Of the many groups of patients with kidney stones, one of the largest groups has normocalcemic hyperparathyroidism or NHPT. They have normal serum calcium, elevated parathyroid hormone, mostly calcium oxalate kidney stones, a family history of kidney stones, and they tend to be obese.
Recently, Dr. Chrysoula Pipili and colleagues at the University of Toronto did something no one else had ever done: they measured the vitamin D levels of the patients with NHPT. These stone formers’ 25(OH)D levels were low, not high, with 55% having 25(OH)D levels lower than 20 ng/ml, while controls (stone formers without NHPT) had significantly higher 25(OH)D levels, about 27 ng/ml. However, the NHPT patients still had elevated parathyroid hormone, putting them at risk for kidney stones.
What did the good doctors do? They treated several of these stone forming patients with 1,000 IU/day of vitamin D, which significantly decreased their parathyroid hormone levels, without increasing their urinary calcium, leading the authors to wonder if additional doses of vitamin D would have cured their NHPT.
The authors concluded, “The correction of vitamin D deficiency with oral vitamin D supplements may assist in management of stone formers with NHPT.” They added, “Prospective studies are warranted on whether vitamin D supplementations should be considered as a therapeutic goal in stone formers with (in) sufficient vitamin D status.”
How times change. Just a few months ago, the myth that vitamin D causes kidney stones was replaced by a scientific study showing that treating vitamin D deficiency in stone formers did not increase the risk of stone formation. And now, we have a call for a trial of giving vitamin D deficient NHPT stone formers vitamin D to see if it reduces their kidney stones.
I have written about kidney stones before: chronic acidosis combined with lack of potassium and magnesium in your diet is the most common cause of kidney stones. This line of thinking is based on, among other things, a positive double blind study on the use of potassium and magnesium in prevention of stones.
Ettinger B, Pak CY, Citron JT, Thomas C, Adams-Huet B, Vangessel A. Potassium-magnesium citrate is an effective prophylaxis against recurrent calcium oxalate nephrolithiasis. J Urol. 1997 Dec;158(6):2069-73.
The typical American diet, not vitamin D, is to blame for many cases of kidney stones, together with the lack of two minerals in diet (magnesium and potassium) and the lack of adequate fluid intake. If you have ever had a kidney stone, drink eight glasses of water per day and eat lots of vegetables, fruits, seeds, and nuts. If you just can’t do that, consider supplementing with potassium and magnesium.