Main article: Forms and structure of vitamin D
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A number of studies have suggested that patients with chronic inflammatory diseases are deficient in 25-hydroxyvitamin D (25-DThe vitamin D metabolite widely (and erroneously) considered best indicator of vitamin D "deficiency." Inactivates the Vitamin D Nuclear Receptor. Produced by hydroxylation of vitamin D3 in the liver.) and that consuming greater quantities of vitamin D, which further elevates 25-D levels, alleviates disease symptoms.
Some years ago, molecular biology identified 25-D as a secosteroid. Secosteroids would typically be expected to depress inflammationThe complex biological response of vascular tissues to harmful stimuli such as pathogens or damaged cells. It is a protective attempt by the organism to remove the injurious stimuli as well as initiate the healing process for the tissue., which is in line with the reports of short-term symptomatic improvement. The simplistic first-order mass-action model used to guide the early vitamin studies is now giving way to a more complex description of action.
When active, the Vitamin D nuclear receptorA nuclear receptor located throughout the body that plays a key role in the innate immune response. (VDRThe Vitamin D Receptor. A nuclear receptor located throughout the body that plays a key role in the innate immune response.) affects transcription of at least 913 genes and impacts processes ranging from calcium metabolism to expression of key antimicrobial peptidesBody’s naturally produced broad-spectrum antibacterials which target pathogens.. Additionally, recent research on the Human MicrobiomeThe bacterial community in the human body. Many species in the microbiota contribute to the development of chronic disease. shows that bacteria are far more pervasive than previously thought, dramatically increasing the possibility that the spectrum of chronic diseases is bacterial in origin.
Emerging molecular evidence suggests that symptomatic improvements among those administered vitamin D is the result of 25-D’s ability to temper bacterial-induced inflammation by slowing VDR activity. While this results in short-term palliation, persistent pathogens that influence disease progression proliferate over the long-term.
Main article: Forms and structure of vitamin D
All forms of vitamin D are secosteroids, sharing a close structural and functional resemblance to steroids. The full implications of a “vitamin” acting as a steroid has yet to be fully appreciated by many in the research community. The overlap between steroids and secosteroids is key to understanding the Marshall PathogenesisA description for how chronic inflammatory diseases originate and develop.. It explains how this “vitamin” can exert short-term palliative effects and long-term harm. Patients on the MP are advised to avoid consuming vitamin D, because of its immunomodulatory effects.
There are a number of vitamin D metabolites in the body. The steps by which one form of vitamin D changes into the next are as follows:
It's important to understand that the body tightly regulates the different forms as it might a steroid.
Main article: Metabolism of vitamin D and the Vitamin D Receptor
Related section: Sunlight can be immunosuppressive
Supplemental vitamin D has been widely lauded for conferring immunosuppressive effects.
Vitamin D affects the immune system at many levels and by a number of mechanisms…. Vitamin D has multiple immunosuppressant properties…. On the whole, vitamin D confers an immunosuppressive effect.
Aronson, Amital, and Shoenfeld 2)
Supplemental vitamin D is being touted as having a wide range of benefits in different diseases. A puzzling picture that emerges from the totality of the diseases that they are claimed to affect beneficially, is the belief that supplemental vitamin D will both reduce infections and suppress the immune system at the same time. While it is clear that there exist substances that can be “immunomodulating”, implicating that it can increase production/release of both immunosuppressive and immune activating substances, the important question is what the overall effect is. It is hard to envision that a substance can have strong anti-infectious properties while at the same time having a strong immune suppressive effect.
In studies on acute respiratory tract infection3), tuberculosis4) and overall infections5), the effects of vitamin D have been mixed (and largely unsuccessful) in terms of reducing infectious burden.
A complete evaluation of the above mentioned studies, and the differences between them that can help explain the different results, is not suited for this article. However, on a general basis, one of the reasons for differing effects may be that vitamin D works differently in relatively healthy people as compared to sick people. Thus, vitamin D supplementation may give a marginal benefit in preventing infections in healthy people (see section below), but not in sick people. As of today (Dec 2012) we are not aware of any studies that have shown an actual reduction in infections in sick people (for instance tuberculosis or COPD) by vitamin D supplementation, as measured by culture or genetical detection methods. Furthermore, a general trend seems to be that apparent beneficial effects on infection in healthy people are not seen in individuals who have 25-hydroxyvitamin D levels within the normal range6)7)8), adding, as a side point, further weight to the mega dose vitamin D supplementation craze being without merit.
