'D' Levels More Important than IUs: Scientists

TORONTO, Nov. 29, 2010 /CNW/ - Vitamin D blood levels - and not vitamin D intake itself - should be the focus of media coverage of this Tuesday's anticipated Institutes of Medicine (IOM) revised North American vitamin D recommendations, according to a worldwide coalition of 41 vitamin D researchers.

"We hope everyone sees the big picture that new daily vitamin D recommendations are only the means to the more-important end: a person's actual vitamin D blood serum level," says Dr. Robert Heaney, a Creighton University vitamin D researcher with 50 years in the field and more than 400 published papers. Heaney is one of eight experts on the D-Action coalition who will be available for interviews this week.

Even with the IOM announcement this week expected to increase daily vitamin D recommendations, Vitamin D should not be approached as a "one-size-fits-all" either for individuals or for diseases now known to be impacted by low vitamin D levels.

Current vitamin D recommendations are based almost solely on bone health. But research in the last decade firmly establishes vitamin D's role at much higher intakes for growth regulation in diverse tissues. Serum 25-hydroxyvitamin D concentrations indicated in hundreds of peer-reviewed studies for prevention and risk reduction of disease range from:

- 20 ng/ml to prevent 99% of rickets and acute osteomalacia.
- 32 ng/ml for adequate calcium absorption for bone strength and health.
- 35 ng/ml for reduction in risks of myocardial infarction.
- 38 ng/ml for reduction in risk of colon cancer, viral and bacterial respiratory infections, including influenza
- 60+ ng/ml for reduction in incidence breast cancer

The D-Action Consortium of 41 vitamin D researchers, organized by GrassrootsHealth (www.GrassrootsHealth.org), issued a "Scientists' Call to Action" in 2007 calling for:

- Serum 25-hydroxy vitamin D concentration of 40-60 ng/ml (100-150 nmol/L).

- Minimal daily vitamin D intake of at least 2,000 IU to maintain those concentrations (although some individuals may require higher intake to attain the specified serum concentrations).

With a current population average of about 25 ng/ml, 1,000 IU/day would only raise half the population to the 35- 40 ng/ml serum concentration. At least 2,000 IU/day would be needed to raise almost everyone from 25 ng/ml to the minimum serum concentration of 40 ng/ml (100 nmol/L).

The Scientists' Call to Action on Vitamin D and list of signers are available for review in Garland CF et al. Vitamin D for cancer prevention: Global perspective. Annals of Epidemiology 2009;19:468-83, Figure 10.