Reduced kidney function
* In severe cases, kidney failure
Health Conditions
Mayo Clinic specifically notes that vitamin D toxicity can lead to kidney stones and kidney trouble. ([Mayo Clinic][1])
How Much Vitamin D Is Too Much?
For most adults, the tolerable upper intake level is **4,000 IU (100 micrograms) per day** from all sources unless a healthcare professional recommends a higher dose for a specific reason. ([ODs][2])
That does not mean 4,001 IU is automatically toxic. Toxicity usually happens with much higher intake or inappropriate long-term supplementation.
