Although the new Dietary Reference Intake (DRI) values for Vitamin D will apply to both Canada and United States, there appears to be some disagreement among the experts when setting these values. The Institute of Medicine (IOM) in December 2010, revised the DRI’s for Vitamin D intake. This was not without much discussion , some of it in support for providing evidence-based deliberations and others being critical of the way in which this evidence, in particular the new roles of Vitamin D were being dismissed. Anyone who has followed the changes in how we view this Vitamin and the increasing recommendations for higher and higer DRI values, can attest to the growing debate among various expert groups.
The newest DRI levels for Vitamin D are based solely on bone health indicators . As a result, the Recommended Daily Allowance (RDA) for infants is 400IU, for everyone else; the RDA is 600IU which covers ages 1 to 70 years of age. Those over 70, have an RDA of 800IU. These are dietary recommendations and are based on the assumption that there is minimal sun exposure and were set to achieve 50nmol/L of plasma 25-hydroxyvitamin D. New Upper Levels for Vitamin D are 4,000 IU for ages 9 years and over, with lower levels set for younger ages.
However, there is a need for more research to determine non-skeletal benefits of Vitamin D, and whether different intake levels are needed to satisfy those actions. Why? In the past years, we have growing evidence that a focus on Vitamin D’s role in bone metabolism is potentially missing a host of other functions within the normal human physiology.
For now at least, we have updated RDA’s that update the previous levels which were set in 1997 especially since recent national surveys produced evidence that Vitamin D status was poor, especially in certain subpopulations in both Canada and the United States. This alone suggested that the RDA levels needed to be much higher than previous established.
Expect to see more information about Vitamin D’s influence on health outcomes based on additional randomized controlled trials.
[Pfizer, Consumer nutrition and health report; Volume 20, Number 4; December 2011]