Does Intake of Vitamin D, Above Current Reference Intakes, Lead to Toxicity?
Twenty-two randomized trials provided data on toxicity outcomes although no trials reported data on soft tissue calcification. Twenty-one of the trials used doses of vitamin D above current reference intakes. Most of the trials were conducted in older adult populations and used vitamin D3 preparations. Twelve trials had scores ≥ 3 on the Jadad scale. One trial in infants with 600,000 IU vitamin D3 (one dose) reported an increased risk of hypercalcemia. Most trials were small, of short duration and inadequately powered to assess adverse events. Overall, vitamin D above current reference intakes was generally well tolerated. There was a non-significant increase in the risk of hypercalcemia and hypercalciuria with vitamin D relative to placebo, and these events did not appear clinically significant. We were unable to determine if there were differences between vitamin D2 and D3. The only significantly increased adverse event identified was an increase in renal stones in the large seven ye
