Did you just buy another garbage can-sized bucket of vitamin D? Maybe Costco will take it back. Okay, maybe not. The Institute of Medicine (IOM) has released recommendations for how much vitamin D adults need every day, and the results might make your rethink your daily supplement use.
The IOM report proposes a recommended dietary allowance (RDA) for vitamin D of 600 international units (IU) per day for most healthy adults. The RDA increases to 800 IU per day for adults over the age of 70. But the daily intake should not exceed 4,000 IU for adults.
You might have more than enough vitamins now as a result of your taking fewer of them, but there is good news. The majority of Americans have sufficient levels of vitamin D already in their diets, with the possible exception of people who might have lower vitamin D levels due to diet or extremely limited sun exposure.