The amount of calcium your body absorbs might depend, in part, on the amount of dietary fiber you consume.
Researchers at UT Southwestern Medical Center report that patients with noninsulin-dependent diabetes (type 2) excreted less calcium through their urine when they consumed 50 grams of fiber a day than when they ate 24 grams a day. Excreting less calcium indicates that they absorbed less of the mineral.
"We already know that fiber helps improve your cholesterol and glucose control and improves your bowel regularity. Our new findings suggest that dietary fiber reduces the body's capacity to absorb calcium," said Dr. Abhimanyu Garg, professor of internal medicine and an investigator in the Center for Human Nutrition at UT Southwestern. He is senior author of a study appearing online in Diabetes Care. "Because more calcium equals better bone health, we recommend that people on high-fiber diets talk to their physician about increasing their dietary calcium as well, in order to get the most benefit from both."
Dr. Garg said it's important to speak with a physician or a registered dietitian before increasing your calcium intake because excessive levels may cause kidney stones.
The American Diabetes Association (ADA) recommends a daily intake of 24 grams of dietary fiber, but the average American consumes about 14 to 15 grams of fiber a day.
Sometimes called "roughage," dietary fiber is the indigestible portion of plant foods that pushes food through the digestive system, absorbing water and easing defecation. Calcium is a nutrient found in food that is absorbed by the body and then excreted in urine, feces or sweat. It is the most abundant mineral in the human body.
Prior research at UT Southwestern has shown that a high intake of dietary fiber, mostly from fruits and vegetables, lowers blood glucose levels and leads to decreased insulin levels in the blood, as well as lowering blood lipid concentrations in patients with type 2 diabetes, the most prevalent type of diabetes.
For the current study, 13 patients with type 2 diabetes ate either a high-fiber diet (50 grams per day) or the moderate-fiber diet (24 grams per day) recommended by the ADA for six weeks, then switched to the other diet for six weeks. All participants stayed at UT Southwestern's Clinical and Translational Research Center (CTRC) for the final week of each six-week period.