It is however not certain, in spite of some reported benefits in a few studies, that any level of supplementation is beneficial in terms of reducing infection. The studies are still too few to draw firm conclusions, and publication bias, as in any field science, may skew the overall results. Another factor which makes the reported benefits doubtful is that not all studies have reported an actual reduction in infection, but merely symptom based outcomes. Symptom based outcomes are relevant, but in light of the symptom reducing effects therapies that are immune suppressive may have, it is not clear that symptom reduction in the vitamin D supplementation studies are due to an actual reduction in infection. Further, most of the symptoms in upper respiratory tract infections are caused by the body's own immune response, and not the infectious agents9).
In sick people vitamin D supplementation increases infectious burden, and suppresses the immune system:
The following articles discuss the role of vitamin D in select diseases. A more complete list of diseases that have been shown to have low level of 25-D is also available.
Main article: Osteoporosis and osteopenia
Related article: Secondary hyperparathyroidism
Both osteoporosis and osteopenia are diseases marked by a decrease in bone mineral density. Osteopenia is a less severe form of and sometimes precursor to osteoporosis. The loss of bone mass leads to a porous bone structure, frequent fractures, and delayed healing.
Among doctors, and even many researchers, it is conventional wisdom that vitamin D supplementation reverses osteopenia and osteoporosis. However, a growing body of interventional trials and molecular evidence shows this is not the case.
Thumbs Down on Calcium and Vitamin D to Prevent Hip Fracture January 2018
Supplementation and Fracture Incidence in Community-Dwelling Older Adults: A Systematic Review and Meta-analysis December 2017
Vitamin D Supplements Don't Help Bone Health, Meta-Study Finds October 2018
Instead, current research has demonstrated that osteoporosis and osteopenia are often the direct result of infection with the Th1 pathogens, a metagenomic microbiotaThe community of bacterial pathogens including those in an intracellular and biofilm state which cause chronic disease., which produce inflammatory cytokinesAny of various protein molecules secreted by cells of the immune system that serve to regulate the immune system. and inactivate the Vitamin D ReceptorA nuclear receptor located throughout the body that plays a key role in the innate immune response.. It seems the only way to achieve long-term reversal of bone loss is to kill the Th1 pathogensThe community of bacterial pathogens which cause chronic inflammatory disease - one which almost certainly includes multiple species and bacterial forms. driving the disease process.
Main article: Rickets (osteomalacia)
Rickets (osteomalacia) is a softening of the bones that leads to fractures and deformity. The majority of cases of rickets occur among children in developing countries who suffer from severe malnutrition. The disease is cited as a primary reason for consuming vitamin D regularly even though research has demonstrated that rickets is not caused by vitamin D deficiency but by hypophosphatemia.
The latest molecular evidence does not support adding high levels of vitamin D to the food chain in the name of “preventing rickets.” The health of the public would be much better served by regulations ensuring that they obtain adequate calcium and phosphorous rather than vitamin D.
Main article: Vitamin D and cancer
A variety of studies have suggested that vitamin D protects against cancer. This seemingly intuitive proposition is supported by neither epidemiological nor molecular evidence. In fact, the very opposite is true. This article reviews why this body of research is most likely incorrect – or at the very least, much more complicated than articles in the popular media would have a person believe.
According to the Marshall Pathogenesis, alteration of vitamin D metabolism by a pathogenic microbiota prevents any benefit from vitamin D supplementation.
Main article: Cardiovascular disease
According to a 2010 paper by Swales and Wang, “despite substantial clinical evidence linking vitamin D deficiency with increased cardiovascular risk, it remains to be established whether this represents a causal association.”17) Indeed, data from a 2011 prospective, randomized, placebo-controlled trial[cite needed]18) has cast real doubt on the alleged cardioprotective benefits of vitamin D. Researchers performing a small study report that treatment with vitamin D for four months had no significant effect on endothelial function, vascular stiffness, or inflammation in healthy postmenopausal women.
