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Recommended Vitamin D Levels Too Low

International Meeting of Vitamin D Scientists Reveals Most Not Getting Enough to Maintain Health

Consensus from the 13th Vitamin D Workshop seeks to increase upper limits of daily nutrient intake to maintain bone and tooth health for most of the globe’s inhabitants.

(April 24, 2006)

Vitamin D Receptor

Vitamin D Receptor

RIVERSIDE, Calif. — — Scientists and nutrition experts at the 13th Vitamin D Workshop agree that about half of the elderly in North America and two-thirds of the rest of the world are not getting enough vitamin D to maintain healthy bone density, lower their risks for fractures and colorectal cancer, improve walking speed in the elderly, and improve tooth attachment.

The conclusion of the 334 scientists from 23 countries at the meeting in Victoria, British Columbia April 8-12, was that, although the problem of insufficient vitamin D is widely recognized and reported, the usual advice to eat foods that contain vitamin D does not solve the problem for most adults. This “sunshine vitamin” is the one nutrient that foods alone cannot provide enough of. Most of our dietary vitamin D is added to foods by manufacturers. The workshop, organized by Anthony Norman, distinguished professor of biochemistry and biomedical sciences at UCR, covers the latest advances in vitamin D research over the past three years.

A wide variety of topics was covered at the meeting concerning the parent vitamin D3 (an essential nutritional substance) and its steroid hormone daughter product calcitriol (also referred to as hormone D). Calcitriol is now known to be involved in the immune system, calcium and bone metabolism, regulation of gene expression; it is linked to prevention and treatment of osteoporosis, cancer, diabetes, and other ravages of aging, including tooth attachment, muscle function and inadvertent falls which can result in bone fractures.

Dr. Robert Heaney, of Creighton University, Omaha, Neb. summarized studies, which point out that all adults should have a much higher blood vitamin D (measured as calcidiol) level, of approximately 75 nanomoles per liter, than previously thought. Swiss scientist Dr Heike Bischoff-Ferrari concurred, presenting the combined findings about vitamin D from several large U.S. health databases.

The consensus of vitamin D nutritional experts present at the Vitamin D Workshop is that current governmental guidelines in all countries with respect to how much daily vitamin D is required simply to maintain bone health and health in general are too low and do not reflect the many scientific advances made in vitamin D and hormone D research over the past 10 years.

There was a general consensus that the blood concentration of vitamin D should at the very least meet or hopefully exceed a minimum desirable serum concentration of 50 nanomoles of vitamin D/liter (or 20 ng/ml). As reviewed in talks at the Workshop by professors from the U.S.A., Canada, The Netherlands and Switzerland, the standard of 50 nanomoles/liter is not achieved by 50 percent of the North American elderly population and by two-thirds of the rest of the world and the situation is frequently not much better in younger subjects.

Even with dietary supplements, the amounts of vitamin D in foods (except for selected fatty fish products) and vitamin supplement products are too low to offer much benefit to adults. As emphasized at the Workshop, vitamin D3 fortification of foods such as bread, milk, or orange juice or vitamin D3 supplementation in daily vitamin capsules has to be very significantly improved and implemented.

Vitamin D3 is also known as the “sunshine vitamin” because it can be formed in our skin by ultra violet light in sunshine. However, it was also a consensus at the workshop that it is not advisable for individuals to prolong their exposure to sunlight to produce the needed higher concentrations of vitamin D because of the well documented effects of sunlight on skin aging and the promotion of skin cancer. This was clearly summarized in a keynote lecture from Professor Barbara Gilchrest, M.D., chair of dermatology at the Boston University Medical School, who described that the very same UVB light or suntan radiation is responsible for vitamin D production in the skin but also for photo ageing and skin cancer.

Finally the experts’ opinion is that more clinical research is needed to define the wide spectrum of the beneficial effects of vitamin D3 on global health and to define the optimal safe levels of vitamin D3 intake. The present upper level of vitamin D intake that is deemed to be safe (2000 International Units/day) must be re-evaluated in light of much existing data acquired over the past 15 years, to be elevated to a higher level, at least to facilitate urgently needed additional clinical studies on the value of higher daily doses of vitamin D3 to the maintenance of better overall health.

What is the Vitamin D Workshop?
The organization known as the Vitamin D Workshop was established in 1973. Since then, 13 Workshops have been held, alternating every three years between Europe and the USA. The primary mission of the Vitamin D Workshop is to conduct scientific meetings on all topics related to vitamin D, but particularly those in which active current research is being conducted. The term “vitamin D” is used in the broadest fashion possible, and includes not only the parent vitamin D itself and its precursors, but any and all metabolites and modified forms (analogs) of vitamin D and its metabolites present in any biological system. Attendance at the meetings is open to all scientists of the world who have an interest in furthering our understanding of the properties and biological purpose of vitamin D and related compounds. When feasible, the Vitamin D Workshop endeavors to publish comprehensive reports of the scientific meeting in Proceedings which will be widely available.

Contact Information

  • Professor Anthony W. Norman
    Chair, Vitamin D Workshop, Inc.
    Department of Biochemistry & Division of Biomedical Sciences
    5456 Boyce Hall
    University of California
    Riverside, CA 92521
    Phone: (951)-827-4777
    FAX: (951)-827-4784

  • Professor Roger Bouillon
    Advisory Committee, Vitamin D Workshop, Inc.
    Laboratory of General Endocrinology
    Onderwijs en Navorsing (9e Verd.)
    B-3000 Leuven, Belgium
    Phone: {011)-32-16-345-970
    Fax:(011) 32-16-345-934

  • Dr. Susan J Whiting
    Professor, Nutrition & Dietetics
    College of Pharmacy & Nutrition
    University of Saskatchewan
    Saskatoon SK S7N 5C9, Canada
    Phone: 306-966-5837
    Fax: 306-966-6377

  • Professor Reinhold Vieth
    Department of Nutritional Sciences, and Department of Laboratory Medicine and Pathobiology, University of Toronto
    Director, Bone and Mineral Laboratory
    Pathology and Laboratory Medicine
    Mount Sinai Hospital
    600 University Ave
    Toronto, Ontario, Canada M5G 1X5
    Phone: 416-586-5920
    Fax: 416--586-8628

  • Professor Paul Lips
    Department of Endocrinology
    VU University Medical Center
    P.O. Box 7057
    1007 MB Amsterdam
    The Netherlands
    Phone: (011) 31-20- 4440614
    Fax: (011) 31-20-4440502

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