Vitamin D Deficiency: MedlinePlus
medlineplus.gov › vitaminddeficiencyMar 24, 2023 · Getting too much vitamin D (known as vitamin D toxicity) can be harmful. Signs of toxicity include nausea and vomiting, poor appetite, constipation, weakness, and weight loss. Very high levels of vitamin D can damage the kidneys. It also raises the level of calcium in your blood.