The four warning signs to watch for are:
1. **Nausea, vomiting, or loss of appetite**
2. **Unusual weakness or fatigue**
3. **Excessive thirst and frequent urination**
4. **Kidney stones or kidney problems**
The key message is not “stop vitamin D immediately.” It is: **do not take more than you need, and if you are using high-dose supplements or develop concerning symptoms, get medical advice and appropriate blood testing.**
