“All-Time High” Vitamin D Awareness May Make New DRI Less Relevant – CRN

Consumer enthusiasm for vitamin D is outpacing the research community and may make upping the dietary reference intake level less relevant to the supplement industry.

The Council for Responsible Nutrition's VP of Scientific and Regulatory Affairs Andrew Shao said establishing higher DRI values "may not matter" because vitamin D research overall has been "so positive" and "consistent" that it has fostered awareness.

The American Journal of Clinical Nutrition published a report Aug. 8 on a 2007 National Institutes of Health meeting "Vitamin D and Health in the 21st Century: an Update." At the meeting, experts discussed vitamin D research, benefits and future research needs - including a debate over whether to revisit the DRI or not.

Staff from NIH's Office of Dietary Supplements determined that more research is needed in certain areas before the Institute of Medicine could revisit and amend the current DRI (¹ (Also see "Vitamin D NIH Conference Experts Support Raising Upper Limit" - Pink Sheet, 10 Sep, 2007.), p. 3).

The private, non-governmental IoM established a DRI for vitamin D in 1997, which includes Adequate Intake (AI) levels and Tolerable Upper Intake Levels (UL), but IoM did not establish a Recommended Dietary Allowance (RDA) (see chart: " ² Current DRI Levels For Vitamin D ").

Cat Is Out Of The Bag

"What's happening now, irrespective of what IoM is doing or ODS for that matter, is that consumer awareness is being built so high that consumers are starting to select products that have been formulated with higher levels of vitamin D," said Shao.

He said the supplement industry has in turn supplied products with higher vitamin D levels.

Given current levels of awareness, Shao said, "I don't know that it really matters that IoM hasn't weighed in or won't weigh in terms of getting their DRI process started and coming to final recommendations."

"The cat is out of the bag" concerning research on vitamin D benefits, Shao said. As the science accumulates, experts are supporting higher intake levels, Shao said.

Shao pointed out vitamin D is especially hard to measure, as it is "confounded by our degree of sun exposure," it "appears relatively little in the food supply," and it is also difficult to determine a person's "vitamin D status" - whether they are "replete or deficient."

Shao said ODS is charged with evaluating the state of the research, identifying gaps and then looking to fill them.

Patsy Brannon, a professor of nutritional sciences at Cornell University and one of the authors of the "Overview" summary of the NIH meeting, said the meeting's findings "reflect the need for large, well-controlled, randomized, double-blind dose-response studies across the life reproductive stages."

While information is still needed in certain areas and specific intake levels may not yet be determinable, there is enough information there to make "general recommendations" to the public, Shao said.

Shao said ODS concluded more information is required to determine benefits of vitamin D on bone health for all age/gender groups, particularly children, younger men and infants; research already is adequate for older women.

During the meeting some experts stressed the lack of safety data on vitamin D precludes the development of new recommendations.

CRN disagrees, maintaining there are "ample data, at least for adults, available showing that vitamin D is safe up to very, very high intake levels, levels that would be much higher than would be needed for any kind of benefit," Shao said. Shao also said he thinks the industry has a good understanding of the optimal status needed for maintaining bone health.

NPA Predicts Eventual Vitamin D DRI Boost

The news surrounding vitamin D continues to be positive overall, according to Dan Fabricant, the Natural Products Association's VP of scientific and regulatory affairs. He said the industry is aware of the limited research and is working to fill the gaps.

Fabricant said the DRI "will most likely increase," and possibly within the next few years.

The numbers will be based on a lot of deliberation and consideration, however. "As the science evolves, those limits for something like vitamin D need to increase," he said. "It's just a matter of really being timely with the evaluation of science."

Higher levels of vitamin D are needed, Fabricant said, adding the benefits include "seeming to prevent degenerative disease."

Christine Stencel, a spokeswoman for the IoM, said the institute is in discussions now with "relevant federal agencies" about revisiting vitamin D -conducting a new review of the data and the "evidence of how much vitamin D and calcium people need for health."

Shao said once the research gaps are identified, ODS may look to partner with a center or institute and put out calls for grant proposals so research can be furthered.

- Katie Stevenson ([email protected])