A recent cross-sectional study involving 340 African Americans with type 2 diabetes found that serum 25-hydroxyvitamin D levels were positively associated with increased calcified atherosclerotic plaque in the aorta and carotid arteries.19)
Main article: Sunshine or light exposure as a therapy
Related articles: Latitude studies, Palliative vs. curative treatments
According to the Marshall PathogenesisA description for how chronic inflammatory diseases originate and develop., light-related changes in mood can be attributed to fluctuations in 1,25-dihydroxyvitamin DPrimary biologically active vitamin D hormone. Activates the vitamin D nuclear receptor. Produced by hydroxylation of 25-D. Also known as 1,25-dihydroxycholecalciferol, 1,25-hydroxyvitamin D and calcitirol. (1,25-DPrimary biologically active vitamin D hormone. Activates the vitamin D nuclear receptor. Produced by hydroxylation of 25-D. Also known as 1,25-dihydroxycholecalciferol, 1,25-hydroxyvitamin D and calcitirol.). Such reactions exist in people who suffer from “seasonal affective disorder” as well as those who are addicted to or dependent upon tanning.
Contrary to popular belief, epidemiological research points to an increase in suicide across countries during the beginning of the summer months when people tend to get more light exposure.
Light exposure does nothing to resolve underlying disease state and can actually delay progress for Marshall ProtocolA curative medical treatment for chronic inflammatory disease. Based on the Marshall Pathogenesis. (MP) patients. Certainly prolonged light exposure has been shown to increase skin melanoma – the World Health Organization now categorizes tanning beds under the highest cancer risk category.20)
MP patients who have completed the treatment have been able to attest to the fact that sunshine is not necessary for good health or happiness.
Despite what some researchers have argued, latitude studies that try to tie ambient solar UV radiation to prevalence of disease have been inconclusive.
Impact of 25-hydroxyvitamin D, free and bioavailable fractions of vitamin D, and vitamin D binding protein levels on metabolic syndrome components 21)
Main article: Pregnancy and vitamin D
Related article: Pregnancy and fertility
1,25-DPrimary biologically active vitamin D hormone. Activates the vitamin D nuclear receptor. Produced by hydroxylation of 25-D. Also known as 1,25-dihydroxycholecalciferol, 1,25-hydroxyvitamin D and calcitirol. rises by 40% in the early pregnant decidua, meaning that its ability to dysregulate the nuclear receptors and the antimicrobial peptidesBody’s naturally produced broad-spectrum antibacterials which target pathogens. (AmPs) they express is particularly prevalent during the first trimesters of pregnancy. The subsequent decrease in immune function slows immunopathologyA temporary increase in disease symptoms experienced by Marshall Protocol patients that results from the release of cytokines and endotoxins as disease-causing bacteria are killed., resulting in symptomatic relief. But when the surge in 1,25-D disappears after pregnancy, AmP expression and immunopathology increase once again, leading to exacerbation of disease symptoms. This may explain why some women with autoimmune disease experience periods of palliation during gestation only to become increasingly symptomatic after giving birth.
Related articles: Innate immunity, About Radio Frequency Radiation
One of the abiding weaknesses of studies on the effects of vitamin D on health is that researchers simply do not follow subjects consuming the secosteroid for a sufficient period of time. Instead, they tend to track subjects over the course of weeks, months, or one or two years, during the period of time when study participants are usually feeling the palliative effects of the steroid.
This practice is a mistake as it does not account for the long-term immunosuppressive effects of a steroid. For example, the U-shaped relationship between vitamin D levels and long-term outcome in large cohort 22)
<mainrelatedarticles> Bias in observational epidemiological studies, Latitude studies</article>
It is arguably impossible to sufficiently control for the socioeconomic factors, which drive a person to participate in a therapy or take a supplement. The case of hormone replacement therapy (HRT) is instructive. For decades, researchers thought that HRT prevented disease, but it was ultimately shown that it caused it.
Studies of vitamin D's efficacy are especially fraught with challenges. For one, the secosteroid is palliative and the negative side effects can only be seen after decades of use. Also, people who take vitamin D are demonstrably different than those who don't. They almost always have a higher socioeconomic status.
Not all studies on vitamin D's efficacy are observational, but those that are may warrant a special amount of skepticism.
