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home:pathogenesis:vitamind:correlation [02.25.2017] – [Mistaking correlation for causation in vitamin D studies] added ref. sallieq | home:pathogenesis:vitamind:correlation [09.14.2022] (current) – external edit 127.0.0.1 | ||
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- | Many vitamin D studies suffer from methodological errors including [[home: | + | Many vitamin D studies suffer from methodological errors including [[home: |
- | 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.(({{pubmed> | + | 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.(({{pmid> |
In fact, molecular science has revealed that the levels of the vitamin D metabolites through a [[home: | In fact, molecular science has revealed that the levels of the vitamin D metabolites through a [[home: | ||
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< | < | ||
- | //**Dr. Ruth McQuillan**, | + | //**Dr. Ruth McQuillan**, |
[{{ : | [{{ : | ||
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===== Causation is not self-evident ===== | ===== Causation is not self-evident ===== | ||
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There are a number of examples where low levels of a substance are known to be associated with but not cause disease. | There are a number of examples where low levels of a substance are known to be associated with but not cause disease. | ||
- | * **Folic acid** – Low levels of folic acid often lead to an increase in the amino acid homocysteine – a compound that at high levels has been linked to increased incidence of cardiovascular disease (CVD). Yet, extensive studies have revealed that giving patients with CVD folic acid supplements does not lower levels of homocysteine, | + | * **Folic acid** – Low levels of folic acid often lead to an increase in the amino acid homocysteine – a compound that at high levels has been linked to increased incidence of cardiovascular disease (CVD). Yet, extensive studies have revealed that giving patients with CVD folic acid supplements does not lower levels of homocysteine, |
- | * **Estradiol** – In a recent study, both low and high serum levels of estradiol (a type of sex hormone), compared with mid-range levels, are significantly and independently associated with increased all-cause mortality in men with chronic systolic heart failure.(({{pubmed> | + | * **Estradiol** – In a recent study, both low and high serum levels of estradiol (a type of sex hormone), compared with mid-range levels, are significantly and independently associated with increased all-cause mortality in men with chronic systolic heart failure.(({{pmid> |
< | < | ||
- | //**Vasan Ramachandran, | + | //**Vasan Ramachandran, |
- | Even among those who support widespread supplementation with vitamin D on the basis of the " | + | Even among those who support widespread supplementation with vitamin D on the basis of the " |
- | Causation should never be assumed to be self-evident.(({{pubmed> | + | Causation should never be assumed to be self-evident.(({{pmid> |
< | < | ||
- | //**L.R. Karhausen**// | + | //**L.R. Karhausen**// |
- | In the absence of an understanding grounded in molecular and clinical evidence, the comprehension of how vitamin D affects disease becomes "black box epidemiology." | + | In the absence of an understanding grounded in molecular and clinical evidence, the comprehension of how vitamin D affects disease becomes "black box epidemiology." |
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* sunshine exposure causes teenage pregnancy | * sunshine exposure causes teenage pregnancy | ||
- | {{: | + | {{: |
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The practice of failing to measure 1,25-D is pervasive: the NIH continues to accept studies and a number of journals continue to publish papers. | The practice of failing to measure 1,25-D is pervasive: the NIH continues to accept studies and a number of journals continue to publish papers. | ||
- | Further, mistaking 1,25-D for other forms is more common than one might think. A 2011 study actually gave " | + | Further, mistaking 1,25-D for other forms is more common than one might think. A 2011 study actually gave " |
One of the reasons that 1,25-D isn't measured may be that it is harder to test. But another reason may be that a high 1,25-D is inconsistent with reports of vitamin D " | One of the reasons that 1,25-D isn't measured may be that it is harder to test. But another reason may be that a high 1,25-D is inconsistent with reports of vitamin D " | ||
- | {{tag>Study_Design}} | + | < |
+ | “Nowadays it is virtually impossible to buy milk in the US that has not been laced (‘fortified’) with vitamin D. The amounts added, and the content, have been subject to dubious control, and a number of fatalities have occurred due to Vitamin D poisoning from milk.” | ||
+ | “The mis-labeling of this compound as a vitamin is regrettable, | ||
+ | {{tag> | ||
+ | [[https:// | ||
+ | ]] | ||
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+ | < | ||
===== Notes and comments ===== | ===== Notes and comments ===== | ||
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+ | broken link [[https:// | ||
* Jigsaw suggests: | * Jigsaw suggests: | ||
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Last edited on 18 Jul 2013 04:46 pm by Jigsaw | Last edited on 18 Jul 2013 04:46 pm by Jigsaw | ||
- | ===== References ===== | + | ===== References =====</ |