Why and How Synthetic Calcium Causes Constipation but Dietary Calcium Doesn’t

Many of our customers come to us after trying so many types of calcium, but struggling with the common side effects of constipation and other GI issues.  They’re struggling with the side effects from the very calcium supplements recommended for their health. If you’ve ever experienced bloating or constipation from calcium pills, the form of calcium may be to blame.

The most common calcium ingredient in supplements is calcium carbonate, a compound derived from limestone. While inexpensive and concentrated, calcium carbonate has low solubility and low bioavailability.  Much of it isn’t absorbed and remains in the digestive tract, where it can bind with fats and bile acids to form insoluble compounds. In fact, studies show that calcium carbonate reduces stool water content and slows everything down in your gut. 

A recent study finding that dietary calcium - like that in Seen’s calcium chew - actually decreases rates of constipation. A really different mechanism than the constipating effects of calcium carbonate.

But, thankfully, calcium from food behaves differently in the body. A 2024 population-based study published in Frontiers in Nutrition found that higher dietary calcium intake was associated with a significantly lower risk of constipation, especially in people with metabolic syndrome and postmenopausal women. Yes, the exact opposite of calcium carbonate!  Dietary calcium intake actually helped people who had already struggled with regularity.  The researchers used data from over 4,800 participants in the U.S. NHANES dataset. Individuals in the highest quartile of dietary calcium intake had a 72 percent lower risk of constipation compared to those in the lowest quartile (Zhu et al., 2024).

Why does dietary calcium make such a difference?

Calcium from real food like Seen chews is absorbed more efficiently and tends to come paired with nutrients that promote digestive regularity. Our chews and other calcium-rich foods contain magnesium, fiber, phosphorus that support gut motility and help maintain stool moisture. Additionally, dietary calcium may help regulate inflammation and gut microbiota, further supporting healthy bowel function in people with underlying metabolic conditions.

That’s right — increased dietary calcium intake is associated with a decreased risk of constipation.

We started Seen Nutrition with that exact perspective.  Our Calcium Chew Complete is made from milk minerals, organic dates, almonds, and Vitamin D mushrooms. There are no artificial sweeteners, sugar alcohols, or synthetic binders, only real food your body can recognize and digest. Our food-first philosophy shaped our chew and the whole foundation of our company.

If you’ve experienced constipation from calcium pills, the science now confirms what many of our customers have told us all along: calcium is important, but how you get it matters. We believe that our real-food chew actually supports - not harms - digestion and absorption and so you don’t have to choose between comfort and bone health.