Yes. Too much vitamin D can be harmful, but toxicity usually comes from taking high-dose supplements for a prolonged period, not from sunlight or ordinary foods.
What happens with too much vitamin D?
Excess vitamin D can cause hypercalcemia—too much calcium in the blood. Symptoms can include:
- Nausea, vomiting, or poor appetite
- Constipation
- Excessive thirst and frequent urination
- Weakness or fatigue
- Confusion
- Kidney stones or kidney damage
For most adults, the usual recommended intake is around 600–800 IU (15–20 mcg) per day, depending on age and circumstances. The U.S. tolerable upper intake level for adults is 4,000 IU (100 mcg) per day from supplements and food, although doctors may temporarily prescribe higher doses to treat a documented deficiency.
Don’t routinely take high-dose vitamin D without medical guidance. If you’re taking vitamin D and want to know whether your dose is appropriate, tell me the IU/mcg amount you’re taking, how often, and your age, and I can put it in context.
