Monday, 8 October 2012

Vitamin D deficiency and Chronic Fatigue Syndrome

Vitamin D3 @ Wikipedia 
I have no hesitation in admitting to being more than a little bit "obsessive" about my data capture and the volumes of lovely, yummy science-y research alerts it produces. Indeed quite a bit of said research ends up as fodder for this and its sister blogs but most in the Twitter onslaught which my poor followers have to endure. Yes, I am probably addicted to information (but better this than other vices).

One of my alerts is based on the various collected works being done on everyone's favourite sunshine vitamin (or rather hormone), vitamin D. I've talked about vitamin D a few times on this blog, most recently in this post on autism and a possible relationship with the stuff. Gone it seems are the days when vitamin D was solely the reserve of the English disease, to be replaced by something altogether more wide-ranging bearing in mind the old 'correlation does not equal causation' sentiment (and the subsequent backlash).

A recent alert on vitamin D caught my attention on some findings tied into another non-autism topic of interest, chronic fatigue syndrome (CFS). I was interested in this news piece for a few reasons: (a) CFS is just getting over the whole XMRV de-discovery story (although I hasten to add with a few potential spanners in the works still remaining) and (b) CFS represents another one of those conditions of uncertain origin and pathology (indeed perhaps in an even worse state of 'not knowing' than conditions like autism).

Reading the story of the study on CFS-vitamin D however, my brow began to furrow following the realisation that despite being dated 30 September 2012, the article in question actually refers to this paper by Berkovitz and colleagues* published in July 2009. I'm beginning to get mightily displeased when this happens; news pieces talking about 'new' research despite the fact that being over 3 years old doesn't mean new; in the same way that a toddler is not a newborn.

Leave it Paul, leave it...

OK, since I found the Berkovitz paper, which is still very interesting, I am going to stick with it for now.

  • This was a retrospective study looking at serum 25-OH vitamin D levels among 221 participants diagnosed with CFS in the UK. Comparison was made to some population data from a longitudinal study of women in the UK .
  • Results: "25-OH vitamin D levels are moderately to severely suboptimal in CFS patients" and were significantly different when compared with the population data comparators.

There's nothing too earth-shattering about this study and its results given that sunshine is a big contributor to maintaining adequate levels of vitamin D and depending on the severity of the presented CFS, I would imagine getting outside (every day) is probably not going to be so easy for many. That and some interesting suggestions of a link with things like light sensitivity (something we also found in our very brief foray into CFS research) in cases of CFS probably not predisposing some people to get outside in direct sunlight for too long.

This is not the first time that vitamin D crops up in the research literature on CFS. Antiel and colleagues** described hypovitaminosis D (deficiency) as being present in about a fifth of their cohort of adolescents with chronic fatigue and orthostatic intolerance (standing up leads to symptoms). Taking into account the other variables Antiel reported such as iron insufficiency and deficiency, one has to be careful however not to necessarily link lower levels of vitamin D to symptoms over and above it just being an artifact from other issues.

But that's not say other authors have not put forward a more direct relationship between vitamin D issues and CFS as per this speculative article by Hoeck & Pall*** on vitamin D and its potential anti-inflammatory effects. I'm strangely taken to their suggestion that vitamin D might interfere with "chronic NF-κB activation" given the rise and rise of inflammation being seemingly associated with lots of conditions including CFS.

I'd like to think that vitamin D is an area worthy of greater consideration in cases of CFS (and ME, myalgic encephalomyelitis) added to other areas including mitchondrial dysfunction and the whole search for a biomarker thing (met-ab-o-lomics). Bearing in mind previous indications of severe vitamin D deficiency being tied into cases of persistent musculoskeletal pain**** and the whole osteomalacia thing, there is some potentially important overlap present.

Whether or not there is some influence from underlying issues with absorption of vitamins and minerals as per the 'leaky gut' suggestions might also be a question to ask. By saying this I'm also conscious of the fact that a vitamin D inadequacy/deficiency seems to be linked to just about everything nowadays; from heart disease to issues with pediatric neurodevelopment, from tuberculosis to even baldness. Just add CFS to the list, eh? Of course, I've not even touched upon vitamin D receptor functioning and whether this might also be something to look at with CFS in mind*****.

Finally I suppose if anything else, the bank of blood samples that now resides with virus-hunter Ian Lipkin post-XMRV study might serve as quite a nice study population to further add to this area of investigation.So once again I await further investigation in this area.

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* Berkovitz S. et al. Serum 25-hydroxy vitamin D levels in chronic fatigue syndrome: a retrospective survey. Int J Vitam Nutr Res. 2009; 79: 250-254.

** Antiel RM. et al. Iron insufficiency and hypovitaminosis D in adolescents with chronic fatigue and orthostatic intolerance. South Med J. 2011; 104: 609-11.

*** Hoeck AD. & Pall ML. Will vitamin D supplementation ameliorate diseases characterized by chronic inflammation and fatigue? Med Hypotheses. 2011; 76: 208-213.

**** Plotnikoff GA. & Quigley JM. Prevalence of severe hypovitaminosis D in patients with persistent, nonspecific musculoskeletal pain. Mayo Clin Proc. 2003; 78: 1463-1470.

***** Blaney GP. et al. Vitamin D metabolites as clinical markers in autoimmune and chronic disease. Ann N Y Acad Sci. 2009; 1173: 384-390.

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ResearchBlogging.org Berkovitz S, Ambler G, Jenkins M, & Thurgood S (2009). Serum 25-hydroxy vitamin D levels in chronic fatigue syndrome: a retrospective survey. International journal for vitamin and nutrition research. Internationale Zeitschrift fur Vitamin- und Ernahrungsforschung. Journal international de vitaminologie et de nutrition, 79 (4), 250-4 PMID: 20209476