You need a lot more vitamin D than you think

Posted on Thu, 24 Feb 11

A new report has found that a minimum of 4,000 IU of vitamin D is required daily to maintain optimal blood levels, a stark contrast to the heavily criticised 600 IU recently stated by the Institute of Medicine.

For the first time a study has looked at the impact of self administration of vitamin D in the general public. Over a 5 year period some 3,677 men and women had their vitamin D levels measured and completed online surveys to monitor vitamin D status and health outcomes. The aim of the study was to assess how much vitamin D is needed to ensure optimal levels in the average person.

It was found that daily supplemental vitamin D levels required maintain optimal blood levels are considerably higher than what was once thought. “We found that daily intakes of vitamin D by adults in the range of 4000-8000 IU are needed to maintain blood levels of vitamin D metabolites in the range needed to reduce by about half the risk of several diseases - breast cancer, colon cancer, multiple sclerosis, and type 1 diabetes," stated Dr Garland, one of the study authors and a leading expert on vitamin D.

The average dose required to ensure that people had adequate vitamin D levels (serum 25(OH)D of at least 40 ng/ml) was 9,600 IU a day from supplements. Importantly, the study also found that this dose was very safe and did not come close to raising blood levels near those considered toxic.

Notably, the lower end of dose required to maintain optimal vitamin D status (4,000 IU daily) was recently found to be safe for everyday use by those nine years of age and older in a report from the National Academy of Sciences Institute of Medicine, but is well above their official recommendation of 600 IU. "Now that the results of this study are in, it will become common for almost every adult to take 4000 IU per day," says Dr Garland.

Watch Dr Robert Heaney, one of the study investigators, comment here:

Reference:

Garland C, et al. Vitamin D Supplement Doses and Serum 25-Hydroxyvitamin D in the Range Associated with Cancer Prevention. Press release before publication, Accessed at http://www.grassrootshealth.net/garland02-11 on 25-02-2011