Group items tagged

Opinion of the Scientific Committee on Food on the Tolerable Upper Intake Level of Vitamin D (expressed on 4 December 2002)

I have been inundated with letters asking about Professor Marshall's recent "discovery." Some have written that to say they have stopped their vitamin D and are going to avoid the sun in order to begin the "Marshall protocol." The immediate cause of this angst is two publications, a press article in Science Daily about Professor Marshall's "study" (which is no study but simply an opinion) in BioEssays. Dr. Trevor Marshall has two degrees, both in electrical engineering

Diagnosis and treatment of vitamin D deficiency. Cannell JJ, Hollis BW, Zasloff M, Heaney RP. Expert Opin Pharmacother. 2008 Jan;9(1):107-18. PMID: 18076342 DOI 10.1517/14656566.9.1.107

Cod liver oil, vitamin A toxicity, frequent respiratory infections, and the vitamin D deficiency epidemic. Cannell JJ, Vieth R, Willett W, Zasloff M, Hathcock JN, White JH, Tanumihardjo SA, Larson-Meyer DE, Bischoff-Ferrari HA, Lamberg-Allardt CJ, Lappe JM, Norman AW, Zittermann A, Whiting SJ, Grant WB, Hollis BW, Giovannucci E. Ann Otol Rhinol Laryngol. 2008 Nov;117(11):864-70. Review. PMID: 19102134 Until we have better information on doses of vitamin D that will reliably provide adequate blood levels of 25(OH)D without toxicity, treatment of vitamin D deficiency in otherwise healthy children should be individualized according to the numerous factors that affect 25(OH)D levels, such as body weight, percent body fat, skin melanin, latitude, season of the year, and sun exposure.2 The doses of sunshine or oral vitamin D3 used in healthy children should be designed to maintain 25(OH)D levels above 50 ng/mL. As a rule, in the absence of significant sun exposure, we believe that most healthy children need about 1,000 IU of vitamin D3 daily per 11 kg (25 lb) of body weight to obtain levels greater than 50 ng/mL. Some will need more, and others less. In our opinion, children with chronic illnesses such as autism, diabetes, and/or frequent infections should be supplemented with higher doses of sunshine or vitamin D3, doses adequate to maintain their 25(OH)D levels in the mid-normal of the reference range (65 ng/mL) - and should be so supplemented year round. Otolaryngologists treating children are in a good position to both diagnose and treat vitamin D deficiency.

"So why is Dr Vieth so frustrated? You might think he'd have cause for celebration. But for him and other vitamin D researchers around the world, the good news comes with a bitter aftertaste. They believe they can prove vitamin D could help millions live longer and be healthier and yet they have not been able to convince their own governments. In the US and Canada, official vitamin D policy is set by the Institute of Medicine. And in the opinion of Vieth, the current recommendations - 200 International Units per day for people under 50, 400 for people aged 51-70, and 600 for those 71 and older - are outrageously low. Bruce Hollis, professor of paediatrics at the Medical University of South Carolina, calls 400 IU a day "a joke". That's because the best research suggests that to achieve the higher vitamin D blood levels associated with disease prevention, most adults in the US would need to take 1,000-2,000 IU a day: five to 10 times more than the current official recommendation for adult In 1999, Reinhold Vieth (pictured right) published a review of vitamin D research in response to the IOM conclusions. In it, he argued that there was no evidence that amounts lower than 20,000 IU a day could be toxic. "Throughout my preparation of this review, I was amazed at the lack of evidence supporting statements about the toxicity of moderate doses of vitamin D," Vieth wrote. Studies have since shown 10,000 IU a day of vitamin D to be safe. While any substance will become toxic in excess, vitamin D researchers today accept that the current vitamin D recommendations could be more than quadrupled with no fear of toxicity.!

This article discusses our experience at the one-day Institute of Medicine workshop on vitamin D and calcium. Both of us had an opportunity to make comments before the committee. Here are Paul's comments and slides and here are Amy's comments and slides. Note that our 2009 paper in Autoimmunity Reviews[1] discusses some of the science we allude to in further detail.

Evidence-based decision making on micronutrients and chronic disease: long-term randomized controlled trials are not enough. Ames BN, McCann JC, Stampfer MJ, Willett WC. Am J Clin Nutr. 2007 Aug;86(2):522-3; author reply 523-4. PMID: 17684228

Diagnosis and treatment of vitamin D deficiency. Cannell JJ, Hollis BW, Zasloff M, Heaney RP. Expert Opin Pharmacother. 2008 Jan;9(1):107-18. PMID: 18076342 DOI 10.1517/14656566.9.1.107

Bikle DD. What is new in vitamin D: 2006-2007. Curr Opin Rheumatol. 2007 Jul;19(4):383-8. PMID: 17551371 [PubMed - in process]

Zittermann A, Schleithoff SS, Koerfer R. \nVitamin D and vascular calcification.\nCurr Opin Lipidol. 2007 Feb;18(1):41-6. Review.\nPMID: 17218831 [PubMed - indexed for MEDLINE

Diagnosis and treatment of vitamin D deficiency. Cannell JJ, Hollis BW, Zasloff M, Heaney RP. Expert Opin Pharmacother. 2008 Jan;9(1):107-18. PMID: 18076342 The recent discovery - in a randomised, controlled trial - that daily ingestion of 1100 IU of colecalciferol (vitamin D) over a 4-year period dramatically reduced the incidence of non-skin cancers makes it difficult to overstate the potential medical, social and economic implications of treating vitamin D deficiency. Not only are such deficiencies common, probably the rule, vitamin D deficiency stands implicated in a host of diseases other than cancer. The metabolic product of vitamin D is a potent, pleiotropic, repair and maintenance, secosteroid hormone that targets > 200 human genes in a wide variety of tissues, meaning it has as many mechanisms of action as genes it targets. A common misconception is that government agencies designed present intake recommendations to prevent or treat vitamin D deficiency. They did not. Instead, they are guidelines to prevent particular metabolic bone diseases. Official recommendations were never designed and are not effective in preventing or treating vitamin D deficiency and in no way limit the freedom of the physician - or responsibility - to do so. At this time, assessing serum 25-hydroxy-vitamin D is the only way to make the diagnosis and to assure that treatment is adequate and safe. The authors believe that treatment should be sufficient to maintain levels found in humans living naturally in a sun-rich environment, that is, > 40 ng/ml, year around. Three treatment modalities exist: sunlight, artificial ultraviolet B radiation or supplementation. All treatment modalities have their potential risks and benefits. Benefits of all treatment modalities outweigh potential risks and greatly outweigh the risk of no treatment. As a prolonged 'vitamin D winter', centred on the winter solstice, occurs at many temperate latitudes, ≤ 5000 IU (125 μg) of vitamin D/d

"This is not one of our usual hour-long live discussions. Rather, this is an online question-and-answer session. Your questions and Dr. Vieth's answers will appear at the bottom of this page after 1 p.m. EDT today."

Vitamin D and cardiovascular disease risk. Michos ED, Melamed ML. Curr Opin Clin Nutr Metab Care. 2008 Jan;11(1):7-12. Review. PMID: 18090651 doi: 10.1097/MCO.0b013e3282f2f4dd Summary: Vitamin D deficiency is easy to screen for and easy to treat with supplementation. Further larger observational studies and randomized clinical trials are, however, needed to determine whether vitamin D supplementation could have any potential benefit in reducing future cardiovascular disease events and mortality risk.