Background

Vitamin D is a unique nutrient because its needs can be met in two distinct ways: by endogenous production from sun exposure, or from foods and dietary supplements. In addition to calcium metabolism, accumulating evidence indicates other roles in human health, including immune function, reduction of inflammation, and effects on cell proliferation, differentiation, and programmed cell death. Even as its importance to health expands, concerns about the sufficiency of vitamin D in the population are growing. Reports of rickets (the classic vitamin-D deficiency disease) and low blood levels of the biomarker of vitamin D status—25(OH)D—among various subgroups of the U.S. population raise concerns about current public health approaches to ensure vitamin D adequacy.

The first NIH conference on Vitamin D and Health in the 21st Century was held in 2003. Subtitled Bone and Beyond, it considered knowledge regarding the measurement and maintenance of vitamin D status and the development of programs to reduce the prevalence of insufficiency. It also identified research needs, including the following:

• Better definitions of vitamin D status with meaningful cutoff values and biomarkers that have functional relevance and validated assessment methods
• Dose-response relationships between sunlight exposure and endogenous vitamin D synthesis with specific health outcomes in various racial/ethnic groups
• Investigations of genetic polymorphisms to identify tissue-specific roles of vitamin D
• Exploration of the relationships of obesity and weight loss on vitamin D status
• Improved methods for assessing vitamin D intakes, particularly from fortified foods and supplements
• Biomarkers and functional outcomes for bone and non-bone tissue that reflect vitamin D status
• A systematic evidence-based review to determine the current state of knowledge

Progress has been made in addressing many of these research needs. Yet, since the 2003 conference, new issues have been raised. For example, reports indicate a growing prevalence of vitamin D insufficiency/deficiency in the U.S. population. They also suggest that vitamin D inadequacy occurs at blood levels previously viewed as adequate. It is time to assess current knowledge of the efficacy and safety of vitamin D to identify new research needs that will help ensure optimal vitamin D status across the life cycle. For this reason, the National Institutes of Health (NIH) Office of Dietary Supplements (ODS) will convene a conference on Vitamin D and Health in the 21st Century—An Update September 5–6, 2007, in Bethesda, Maryland. The goals of the conference are as follows:

• Evaluation of the efficacy and safety of vitamin D across the life cycle considering the evidence-based review produced through the Agency for Healthcare Research and Quality (AHRQ) Evidence-based Practice Center Program, and research and related tools that have become available since the 2003 NIH conference, Vitamin D and Health in the 21st Century—Bone and Beyond
• Presentation of current data/research on vitamin D status, sources of vitamin D, and functional outcomes across the life cycle
• Identification of knowledge gaps, methodological challenges, and research needs on vitamin D production, activation, metabolism, and status assessment across the life cycle

The 2-day conference will open with a review of vitamin D production, bioavailability, metabolism, active forms, functions, and metabolic turnover. Vitamin D’s effects on health outcomes across the life cycle and measurement of status will also be critically evaluated. Other topics to be addressed include the impact of dietary intakes and sun exposure on blood levels of 25(OH)D and its relationship to vitamin D status.

At the conference, invited experts will present information pertinent to these topics and goals. The findings of the AHRQ evidence-based review on vitamin D will also be presented. Each of the four sessions will include a panel of the presenters who will address questions relevant to the session topic and suggest future research needs. Attendees will have opportunities to engage in discussions with the panels. Each panel’s summary presentation will become part of the conference record and be used by organizers to compile conference proceedings and to inform NIH’s research agenda.

This conference will be of interest to scientists and health professionals with a background and/or interest in vitamin D.

Continuing Professional Education
Continuing Professional Education Credits will be awarded for the conference by the Commission on Dietetic Registration. The Vitamin D Conference as been approved for a maximum of 14 credits at CPEU Level 2.