Nearly one in five U.S. adults are taking supplemental vitamin D, and a growing number are taking excessively high doses linked to an increased risk of fractures, falls, kidney stones and certain cancers, a new study suggests.
Vitamin D helps the body use calcium to support bone health. The recommended daily intake of vitamin D for most adults is 600 IU (international units), or 800 IU after age 70.
For the study, researchers examined nationally representative survey data collected for 39,243 adults from 1999 to 2014 to see how many people took daily doses of more than 1,000 IU and how many were taking more than 4,000 IU, which is the maximum recommended amount to avoid dangerous side effects.
High doses may be associated with an elevated risk of prostate and pancreatic cancers.