Main article: Mistaking correlation for causation in vitamin D studies
Related article: Diseases associated with low levels of 25-D
Many vitamin D studies suffer from methodological errors including bias inherent to using self-selected subjects and insufficient followup, but perhaps their most egregious liability comes in mistaking correlation for causation. 23)
It's undisputed that a wide array of studies point to the fact that 25-hydroxyvitamin D (25-D) – typically referred to in the media as vitamin D – is low in people with numerous chronic inflammatory diseases. However, these studies fail to prove that low 25-D causes disease. Even so, some studies assume that doubling serum levels of 25-D would drastically reduce mortality.24)
In fact, molecular science has revealed that the levels of the vitamin D metabolites through a series of intricate and carefully controlled feedback pathways, mechanisms that belie the simplistic first-order mass-action model used to guide the short-sighted vitamin studies. Also, epidemiological evidence suggests that while 25-D is low in chronic disease, 1,25-D (1,25-dihydroxyvitamin D) tends to be very high, an observation which is at odds with the theory that vitamin D deficiency causes or exacerbates disease.
There have been lots of observational studied showing an association between various diseases and vitamin D deficiency, but there is not any evidence yet that that is a casual relationship… it may be that vitamin D deficiency is a marker of ill health.
Dr. Ruth McQuillan, University of Edinburgh
According to Professor Roger Bouillon of the University of Leuven, “over one billion” people worldwide need to increase their vitamin D intake due to vitamin D “deficiency.”25) One Saudi study concluded that 87.8% of healthy men were “deficient.”
Yet, observational studies show that populations which avoid vitamin D consumption have naturally low levels of 25-D and remain healthy with such levels.
The Vitamin D Council, an organization that advocates vitamin D supplementation, stated:
One of the great mysteries in human biology is the fact that most human breast milk is deficient in vitamin D. How could Nature overlook such an important nutrient in the “perfect food”?
Vitamin D Council
One research team, studying patients with xeroderma pigmentosum, a genetic disorder in which patients are unable to repair damage caused by ultraviolet light, found that vitamin D levels are maintained even when patients practice at least six years of rigorous photoprotection and not supplementing with vitamin D. More importantly, the researchers also concluded that the clinical manifestations of vitamin D “deficiency” were absent.
The patients all wore protective clothing and sunscreens when outdoors. Estimated mean vitamin D intake was normal. The mean values of serum 25-OHD were low normal, but 1,25-(OH)2D, calcium, ionized calcium and parathyroid hormone levels were normal [italics added]…. Despite rigorous sun protection normal vitamin D levels can be maintained in ambulatory patients with XP.
Armando Sallitto et al.34)
Numerous studies have identified patient populations that are “deficient” in vitamin D. Patients suffering from obesity, schizophrenia, fibromyalgia, multiple sclerosis, autism, etc. all seem to be suffering from vitamin D deficiency. One could list hundreds of such studies.
Although it is not unheard of, few seem to explore the possibility that a low 25-D is the result of disease. Perhaps it is because researchers conceptualize vitamin D as they might a resource which gets used up and needs to be replenished – not unlike gasoline when a car runs low. This metaphor is not at all apt, because vitamin D is regulated like the steroid it is.35) 36)
Large segments of the population are consuming vitamin D at historic levels. Like the first-line treatment for many autoimmune diagnoses, the corticosteroidA first-line treatment for a number of diseases. Corticosteroids work by slowing the innate immune response. This provides some patients with temporary symptom palliation but exacerbates the disease over the long-term by allowing chronic pathogens to proliferate. Prednisone, vitamin D temporarily reduces symptoms of disease, but long-term use dramatically increases the odds of disease relapse.37)
In practice, widespread and systematic supplementation of vitamin D may serve to drive a kind of self-fulfilling prophesy. When whole populations are given large amounts of vitamin D, the only members of that population who remain “deficient” are those whose immune systems are fighting disease by actively downregulating 25-D. In other words, the more rigorously vitamin D is added to milk, juice, snack bars, and breakfast cereals, the less likely it is that someone has low levels of vitamin D but no chronic disease.
According to the Marshall Pathogenesis, limited amounts of vitamin D may be helpful for a time to healthy people. Because the body is able to properly regulate the VDR, ingested vitamin D is rapidly converted into 1,25-D, which activates the VDR. This may explain the one (barely) significant finding from a 2011 Cochrane systematic review.38) (Publication bias may have also tilted the findings towards intervention.) However, this is certainly no basis for forced fortification.
