Calcium and vitamin D are two essential nutrients long known for their role in bone health. But since 2000, the public has heard conflicting messages about other benefits of these nutrients—especially vitamin D—and also about how much calcium and vitamin D they need to be healthy. To help clarify this issue, the United States and Canadian governments asked the IOM to assess the current data on health outcomes associated with calcium and vitamin D, as well as updating the nutrient reference values, known as Dietary Reference Intakes (DRIs).
In this report, the IOM proposes new reference values that are based on much more information and higher-quality studies than were available when the values for these nutrients were first set in 1997. The IOM finds that the evidence supports a role for vitamin D and calcium in bone health but not in other health conditions. Further, emerging evidence indicates that too much of these nutrients may be harmful, challenging the concept that “more is better.”