That headline is a little too strong: four symptoms alone cannot prove vitamin D toxicity. Too much vitamin D from supplements can raise calcium levels in the blood, causing a recognizable group of symptoms. ODS+1
4 warning signs of too much vitamin D
- Nausea or vomiting — especially when persistent or accompanied by poor appetite. ODS
- Excessive thirst and frequent urination — often related to elevated calcium levels and dehydration. ODS
- Muscle weakness or unusual fatigue — can occur with vitamin D toxicity. ODS
- Confusion or kidney problems — severe toxicity can lead to kidney stones, impaired kidney function, irregular heart rhythms, and, in extreme cases, kidney failure. ODS+1
How much is too much?
For most adults, the NIH lists 4,000 IU (100 mcg) per day as the tolerable upper intake level from all sources. That’s a safety limit, not necessarily the amount appropriate for everyone; doctors may temporarily prescribe higher doses to treat a documented deficiency. ODS
Vitamin D toxicity is usually caused by excessive supplementation, not sunlight. If you’re taking a high-dose supplement and develop several of these symptoms, speak with a healthcare professional rather than continuing to increase the dose on your own. ODS
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