitely cheaper to use than the Citrate.

Conclusion

Now that you have a better idea of the benefits of each, let's conclude with who should use what.

Choose Calcium Citrate if...

  • You have digestion issues or take acid reducers
  • You're older or postmenopausal
  • You want more flexible dosing (with or without food)

Choose Calcium Carbonate if...

  • You want a higher dose in fewer pills (or take powder)
  • You tolerate it well and want to save money
  • You take it with meals and have no GI problems

If you are looking for each, we sell both versions here at Supplement Warehouse. We recommend Now Foods Calcium Citrate and Now Foods Calcium Carbonate.

Jun 3rd 2025 Jeff Moriarty
Author
Jeff Moriarty
Jeff has been in the fitness and supplement industry for almost 20 years. He is an avid bodybuilder and helps others with lifting techniques, as well as the best vitamins and supplements they should take for the goals they have. You can find him on LinkedIn and Youtube.
Jeff Moriarty

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†The content of this blog post is intended solely for reference and entertainment purposes. We do not offer medical advice or specific guidance regarding the products discussed. Our insights are based on a combination of anecdotal experiences, online studies/reviews, manufacturer details, and customer feedback. While we strive to present accurate and current information, we cannot assure its completeness or its alignment with the most recent product formulations or data. For any concerns or up-to-date information, we recommend visiting the manufacturer's website directly. The opinions and information provided here do not necessarily reflect the views of Supplement Warehouse; they represent the perspectives and information from the manufacturers and users. Furthermore, these statements have not been evaluated by the Food and Drug Administration. The products mentioned are not intended to diagnose, treat, cure, or prevent any disease or illness.

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