Calcium stones are the most common type of kidney stone. Consuming more calcium, however, doesn’t cause them. In fact, a calcium-rich diet may help prevent kidney stones.
You might not know you have a kidney stone until it passes into your ureter—the tube connecting the kidney and bladder. At that point, the stone can cause intense pain in the side, back, lower abdomen or groin.
A new study has lent support to the notion that more calcium in a diet may lower the risk of getting kidney stones.
Eric Taylor, MD, at Brigham and Women's Hospital in Boston and medical director of the Maine Medical Partners Kidney Stone Prevention Program in Portland, led an investigation evaluating 5,270 kidney stone cases and patient dietary habits.
The scientists found that patients who consumed the most dietary calcium from foods had about 20 percent lower risk of developing kidney stones than those who consumed the least calcium.
As Dr. Taylor highlighted, individuals who were getting their calcium from sources other than milk and other dairy products were also lowering their kidney stone risk.
Sardines, spinach, kale, fortified orange juice, soybeans and enriched breads are all top dietary sources of calcium.
Dr. Taylor told dailyRx News, “I encourage my kidney stone patients to consume enough dietary calcium to optimize bone health—ideally between three to four servings per day. Our study provides additional evidence that restriction of dietary calcium has no role in the prevention of kidney stones.”
The authors also pointed out that their results did not provide insight as to why dietary calcium may have different effects on kidney stone risk than supplemental calcium. Supplemental calcium use has been associated with a nominal increase in kidney stone formation, according to this paper.
“For example, participants in the Women’s Health Initiative (WHI) taking 1,000 mg of supplemental calcium and 400 IU of vitamin D3 daily were 17 percent more likely to have a kidney stone than participants in the placebo group,” wrote the authors.
Deborah Gordon, an integrative physician at Madrona Homeopathy in Ashland, Oregon, told dailyRx News, “I think calcium supplementation has been overly stressed and that it may cause more harm than good. Individuals should let their food provide all the calcium they need.”
The study was published online in March in The Journal of Urology and will be published in the actual journal in October.