Quick answer
NIH says very high vitamin D levels can cause high blood calcium and kidney stones, and in one large trial calcium plus vitamin D went with 17% more stones. A meta-analysis of 48 trials found vitamin D raised blood and urine calcium but not kidney stones. Ask your doctor if you have had kidney stones.1,2,3
Key facts
- NIH says very high vitamin D levels, above 150 ng/mL (375 nmol/L), can cause high blood calcium, with symptoms that include kidney stones.1,2
- In the Women's Health Initiative, 36,282 women after menopause given 1,000 mg of calcium and 400 IU of vitamin D a day had 17% more kidney stones over 7 years.2
- A meta-analysis of 48 trials with 19,833 people found vitamin D raised blood calcium (risk ratio 1.54) and urine calcium (1.64) but not kidney stones (0.66, range 0.41 to 1.09).3
- A review of 22 trials at 3200 to 4000 IU a day for at least 6 months found more high blood calcium (risk ratio 2.21) but no significant difference in kidney stones.4
- In VITAL, 2,000 IU a day for about five years caused no more high blood calcium or kidney stones than placebo.5
What NIH says about vitamin D and kidney stones
NIH names kidney stones as one result of vitamin D toxicity. Because vitamin D increases calcium absorption in the gut, a toxic amount causes marked high blood calcium, which can lead to nausea, vomiting, muscle weakness, confusion, pain, dehydration, excessive thirst and urination, and kidney stones. NIH ties this to blood levels above about 150 ng/mL (375 nmol/L).1,2
Extremely high levels can cause kidney failure, calcium deposits in soft tissues, an irregular heartbeat and even death. Such cases almost always come from far too much vitamin D in supplements, including products made with manufacturing errors, taken wrongly or prescribed in error.1,2
NIH also reports that other, shorter trials of vitamin D alone or with calcium in adults, lasting 24 weeks to 5 years, found more high blood and urine calcium but not more kidney stones.2
The calcium plus vitamin D result
Taking calcium with vitamin D can raise the chance of kidney stones. In the Women's Health Initiative, 36,282 women after menopause given 1,000 mg of calcium and 400 IU of vitamin D a day had 17% more kidney stones over 7 years than those on placebo.2
The Women's Health Initiative gave about 2,100 mg a day of calcium from food and supplements together, with moderate vitamin D. NIH notes that taking calcium supplements in combination with vitamin D may raise the risk of certain side effects, and that most trials of vitamin D for bone also gave calcium, which makes the effect of each hard to separate.2
What larger reviews and trials found
| Source | What it found |
|---|---|
| Meta-analysis of 48 trials, 19,833 people, 24 weeks or longer | Blood calcium raised (risk ratio 1.54) and urine calcium raised (1.64); kidney stones, reported in 9 trials, not raised (0.66, range 0.41 to 1.09) |
| Review of 22 trials, 12,952 adults, 3200 to 4000 IU a day for 6 months or longer | Blood calcium raised (risk ratio 2.21); urine calcium and kidney stones not significantly different |
| VITAL, 25,871 adults, 2,000 IU a day for a median of 5.3 years | No more high blood calcium or kidney stones than placebo |
The authors of the 2016 meta-analysis said additional large trials are needed to confirm that vitamin D does not raise stone risk. The 2023 review noted that safety results were often incompletely reported and concluded that this dose range is not free of adverse effects, mainly high blood calcium.3,4
Side effects are uncommon at 2,000 IU a day. In VITAL, that amount taken for about five years caused no more high blood calcium, kidney stones or stomach complaints than placebo.5
Who should ask their doctor
Ask your doctor before taking vitamin D, or vitamin D with calcium, if you have had kidney stones, have high blood calcium or kidney disease, or take a thiazide diuretic, which can raise blood calcium when combined with vitamin D. Anyone with persistent symptoms such as great thirst, nausea or unusual muscle weakness while taking supplements should also ask.1,2
Questions people ask
Does vitamin D3 cause kidney stones?
NIH's statements cover vitamin D in general, and the meta-analysis of 48 trials covered both forms. Vitamin D raised blood and urine calcium in that review but not kidney stones.2,3
Does vitamin D with calcium cause kidney stones?
In the Women's Health Initiative, 1,000 mg of calcium with 400 IU of vitamin D went with 17% more kidney stones over 7 years. NIH says other shorter trials found no more stones. Ask your doctor.2
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Sources
- Office of Dietary Supplements, National Institutes of Health. Vitamin D: Fact Sheet for Consumers. Updated November 8, 2022. Opened 2026-10-07.
- National Institutes of Health, Office of Dietary Supplements. Vitamin D: Fact Sheet for Health Professionals. Updated June 27, 2025. Opened 2026-10-07.
- Malihi Z, Wu Z, Stewart AW, Lawes CM, Scragg R. Hypercalcemia, hypercalciuria, and kidney stones in long-term studies of vitamin D supplementation: a systematic review and meta-analysis. Am J Clin Nutr. 2016;104(4):1039-1051. Opened 2026-10-11.
- Zittermann A, Trummer C, Theiler-Schwetz V, Pilz S. Long-term supplementation with 3200 to 4000 IU of vitamin D daily and adverse events: a systematic review and meta-analysis of randomized controlled trials. Eur J Nutr. 2023;62(4):1833-1844. Opened 2026-10-11.
- Manson JE, et al. Vitamin D Supplements and Prevention of Cancer and Cardiovascular Disease. N Engl J Med. 2019;380(1):33-44. Opened 2026-10-01.
This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.