Vitamin D -- a general term for a family of related hormones -- makes up an important part of your diet. Consuming vitamin D helps to maintain healthy bones and teeth, and also helps to maintain a proper parathyroid hormone balance within your body. However, excess vitamin D consumption can harm your health, increasing your risk of kidney stones.
Toxic Vitamin D Intake
Excess vitamin D intake can eventually lead to hypervitaminosis D, or vitamin D toxicity. In general, consuming up to 10,000 IU of vitamin proves safe for many healthy adults, though the upper tolerable limit -- the amount of the vitamin considered safe for most individuals -- is 4,000 IU, according to the Linus Pauling Institute. Consuming doses significantly higher than the upper tolerable limit can eventually lead to vitamin D toxicity, and might lead to kidney stones.
Effect on Kidney Stone Development
Vitamin D toxicity can promote kidney stone development due to the hormone's effect on calcium. The activation of vitamin D within your body signals for calcium to enter your bloodstream, increasing your blood calcium concentration. This excess calcium level continually flows through the blood filtering units within your kidney, and can eventually form deposits within your kidney tubules. Over time, these deposits grow into kidney stones.
Identifying Kidney Stones
Smaller kidney stones often pass through your kidneys and into your urine without causing any noticeable symptoms, but large kidney stones can cause discomfort. Depending on the location of the stone within your urinary tract, you might feel pain in your lower abdomen, groin, buttocks or lower back. The stone can also harm the tissue that lines your urinary tract, causing blood to seep into your urine, or cause nausea and vomiting. Very large stones could also completely disrupt the flow of urine through into your bladder and prove extremely painful.
Prevention and Treatment
You can help to prevent kidney stones by maintaining a vitamin D intake well below the upper tolerable limit. If you take very large doses of vitamins, or combine vitamin supplements, you must consult a medical professional to help prevent excess vitamin D consumption. If you develop kidney stones due to excess vitamin D, you can often treat the condition by simply allowing the stone to pass, though some stones require surgical removal.
