Altered mental status
Vitamin D toxicity can cause symptoms like agitation, confusion, and unresponsiveness. This vitamin D side effect also appears to result from elevated calcium levels caused by high doses of vitamin D.
Having Hypercalcemia can lead to a changed mental status in people with vitamin D toxicity. People with this toxicity can also commonly have symptoms like depression, confusion, and psychosis. In very extreme cases, coma has also been reported.
In a case report performed a few years ago, a man in his sixties accidentally took 200,000 IU of vitamin D daily because he misinterpreted medication instructions. He showed altered mental status and a few other severe symptoms related to hypercalcemia.
He was in a constant state of agitation and confusion for the first ten days of his stay in the hospital. Fortunately, his symptoms of this vitamin D side effect gradually improved as his calcium levels decreased.
It took about 18 days for his calcium levels to return to optimal levels.
