View source for Translations:Vitamin D/76/en

== Excess ==
{{further|hypervitaminosis D}}
Vitamin D toxicity is rare. It is caused by supplementing with high doses of vitamin D rather than sunlight. The threshold for vitamin D toxicity has not been established; however, according to some research, the tolerable upper intake level (UL) is 4,000 [[International unit|IU]]/day for ages 9–71 (100{{nbsp}}μg/day), while other research concludes that, in healthy adults, sustained intake of more than 50,000{{nbsp}}IU/day (1250{{nbsp}}μg) can produce overt [[toxicity]] after several months and can increase serum 25-hydroxyvitamin D levels to 150{{nbsp}}ng/mL and greater. Those with certain medical conditions, such as primary [[hyperparathyroidism]], are far more sensitive to vitamin D and develop [[hypercalcemia]] in response to any increase in vitamin D nutrition, while maternal hypercalcemia during pregnancy may increase fetal sensitivity to effects of vitamin D and lead to a syndrome of intellectual disability and facial deformities.