As opposed to certain treatments which employ sunshine or light therapy, patients on the Marshall ProtocolA curative medical treatment for chronic inflammatory disease. Based on the Marshall Pathogenesis. (MP) use the VDR agonistA substance such as olmesartan (Benicar) or 1,25-D which activates the Vitamin D Receptor and transcribes the genes necessary for a proper innate immune response., olmesartanMedication taken regularly by patients on the Marshall Protocol for its ability to activate the Vitamin D Receptor. Also known by the trade name Benicar. , and pulsed, low-dose antibiotics to gradually eliminate the Th1 pathogensThe community of bacterial pathogens which cause chronic inflammatory disease - one which almost certainly includes multiple species and bacterial forms.. Patients on the treatment must refrain from supplementing with vitamin D or eating any foods that contain vitamin D. These measures allow 25-D levels to drop to a point where the VDR can most optimally activate the innate immune system.
Because the vitamin D metabolites are dysregulated in chronic disease, most patients on the MP also become sensitive to light. Although light sensitivity improves as the Th1 pathogens are killed, most patients must avoid bright sunlight and block bright light in the eyes with special sunglasses during the healing process. However, once the Th1 pathogens have been killed and the vitamin D metabolites have re-stabilized, patients are able to tolerate sunlight and bright lights once again.
broken link Vitamin D Intolerance – “I get sick as a dog.” Lyme and autoimmune patients commiserate with one another over feeling worse after taking vitamin D.
* Skepticism Grows Regarding Widespread Vitamin D Supplementation No longer a working link
http://www.medscape.com/viewarticle/753924 discussion of studies found for Ref.#18 in Cardiovascular disease, one with results expected 2016/7 SOURCING
This challenges the entire concept of vitamin D “deficiency” and helps explain why many patients with inflammatory disease present with low levels of 25-D even when they are consuming large amounts of the secosteroid or are exposed to abundant sunlight.39) 40)
Read full text! Includes info about rickets, etc.
Allergy Asthma Clin Immunol. 2009 Nov 19;5(1):8.
Introduction of oral vitamin D supplementation and the rise of the allergy pandemic.41)
Wjst M. Institute of Genetic Medicine, EURAC research, Drususallee 1, I-39100 Bozen, Italy. wjst@helmholtz-muenchen.de Abstract The history of the allergy pandemic is well documented, enabling us to put the vitamin D hypothesis into its historical context. The purpose of this study is to compare the prevalence of rickets, vitamin D supply, and allergy prevalence at 50-year intervals by means of a retrospective analysis of the literature since 1880. English cities in 1880 were characterized by an extremely high rickets prevalence, the beginning of commercial cod liver oil production, and the near absence of any allergic diseases. By 1930 hay fever prevalence had risen to about 3% in English-speaking countries where cod liver oil was preferentially used for the treatment of rickets. In 1980 vitamin D was used nation-wide in all industrialized countries as supplement to industrial baby food, thus eradicating nearly all cases of rickets. At the same time the allergy prevalence reached an all-time high, affecting about 30% of the population. Time trends are therefore compatible with the vitamin D hypothesis although direct conclusions cannot be drawn. It is interesting, however, to note that there are at least two earlier research papers linking synthesized vitamin D intake and allergy (Reed 1930 and Selye 1962) published prior to the modern vitamin D hypothesis first proposed in 1999. PMID: 20016691
J Steroid Biochem Mol Biol. 2010 Jul;121(1-2):467-70. Epub 2010 Mar 7.Low serum levels of 25-hydroxyvitamin D (25-OHD) among psychiatric out-patients in Sweden: relations with season, age, ethnic origin and psychiatric diagnosis.
