“Too much salt could mean too little calcium, say researchers.” This headline yesterday, caught my attention—partly because I have learned that when researchers focus on calcium, they tend to ignore other minerals and cofactors: magnesium in particular and, to a lesser extent, vitamin D.
The study, conducted by University of Alberta, Canada researchers and published in the American Journal of Physiology’s Renal Physiology, was done on mice that lacked the gene to code for the molecule (NHE3) responsible for sodium absorption in the body, and which the researchers now believe also plays a role in regulating calcium levels.
In plain English, when the body tries to get rid of sodium, it gets rid of calcium at the same time, the researchers concluded. This, they warned, could raise the risks not only of kidney stones, but also of osteoporosis.
Not so simple, according to Natural Vitality’s President, Ken Whitman, and Carolyn Dean, ND, author of The Miracle of Magnesium, my go-to sources for all things magnesium, and a more holistic view of minerals’ role in the body.
What about magnesium?
“If researchers found that high dietary sodium caused both sodium and calcium to show up in the urine, I would ask if they looked for any other minerals in the urine,” said Dean. Too much table salt depletes magnesium even more than calcium, she explained. The researchers’ warning that high calcium levels in urine leads to kidney stones indicates magnesium deficiency as well, because “magnesium treats kidney stones and people who are deficient in magnesium develop kidney stones.”
Dean also noted that there are important differences between table salt and sea salt: "Sea salt has 72 minerals all in perfect proportions, not just sodium and chloride, like table salt. So what people are saying is salt is not true salt, and then they are drawing all kinds of erroneous conclusions."
Bigger picture, better studies
“I think that sometimes focusing in too tightly on things one can lose the bigger picture of the system of which the 'things’ are a part," Whitman said. "Proving that point, these researchers missed magnesium."
The bigger issues, he said, are calcium absorption and vitamin D activation (from its storage form to the active form). For both processes, the body needs adequate magnesium levels.
The other serious issue, said Whitman: too much unabsorbed calcium. "Decades of high-calcium diets and calcium supplementation haven't yet relegated osteoporosis or osteoporotic fractures to minor footnote status only affecting a few! [In fact, rates have grown significantly.] These researchers are still beating the drum on inadequate levels of calcium in the body leading to osteoporosis."
Whitman also questioned the assumption that the problem is that we're using too much salt. "If it were as simple as that, we wouldn't have unabsorbed calcium building up in soft tissues and causing hardening of the arteries, a leading cause of death. Excess would simply be eliminated in the urine," he said.
What's more, recent research indicates that eating less salt may not be a one-size-fits-all recommendation for health. To learn more, read this New York Times article.
Study findings can help expand our knowledge of how the body works, but it's a good idea not to draw any final conclusions, Whitman said. "There's a danger in trying to simplify an understanding of a complex system—the human body—into a headline. In the absence of a real understanding this can lead to simplistic thinking like 'take more calcium’ and 'eat less salt.’ These can then become prevailing wisdom, which prevents observation and rejects input, however valid, that doesn't conform."
Are you concerned about sodium intake? What about magnesium deficiency? Please share your thoughts in the comments below.