Several decades of evidence have documented that dietary practices can prevent nutrient deficiency diseases, such as scurvy and rickets, and also play a role in the prevention other diseases, such as cardiovascular disease and osteoporosis. Because of these benefits, evidence on potential new relationships between nutrients and chronic disease is always in demand. However, gathering sufficient knowledge to draw conclusions about these relationships remains a challenge.

The Committee on Examination of the Evolving Science for Dietary Supplements was convened to look at the possibility that the scientific method could be accelerated to yield findings more quickly by identifying patterns of evolving evidence. For instance, can patterns of research evidence be observed in identified nutrient-disease relationships that can be applied to predict potential nutrient-disease relationships earlier in the research process and benefit the public by enabling earlier application of such knowledge?

Key findings from this report include:

• confidence in nutrient-disease relationships can change, often in unexpected direction;
• no pattern of evidence clearly predicts change in the confidence of relationships, particularly those initially deemed uncertain or promising;
• large randomized trials have the greatest impact in changing the level of confidence in a nutrient-disease relationship.