Humble MB, Gustafsson S, Bejerot S. Department of Clinical Neuroscience, Division of Psychiatry, St. Göran, Karolinska Institutet, Stockholm, Sweden. mats.humble@gmail.com Abstract In a chart review at a psychiatric out-patient department, latitude 59.3 degrees N, a sample of patients with tests of serum 25-hydroxy-vitamin D (25-OHD) and plasma intact parathyroid hormone (iPTH) was collected, together with demographic data and psychiatric diagnoses. During 19 months, 117 patients were included. Their median 25-OHD was 45 nmol/l; considerably lower than published reports on Swedish healthy populations. Only 14.5% had recommended levels (over 75). In 56.4%, 25-OHD was under 50 nmol/l, which is related to several unfavourable health outcomes. Seasonal variation of 25-OHD was blunted. Patients with ADHD had unexpectedly low iPTH levels. Middle East, South-East Asian or African ethnic origin, being a young male and having a diagnosis of autism spectrum disorder or schizophrenia predicted low 25-OHD levels. Hence, the diagnoses that have been hypothetically linked to developmental (prenatal) vitamin D deficiency, schizophrenia and autism, had the lowest 25-OHD levels in this adult sample, supporting the notion that vitamin D deficiency may not only be a predisposing developmental factor but also relate to the adult patients' psychiatric state. This is further supported by the considerable psychiatric improvement that coincided with vitamin D treatment in some of the patients whose deficiency was treated. PMID: 20214992
Some good studies here?
May be a good idea to put bulleted list of vitamin D articles here… or should I link them with a tag?
That 25 vitamin D slows VDR activity needs some references
Vitamin D study suggests no mortality benefit for older womenOctober 31, 2011 | Contact: David Orenstein | 401-863-1862 A study of postmenopausal women found no significant mortality benefit from vitamin D after controlling for health risk factors such as abdominal obesity. The only exception was that thin-waisted women with low vitamin D levels might face some risk. The results agree with advice issued last year by the Institute of Medicine that cautioned against vitamin D having a benefit beyond bone health. PROVIDENCE, R.I. [Brown University] — Doctors agree that vitamin D promotes bone health, but a belief that it can also prevent cancer, cardiovascular disease and other causes of death has been a major health controversy. Consistent with advice issued last fall by the Institute of Medicine, a new study finds that vitamin D did not confer benefits against mortality in postmenopausal women after controlling for key health factors such as abdominal obesity.
Charles Eaton, M.D. “There’s not enough evidence to do anything about vitamin D levels if it’s not in regard to bone health.” “What we have is clinical trial evidence that for the most part vitamin D doesn’t seem to be helpful for conditions where people thought it might,” said study lead author Charles Eaton, professor of family medicine and of epidemiology in the Warren Alpert Medical School of Brown University and a physician at Memorial Hospital in Pawtucket, R.I. “The best we can tell is that there isn’t an association. Once we took into account these other factors, high levels didn’t provide a benefit and low levels didn’t put you at risk.”
In the study, published online Oct. 26 in the American Journal of Clinical Nutrition, Eaton led an analysis of data from 2,429 postmenopausal women aged 50 to 79 who participated in the broad-based Women’s Health Initiative study, in which Eaton and many co-authors were investigators. They tracked blood levels of vitamin D in the women and their mortality over a 10-year period. They not only looked at death from all causes but also focused on cancer and cardiovascular disease.
In all, 225 of the women died, including 79 from cardiovascular disease and 62 from cancer.
Eaton said he expected to find some protective effect against such mortality from vitamin D, and at first glance — controlling only for age, ethnicity, and whether women took part in a calcium and vitamin D supplement trial — that’s what the data showed. But what was apparent in the data was that the women with the lowest levels of vitamin D also had a lot of other negative health indicators. The team therefore controlled for several more key health factors, such as smoking, history of cardiovascular disease, history of cancer, alcohol consumption, and waist circumference. The additional controls, especially waist circumference, which is a measure of abdominal obesity, eroded the statistical significance of vitamin D’s seemingly protective effects down to nothing.
The one exception was that women with thinner waistlines (less than 35 inches) and with the lowest vitamin D levels seemed to have a greater risk of “all-cause” mortality within the 10-year analysis period. That result, however, was right on the borderline of statistical significance.
“If you are thin, this data suggest that maybe low vitamin D levels are potentially harmful and you should talk to your doctor about what to do about them,” Eaton said.
Eaton said he and his co-authors can only speculate about why abdominal obesity was an especially important and powerful factor to control for in their analysis. In the study they note that abdominal obesity is associated with several negative health indicators that may overwhelm any modest benefit vitamin D might have. They also point out that fat tissue can store vitamin D, possibly meaning that women with larger waistlines are storing more of the vitamin than their blood serum levels alone would reveal.
