Should people with kidney stones take vitamin D?
Recently, Dr Jie Tang and colleagues from the University of Colorado School of Medicine attempted to answer that question by studying more than 16,000 people, about 700 of whom had kidney stones. The authors wanted to see if vitamin D blood levels were related to kidney stones.
Tang J, McFann KK, Chonchol MB. Association between serum 25-hydroxyvitamin D and nephrolithiasis: the National Health and Nutrition Examination Survey III, 1988-94. Nephrol Dial Transplant. 2012 Dec;27(12):4385-9
The question of whether or not to supplement patients with kidney stones is a common and important question. As Dr. Tang wrote,
“At this time, there is no consensus in the management of nutritional vitamin D supplementation in patients with kidney stone disease. In clinical practice, physicians often withhold calcium and vitamin D supplementation in stone formers.”
The authors added,
“However, this practice has become a health-care challenge because of the overwhelming epidemiological evidence of health benefits from nutritional vitamin D supplementation in the general population. It is especially problematic with regard to bone health, as reduced bone mineral density is more prevalent in patients with kidney stone disease, and nutritional vitamin D supplementation is important in maintaining a dynamic calcium and bone balance.”
The authors looked for any association of vitamin D levels to kidney stones in the NHANES III group of patients. They found no relationship between vitamin D blood levels and kidney stones. Even when they used a cutoff of 50 ng/ml, they found no association between 25(OH)D and kidney stones.
The sad thing is that the prevention of kidney stone is easy; just alkalize the body by increasing the magnesium and potassium in the diet. The best way to do this is to eat foods rich in potassium and magnesium such as vegetables, fruit, seeds and nuts. In fact, over three years, those on a potassium-magnesium citrate preparation had a five-fold reduction in kidney 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.
It is important that the salt preparation be an alkalizing one like citrate. The problem is that such a preparation cannot be patented, so doctors treating kidney stone patients know little or nothing about it.
The present study implies that if you have kidney stones, your risk of recurrent kidney stones will not be affected by whether or not you take vitamin D. However, you can reduce the risk dramatically by keeping hydrated and by alkalizing your body, and the best way to do that is by a diet rich in magnesium and potassium containing foods.