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home:pathogenesis:vitamind:longterm [05.26.2019] – [Immunosuppression and insufficient followup in vitamin D studies] sallieq | home:pathogenesis:vitamind:longterm [09.14.2022] (current) – external edit 127.0.0.1 | ||
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====== Immunosuppression and insufficient followup in vitamin D studies ====== | ====== Immunosuppression and insufficient followup in vitamin D studies ====== | ||
- | <relatedarticle> [[home: | + | <relatedarticles> [[home: |
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. | 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. | ||
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This practice is a mistake as it does not account for the long-term immunosuppressive effects of a 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 | + | For example, the U-shaped relationship between vitamin D levels and long-term outcome in large cohort |
===== Immunosuppression by high doses of vitamin D ===== | ===== Immunosuppression by high doses of vitamin D ===== | ||
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===== Short-term and long-term effects of vitamin D ===== | ===== Short-term and long-term effects of vitamin D ===== | ||
- | People who consume vitamin D through supplements or food are suppressing their innate immune response.(({{pubmed> | + | People who consume vitamin D through supplements or food are suppressing their innate immune response.(({{pmid> |
At a certain point, however, consuming the secosteroid starts to have an effect on those symptoms which researchers typically focus their attention. A person' | At a certain point, however, consuming the secosteroid starts to have an effect on those symptoms which researchers typically focus their attention. A person' | ||
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There are a number of studies, too many to review in the context of this article. Generally speaking, research noting a therapeutic effect of vitamin D tend to be short-term or in patients whose immune systems are yet to be suppressed. | There are a number of studies, too many to review in the context of this article. Generally speaking, research noting a therapeutic effect of vitamin D tend to be short-term or in patients whose immune systems are yet to be suppressed. | ||
- | A study out of Creighton University recently received attention, because the researchers found that vitamin D might lower the incidence of colorectal cancer.(({{pubmed> | + | A study out of Creighton University recently received attention, because the researchers found that vitamin D might lower the incidence of colorectal cancer.(({{pmid> |
- | Jacques Rossouw at the National Institutes of Health criticized the finding. His group conducted a similar study that tracked the effects of vitamin D in a larger cohort (36,282 vs. 1,179 subjects) over a longer period of time (seven vs. four years).(({{pubmed> | + | Jacques Rossouw at the National Institutes of Health criticized the finding. His group conducted a similar study that tracked the effects of vitamin D in a larger cohort (36,282 vs. 1,179 subjects) over a longer period of time (seven vs. four years).(({{pmid> |
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- | A 2000 study found that five patients confined to wheelchairs with severe weakness and fatigue were able to walk after supplementing with 300,000 IU’s of vitamin D, (150 times higher than the U.S. Institute of Medicine of the National Academy of Sciences' | + | A 2000 study found that five patients confined to wheelchairs with severe weakness and fatigue were able to walk after supplementing with 300,000 IU’s of vitamin D, (150 times higher than the U.S. Institute of Medicine of the National Academy of Sciences' |
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Those researchers, | Those researchers, | ||
- | One 2004 study found a clear association between high-dose vitamin D supplementation in infancy and an increased risk of atopy, allergic rhinitis, and asthma later in life.(({{pubmed> | + | One 2004 study found a clear association between high-dose vitamin D supplementation in infancy and an increased risk of atopy, allergic rhinitis, and asthma later in life.(({{pmid> |
- | According to another group of researchers, | + | According to another group of researchers, |
- | It is worth noting that studies of certain other classes of steroids, substances which are nearly [[home: | + | It is worth noting that studies of certain other classes of steroids, substances which are nearly [[home: |
- | A 2010 study found that Danish neonates with the highest measurable levels of 25-D had a two-fold elevated risk of developing schizoprhenia. The relationship was not explained by a wide range of potential confounding or interacting variables.(({{pubmed> | + | A 2010 study found that Danish neonates with the highest measurable levels of 25-D had a two-fold elevated risk of developing schizoprhenia. The relationship was not explained by a wide range of potential confounding or interacting variables.(({{pmid> |
- | Corticosteroids, | + | Corticosteroids, |
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- | [[https:// | + | view [[https:// |
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+ | ===== Furthermore ===== | ||
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+ | Two recent publications challenge the belief that 25(OH)D levels greater than 30 ng/mL are optimal for bone health. In a randomized, placebo-controlled trial, high-dose, once-yearly vitamin D therapy increased the incidence of fractures and falls. The second study reported that high-dose vitamin D did not reduce levels of parathyroid hormone or bone resorption among adults with 25(OH)D levels less than 32 ng/mL at baseline. It is time to question whether serum 25(OH)D levels of 30 ng/mL or greater are necessary for all individuals. (({{pmid> | ||
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+ | Blood vitamin D levels were associated with a risk of metabolic syndrome in cross-sectional studies but not in longitudinal studies. (({{pmid> | ||
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+ | Evidence does not support the use of vitamin D supplementation for the prevention of cancer, respiratory infections or rheumatoid arthritis. Similarly, evidence does not support vitamin D supplementation for the treatment of multiple sclerosis and rheumatoid arthritis or for improving depression/ | ||
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+ | New evidence indicates that both high and low 25(OH)D levels may be associated with increased health risks.(({{pmid> | ||
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+ | Despite a few hundred systematic reviews and meta-analyses, | ||
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{{tag> | {{tag> | ||
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===== Notes and comments ===== | ===== Notes and comments ===== | ||
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broken link// | broken link// | ||
- | ([[http:// | + | ([[https:// |
--- //Sallie Q 09.14.2016// | --- //Sallie Q 09.14.2016// | ||
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- | ===== References ===== | + | ===== References =====</ |