Lifespan's A - Z Health Information Library

Hypervitaminosis D symptoms appear several months after excessive doses of vitamin D are administered.

An excess of vitamin D causes abnormally high blood concentrations of calcium, which can eventually cause severe damage to the bones, soft tissues, and kidneys. It is almost always associated with forms of vitamin D that require a doctor's prescription.

• Dehydration 
• Vomiting 
• Decreased appetite (anorexia)
• Irritability 
• Constipation 
• Fatigue

• Polydipsia (excessive thirst)
• Polyuria (passing large amounts of urine)
• Hypertension (high blood pressure)
• Hypercalcemia (excess calcium in the blood)
• Hypercalciuria (excess calcium in the urine)

Tests to confirm the diagnosis:

• Calcium - serum
• Phosphorus - serum 
• 25-hydroxyVitamin D levels
• 1,25 dihydroxyVitamin D levels
• X-ray of the bone (focusing on the long bones)

Stop taking vitamin D. Consult your physician. In severe cases, other treatment may be necessary.

Recovery is expected.

• Kidney damage
• Kidney stones

Call your health care provider if you or your child shows symptoms of hypervitaminosis D, and you have been taking vitamin D in excess of the recommended daily allowance. Also call if you or your child show symptoms and you have been taking a prescription form of vitamin D.

To prevent this condition, pay careful attention to the correct vitamin D dose.