Policy changes needed to improve vitamin D status - A review published online on July 28, 2010 in the journal Experimental Biology and Medicine recommends the implementation of global policy changes in order to improve the amount of vitamin D that people receive. "Responsible medicine demands that worldwide vitamin D nutritional guidelines reflect current scientific knowledge about vitamin D’s spectrum of activities," write vitamin D expert Anthony Norman of the University of California, Riverside and Roger Bouillon of the Laboratory of Experimental Medicine and Endocrinology at the Katholieke Universiteit Leuven in Belgium.  More...

August 2010 - Vitamin D May Protect Against Crohn’s Disease

Low levels of vitamin D may increase the risk of developing Crohn’s disease, suggest results of a new cell study from Canada.

The active form of vitamin D, known as 1,25-dihydroxyvitamin D (1,25D), is able to maintain proper functioning of the immune system that acts as the body’s first defense against microbial invaders. This lack of defense may lead to an increased inflammatory response, which promotes the development of Crohn’s, according to findings published in the Journal of Biological Chemistry.

"This discovery is exciting, since it shows how an over-the-counter supplement such as vitamin D could help people defend themselves against Crohn’s disease," said study co-author Professor Marc Servant from the Universite de Montreal.

Crohn’s disease, which currently affects approximately one in 400 people in the western world, is incurable so patients mainly seek to control the inflammation, relieve symptoms and prolong remission time.

"It’s a defect in innate immune handling of intestinal bacteria that leads to an inflammatory response that may lead to an autoimmune condition," lead author Professor John White from McGill University explained.

Taking such an observation into account, researchers from McGill and the Universite de Montreal looked at the effects of vitamin D on the beta defensin 2 gene, which plays a key role in the production of antimicrobial proteins, and the NOD2 gene, which alerts cells to the presence of invading microbes. Both genes have been linked to Crohn’s disease.

The researchers found that if NOD2 is deficient or defective, it cannot combat invaders in the intestinal tract and that 1,25-dihydroxyvitamin D was important for switching on the genes to help reduce the risk of Crohn’s.

"There has been some debate as to whether vitamin D deficiency plays a causative role in Crohn’s disease or is merely a consequence of intestinal malabsorption," wrote the researchers. "Our observation that 1,25D signaling is a direct inducer of NOD2 expression argues strongly that vitamin D insufficiency/deficiency does play a causative role in the prevalence of Crohn’s disease."

"The genetics of Crohn’s disease demonstrate that NOD2 insufficiency contributes to development of the disease," they added.

White added that a promising result of their cell study was that it could be quickly put to the test. "Siblings of patients with Crohn’s disease that haven’t yet developed the disease might be well advised to make sure they’re vitamin D sufficient. It’s something that’s easy to do, because they can simply go to a pharmacy and buy vitamin D supplements. The vast majority of people would be candidates for vitamin D," he added. Journal of Biological Chemistry 285(4):2227-2231, 2010

February 2011 -

Cedric Garland, DrPH of the University of California, San Diego School of Medicine and his colleagues recently revealed that significantly higher amounts of vitamin D than what are currently recommended are needed to raise levels to those that help prevent breast cancer, type 1 diabetes and other diseases. The findings were published on the website of Grassroots' Health, a non-profit community service organization dedicated to promoting public awareness about vitamin D, and will appear in the journal Anticancer Research.

Dr Garland, along with Christine B French, Leo L. Baggerly and Robert P. Heaney, MD, analyzed data from a survey of 3,667 men and women whose average age was 51. Serum 25-hydroxyvitamin D levels were measured and online questionnaires were completed every six months over a five year period to ascertain vitamin D levels, vitamin D intake, and health status.

The researchers compared supplemental vitamin D intake reported at the beginning of the study with baseline serum vitamin D levels. "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, who is a professor of family and preventive medicine at UC San Diego Moores Cancer Center. "I was surprised to find that the intakes required to maintain vitamin D status for disease prevention were so high – much higher than the minimal intake of vitamin D of 400 IU/day that was needed to defeat rickets in the 20th century."

"I was not surprised by this," remarked coauthor Heaney, who is a biomedical scientist at Creighton University and an authority on vitamin D. "This result was what our dose-response studies predicted, but it took a study such as this, of people leading their everyday lives, to confirm it."

The study is the first to analyze the relationship of serum vitamin D levels to voluntary vitamin D supplementation in a community setting. While the doses suggested by the study's results might appear high, a report from the National Academy of Sciences Institute of Medicine (IOM) published at the end of last year indicates that 4,000 IU is a safe dosage for everyday use by those nine years of age and older, although the Institute's actual recommendation is much lower.

"Most scientists who are actively working with vitamin D now believe that 40 to 60 nanograms per milliliter is the appropriate target concentration of 25-vitamin D in the blood for preventing the major vitamin D-deficiency related diseases, and have joined in a letter on this topic," Dr Garland noted. "Unfortunately, according to a recent National Health and Nutrition Examination Survey, only 10 percent of the US population has levels in this range, mainly people who work outdoors."

"Now that the results of this study are in, it will become common for almost every adult to take 4000 IU/day," he said. "This is comfortably under the 10,000 IU/day that the IOM Committee Report considers as the lower limit of risk, and the benefits are substantial." (source)