DiseaseProof regular, Llouise—funny spelling, for a funny lady—read yesterday’s Health Points and was intrigued by The New York Times report dealing with vitamin D and sunlight. Here’s the excerpt I pulled:
Complete cloud cover halves the energy of ultraviolet rays, and shade reduces it by 60 percent, according to the National Institutes of Health…After reading this, she was curious to get Dr. Fuhrman’s thoughts on this study; suggesting that vitamin D supplementation might be overrated and needs to be reconsidered. The report is over at PR Web:
…To strike a balance between useful exposure and protection, the N.I.H. recommends an initial exposure of 10 to 15 minutes, followed by application of a sunscreen with an S.P.F. of at least 15. The institutes say this much exposure, at least two times a week, is usually sufficient to provide adequate vitamin D, though some researchers suggest it may not be enough. At the earth’s northern latitudes for much of the year, and at the midlatitudes in winter, the sun does not stay far enough above the horizon (45 degrees) for the angle of the sun’s rays to guarantee an efficient ultraviolet-B bath. Northerners may have to rely on the vitamin D synthesized in the summer or on foods and supplements.
Low blood levels of vitamin D have long been associated with disease, and the assumption has been made that vitamin D supplements may protect against disease. In the light of new knowledge that hundreds of genes are dependent on vitamin D, this assumption needs to be reconsidered.Well, fearing the wrath of a Llouise scorned, I quickly emailed the article over to Dr. Fuhrman and here’s what he had to say about it:
In a report published in the current issue of the journal BioEssays, Trevor Marshall, Ph.D., professor at Australia's Murdoch University School of Biological Medicine and Biotechnology, explains how increased vitamin D intake affects much more than just nutrition or bone health. The paper explains how the Vitamin D Nuclear Receptor (VDR) acts in the repression or transcription of hundreds of genes, including genes associated with diseases ranging from cancers to multiple sclerosis.
"The VDR is at the heart of innate immunity, being responsible for expression of most of the antimicrobial peptides, which are the body's ultimate response to infection," Marshall said. "Molecular biology is now forcing us to re-think the idea that a low measured value of vitamin D means we simply must add more to our diet. Supplemental vitamin D has been used for decades, and yet the epidemics of chronic disease, such as heart disease and obesity, are just getting worse."
You can always find someone who will take the opposite stance to the main thrust of research in the world and the press is always quick to jump on it, even if it is one person's opinion without significant research to prove anything. Lots of this (anti vitamin D supplementation) article is not correct. Vitamin D deficiency does cause rickets. Taking Vitamin D supplement have a long proven history to reduce incidence of rickets. That does not mean that severe calcium deficiency can't contribute to rickets as well.Here's the study Dr. Fuhrman is talking about. From the Archives of Internal Medicine:
Evidence is emerging that more than 17 different types of cancer are likely to be vitamin D sensitive. A recent meta-analysis concluded that 1,000 IU of oral vitamin D per day is associated with a 50% reduction in colorectal cancer incidence. That is taking the supplements result in dramatic benefits.
In general, the most critical outcome related to any intervention is mortality, and a recently published meta-analysis examining the effects of vitamin D supplementation is the most important information we have. The authors of this study evaluated 18 randomized, controlled trials of vitamin D supplementation for any indication. The mean daily dose of vitamin D was 528 IU, and the mean follow-up period was 5.7 years. Vitamin D supplementation was associated with a significant reduction in all-cause mortality compared with placebo.
Background: Ecological and observational studies suggest that low vitamin D status could be associated with higher mortality from life-threatening conditions including cancer, cardiovascular disease, and diabetes mellitus that account for 60% to 70% of total mortality in high-income countries. We examined the risk of dying from any cause in subjects who participated in randomized trials testing the impact of vitamin D supplementation (ergocalciferol [vitamin D2] or cholecalciferol [vitamin D3]) on any health condition.So Llouise, does that answer your questions? And Llouise, keep the comments coming. You rock!
Methods: The literature up to November 2006 was searched without language restriction using the following databases: PubMed, ISI Web of Science (Science Citation Index Expanded), EMBASE, and the Cochrane Library.
Results: We identified 18 independent randomized controlled trials, including 57 311 participants. A total of 4777 deaths from any cause occurred during a trial size–adjusted mean of 5.7 years. Daily doses of vitamin D supplements varied from 300 to 2000 IU. The trial size–adjusted mean daily vitamin D dose was 528 IU. In 9 trials, there was a 1.4- to 5.2-fold difference in serum 25-hydroxyvitamin D between the intervention and control groups. The summary relative risk for mortality from any cause was 0.93 (95% confidence interval, 0.87-0.99). There was neither indication for heterogeneity nor indication for publication biases. The summary relative risk did not change according to the addition of calcium supplements in the intervention.
Conclusions: Intake of ordinary doses of vitamin D supplements seems to be associated with decreases in total mortality rates. The relationship between baseline vitamin D status, dose of vitamin D supplements, and total mortality rates remains to be investigated. Population-based, placebo-controlled randomized trials with total mortality as the main end point should be organized for confirming these findings.