More research into the connections between abdominal fat and the health effects of vitamin D could help resolve the question, Eaton said. He also said that a major new trial of vitamin D supplements and health called “VITAL” is getting underway and will likely inform the broader controversy about what vitamin D is good for.
For now, Eaton said, “there’s not enough evidence to do anything about our vitamin D levels if it’s not in regard to bone health.”
The other authors on the paper are Anne McTiernan and Alicia Young of the Fred Hutchinson Cancer Research Center in Seattle; Matthew Allison of the University of California–San Diego; Jennifer Robinson of the University of Iowa; Lisa Martin of the George Washington University Medical Center; Lewis Kuller of the University of Pittsburgh; Karen Johnson of the University of Tennessee; J. David Curb of the University of Hawaii; Linda Van Horn of Northwestern University; Simin Liu of the University of California–Los Angeles; and JoAnn Manson of Harvard Medical School.
The Women’s Health Initiative was funded by the National Heart, Lung and Blood Institute.
Editors: Brown University has a fiber link television studio available for domestic and international live and taped interviews, and maintains an ISDN line for radio interviews. For more information, call (401) 863-2476.
From: Bane Date: 2011-11-01 16:27:18 Reply: http://www.marshallprotocol.com/reply.php?topic_id=13718
Vitamin D study suggests no mortality benefit for older women
http://news.brown.edu/pressreleases/2011/10/vitamind
Doctors agree that vitamin D promotes bone health, but a belief that it can also prevent cancer, cardiovascular disease and other causes of death has been a major health controversy. Consistent with advice issued last fall by the Institute of Medicine, a new study finds that vitamin D did not confer benefits against mortality in postmenopausal women after controlling for key health factors such as abdominal obesity.
“What we have is clinical trial evidence that for the most part vitamin D doesn’t seem to be helpful for conditions where people thought it might,” said study lead author Charles Eaton, professor of family medicine and of epidemiology in the Warren Alpert Medical School of Brown University and a physician at Memorial Hospital in Pawtucket, R.I. “The best we can tell is that there isn’t an association. Once we took into account these other factors, high levels didn’t provide a benefit and low levels didn’t put you at risk.”
In the study, published online Oct. 26 in the American Journal of Clinical Nutrition, Eaton led an analysis of data from 2,429 postmenopausal women aged 50 to 79 who participated in the broad-based Women’s Health Initiative study, in which Eaton and many co-authors were investigators. They tracked blood levels of vitamin D in the women and their mortality over a 10-year period. They not only looked at death from all causes but also focused on cancer and cardiovascular disease.
In all, 225 of the women died, including 79 from cardiovascular disease and 62 from cancer.
Eaton said he expected to find some protective effect against such mortality from vitamin D, and at first glance — controlling only for age, ethnicity, and whether women took part in a calcium and vitamin D supplement trial — that’s what the data showed. But what was apparent in the data was that the women with the lowest levels of vitamin D also had a lot of other negative health indicators. The team therefore controlled for several more key health factors, such as smoking, history of cardiovascular disease, history of cancer, alcohol consumption, and waist circumference. The additional controls, especially waist circumference, which is a measure of abdominal obesity, eroded the statistical significance of vitamin D’s seemingly protective effects down to nothing.
The one exception was that women with thinner waistlines (less than 35 inches) and with the lowest vitamin D levels seemed to have a greater risk of “all-cause” mortality within the 10-year analysis period. That result, however, was right on the borderline of statistical significance.
“If you are thin, this data suggest that maybe low vitamin D levels are potentially harmful and you should talk to your doctor about what to do about them,” Eaton said.
Eaton said he and his co-authors can only speculate about why abdominal obesity was an especially important and powerful factor to control for in their analysis. In the study they note that abdominal obesity is associated with several negative health indicators that may overwhelm any modest benefit vitamin D might have. They also point out that fat tissue can store vitamin D, possibly meaning that women with larger waistlines are storing more of the vitamin than their blood serum levels alone would reveal.
More research into the connections between abdominal fat and the health effects of vitamin D could help resolve the question, Eaton said. He also said that a major new trial of vitamin D supplements and health called “VITAL” is getting underway and will likely inform the broader controversy about what vitamin D is good for.
For now, Eaton said, “there’s not enough evidence to do anything about our vitamin D levels if it’s not in regard to bone health.”