Kidney stones are hard, crystalline masses that can form in your urinary tract and trigger extreme pain in your back, side or lower abdomen. The presence of certain types of kidney stones is related to your body's vitamin D status. However, these stones occur when your levels of this vitamin rise too high, not when they fall too low.
Kidney Stone Basics
Your urine contains waste material that comes from your body's internal processes. Normally, this material stays dissolved in your urine and passes from your body without incident. However, in people with kidney stones, these materials separate out from urine and form crystals, or stones, of various sizes. If a kidney stones is big enough, it can trigger pain by lodging in the urinary tract and blocking the normal urine flow. The material most commonly found in kidney stones is the mineral calcium, according to the National Kidney and Urologic Diseases Information Clearinghouse.
Vitamin D and Calcium
The vitamin D in your body affects your calcium status in two main ways. First, the presence of vitamin D encourages the passage of the calcium in your food from your intestinal tract to your bloodstream. Once calcium is in your bloodstream, vitamin D helps regulate its level of concentration, and thereby supports its proper use throughout your body. When your level of vitamin D intake rises, your blood levels of calcium rise as well. If you consume an excessive amount of vitamin D, the subsequent rise in your calcium levels can trigger harmful changes in your soft tissues, bones and kidneys.
Stone Formation
The excessive presence of vitamin D in your body is called vitamin D toxicity, or hypervitaminosis D. In addition to causing abnormal increases in your blood calcium levels, this disorder can abnormally elevate the amount of calcium in your urine and trigger a condition known as hypercalciuria, which is normally inherited. In people with hypercalciuria, the high level of calcium in the urine leads to the formation of kidney stones that contain calcium, as well as one of two other types of waste material called oxalate and phosphate. These stones can form within the kidneys themselves or further down the urinary tract.
Considerations
Hypervitaminosis D rarely occurs, even in people who take vitamin D supplements, MayoClinic.com reports. However, certain factors can increase your risks for developing the disorder, including pre-existing kidney or liver problems and the use of medications called thiazide diuretics. If you develop hypervitaminosis, treatment options include halting your use of vitamin D supplements, strictly limiting your calcium intake and taking certain prescribed medications. Some people with severe forms of the disorder require treatment in a hospital setting. Preadolescents, teens and adults have a maximum safe daily vitamin D intake of 100 mcg, according to the Office of Dietary Supplements. Consult your doctor for more information on vitamin D intake, hypervitaminosis D and kidney stone formation.
References
- National Kidney and Urologic Diseases Information Clearinghouse: Kidney Stones in Adults; October 2007
- MedlinePlus: Hypervitaminosis D
- Office of Dietary Supplements - National Institutes of Health: Dietary Supplement Fact Sheet; Vitamin D
- MayoClinic.com; Vitamin D Toxicity; What If You Get Too Much?; Katherine Zeratsky, R.D., L.D.; December 2010
