This site is intended for healthcare professionals
Login | Register (NOW FREE)

Medical search

vitamin D excess

FREE subscriptions for doctors and students... click here
You have 3 open access pages.

Excessive vitamin D may be the result of:

  • excessive intake:
    • self-medication, for example in women concerned about osteoporosis, supplementation during pregnancy (see notes)
    • iatrogenic
  • increased production of calcitriol:
    • high 1-alpha-hydroxylase in kidney, for example in hyperparathyroidism
    • extra-renal production of calcitriol - 1-alpha-hydroxylase activity in granuloma cells, for example in sarcoidosis, sarcomas, some lymphomas

The features of vitamin D excess are those of hypercalcaemia due to increased bone resorption

  • early symptoms of toxicity include symptoms of hypercalcaemia such as thirst, polyuria and constipation
    • vitamin D toxicity can result in renal failure, which can rapidly become irreversible
    • if vitamin D toxicity secondary to excessive supplementation is suspected then vitamin D must be withdrawn and serum calcium and renal function checked urgently, since emergency inpatient care with rehydration is usually indicated (1)

Notes (2):

  • the Food Standards Agency states that taking 25µg (1,000 IU) of vitamin D supplements daily is unlikely to cause any harm in the general population
  • pregnancy
    • excess vitamin D in animals has been shown to have teratogenic effects. High systemic doses of vitamin D should be avoided during pregnancy
      • in consideration of all these factors in mind, the currently recommended dose for supplementation during pregnancy and breast-feeding (10µg [400 IU] daily) seems reasonable


  1. Drug and Therapeutics Bulletin 2006;44 (4):25-9.
  2. Drug and Therapeutics Bulletin 2006; 44(2):12-16.


The information provided herein should not be used for diagnosis or treatment of any medical condition. A licensed medical practitioner should be consulted for diagnosis and treatment of any and all medical conditions. Copyright 2016 Oxbridge Solutions Ltd®. Any distribution or duplication of the information contained herein is strictly prohibited. Oxbridge Solutions Ltd® receives funding from advertising but maintains editorial independence. GPnotebook stores small data files on your computer called cookies so that we can recognise you and provide you with the best service. If you do not want to receive cookies please do not use GPnotebook.