Yes. Too much vitamin D can be harmful, mainly because excessive vitamin D raises calcium levels in the blood (hypercalcemia). This usually happens from taking excessive supplements rather than from ordinary sun exposure.
4 warning signs of too much vitamin D
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Nausea, vomiting, or loss of appetite — Elevated calcium can upset the digestive system.
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Excessive thirst and frequent urination — High calcium can affect the kidneys and cause increased thirst and urination.
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Weakness, fatigue, or confusion — Significant hypercalcemia can cause pronounced tiredness, muscle weakness, and mental changes.
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Kidney problems or kidney stones — Excess calcium can contribute to kidney stones and, in severe cases, impaired kidney function.
How much is too much?
For most adults, the tolerable upper intake level is 4,000 IU (100 micrograms) of vitamin D per day from supplements and food unless a healthcare professional is deliberately using a higher dose for a documented deficiency. Some people are prescribed higher doses temporarily, so the upper limit isn’t a target dose.
If you’re taking a high-dose vitamin D supplement, particularly for months, ask your clinician whether you need 25-hydroxyvitamin D and calcium testing. Don’t discontinue a medically prescribed regimen without discussing it with your healthcare professional.
