High-Sodium Diets May Deplete Calcium

ALBERTAResearchers recently discovered an important link between sodium and calcium that may reveal why people who eat high-salt diets are prone to developing kidney stones and osteoporosis. The findings, published in the American Journal of Physiology-Renal Physiology, suggest when sodium leaves a body, it takes calcium along with it, creating risk for disease.

Researchers at the University of Alberta discovered sodium and calcium both appear to be regulated by the same molecule in the body. When sodium intake becomes too high, the body gets rid of sodium via the urine, taking calcium with it, which depletes calcium stores in the body. High levels of calcium in the urine lead to the development of kidney stones, while inadequate levels of calcium in the body lead to thin bones and osteoporosis.

"When the body tries to get rid of sodium via the urine, our findings suggest the body also gets rid of calcium at the same time," said lead researcher Todd Alexander, a Faculty of Medicine & Dentistry. "This is significant because we are eating more and more sodium in our diets, which means our bodies are getting rid of more and more calcium. Our findings reinforce why it is important to have a low-sodium diet and why it is important to have lower sodium levels in processed foods."

The researchers found a molecule that seems to have two jobsregulating the levels of both calcium and sodium in the body. The team worked with lab models that didn't have this important molecule, so the models' urine contained high levels of calcium. Because calcium was not absorbed and retained by the body, bones became thin.

The researchers concluded their findings provide very real biological evidence that this relationship between sodium and calcium is real and linked.