Vitamin D ineffective for vascular health and fatigue in CFS

[MeSci]

http://www.nmcd-journal.com/article/S0939-4753(14)00315-9/abstract?cc=y

Effect of intermittent vitamin D3 on vascular function and symptoms in chronic fatigue syndrome – A randomised controlled trial

M.D. Witham, Dr F. Adams,S. McSwiggan,G. Kennedy,G. Kabir,J.J.F. Belch,F. Khan
Medical Research Institute, University of Dundee, Ninewells Hospital, Dundee DD1 9SY, Scotland
Received: August 2, 2014; Received in revised form: October 1, 2014; Accepted: October 14, 2014; Published Online: October 22, 2014

Highlights

• We randomised 50 patients with CFS/ME to receive six months of intermittent high-dose vitamin D or placebo.
• Vitamin D did not improve pulse-wave velocity or flow-mediated dilatation of the brachial artery compared to placebo.
• Vitamin D did not improve markers of oxidative stress or inflammation compared to placebo.
• Vitamin D did not improve symptoms of fatigue compared to placebo.

Abstract
Background and aims
Low 25-hydroxyvitamin D levels are common in patients with chronic fatigue syndrome; such patients also manifest impaired vascular health. We tested whether high-dose intermittent oral vitamin D therapy improved markers of vascular health and fatigue in patients with chronic fatigue syndrome.

Methods and Results
Parallel-group, double-blind, randomised placebo-controlled trial. Patients with chronic fatigue syndrome according to the Fukuda (1994) and Canadian (2003) criteria were randomised to receive 100,000 units oral vitamin D3 or matching placebo every 2 months for 6 months. The primary outcome was arterial stiffness measured using carotid-femoral pulse wave velocity at 6 months. Secondary outcomes included flow-mediated dilatation of the brachial artery, blood pressure, cholesterol, insulin resistance, markers of inflammation and oxidative stress, and the Piper Fatigue scale.

50 participants were randomised; mean age 49 (SD 13) years, mean baseline pulse wave velocity 7.8 m/s (SD 2.3), mean baseline office blood pressure 128/78 (18/12) mmHg and mean baseline 25-hydroxyvitamin D level 46 (18) nmol/L. 25-hydroxyvitamin D levels increased by 22nmol/L at 6 months in the treatment group relative to placebo. There was no effect of treatment on pulse wave velocity at 6 months (adjusted treatment effect 0.0 m/s; 95% CI -0.6 to 0.6; p=0.93). No improvement was seen in other vascular and metabolic outcomes, or in the Piper Fatigue scale at 6 months (adjusted treatment effect 0.2 points; 95% CI -0.8 to 1.2; p=0.73).

Conclusion
High-dose oral vitamin D3 did not improve markers of vascular health or fatigue in patients with chronic fatigue syndrome.

Trial registration
www.controlled-trials.com, ISRCTN59927814.

 

[Dolphin]

Participants took capsules in front of researchers to ensure adherence.

 

[Dolphin]

This trial has some interesting data which the authors don't really comment on: all the test results and how they might compare with normals. It would be interesting to know the means, SDs, etc. for the test results for healthies to see what of abnormalities showed up (including things that have been measured before to see whether or not abnormal results were replicated).

 

[MeSci]

I was struck by some details in the full text that may suggest that the sample wasn't typical. For example, the average blood pressure was quite normal (124/76 at baseline), whereas I had gained an impression on PR that blood pressure was commonly low. My poll also shows this.

The participants also had a high average BMI - close to obese, in fact (28.8). I know that many of us gain a lot of weight, but a lot are underweight, and this doesn't seem to be reflected in the study sample.

 

[Dolphin]

I was struck by some details in the full text that may suggest that the sample wasn't typical. For example, the average blood pressure was quite normal (124/76 at baseline), whereas I had gained an impression on PR that blood pressure was commonly low. My poll also shows this.

The participants also had a high average BMI - close to obese, in fact (28.8). I know that many of us gain a lot of weight, but a lot are underweight, and this doesn't seem to be reflected in the study sample.

The sample was older than nearly all samples I've seen (mean age 49.4). I think that would on average increase the BMI and the blood pressure. The BMI is probably similar to the BMI of people of that age in Scotland/the UK. Given more people with the illness put on weight than lose it, it doesn't seem particularly unusual to me.

 

[NilaJones]

Getting my vitamin D levels up to 90-100 helped me a lot with fatigue. I have no known vascular problems.

Then I took too much vitamin D, got high blood calcium, was nauseous and couldn't eat for two weeks. That part I do not recommend.

 

[Anika]

I'm confused about the group, too, reading only the abstract. It says the 50 randomised participants had mean baseline vitamin D of 46 nmol/L, which increased by 22 nmol/L at 6 months "relative to placebo," which seems an odd way of putting it. My understanding is 46 is within normal limits for Vitamin D - not even low normal, though one could question what optimal level is.

So, though they say that low vitamin D levels are common in CFS, it doesn't sound like their treatment group had low vitamin D levels to begin with unless I'm misreading the Methods. Did they clearly have impaired vascular health to begin with?

Am I missing something about the point of this exercise that is clear from the full text?.

 

[NilaJones]

I'm confused about the group, too, reading only the abstract. It says the 50 randomised participants had mean baseline vitamin D of 46 nmol/L, which increased by 22 nmol/L at 6 months "relative to placebo," which seems an odd way of putting it. My understanding is 46 is within normal limits for Vitamin D - not even low normal, though one could question what optimal level is.

So, though they say that low vitamin D levels are common in CFS, it doesn't sound like their treatment group had low vitamin D levels to begin with unless I'm misreading the Methods. Did they clearly have impaired vascular health to begin with?

Am I missing something about the point of this exercise that is clear from the full text?.

My doc says that 50 used to be considered optimal but, based on new research, 100 is now considered the healthy level. So, 46 would be dangerously low.

I came across something the other day, though, which said that this is only true for people from light-skinned ethnic groups. People from darker-skinned groups may have optimal levels that are much lower -- around 50, IIRC.

I assume this is because light skin evolved in northern areas where it's necessary to store up enough D in the summer to last all winter. My ancestors are from Ireland, England, and Germany (which is not that far north but I hear it has no sun.) People like me tolerate, and even function optimally, with high levels that would be dangerous for normal people .

 

[Anika]

Thanks, I know that there is some discussion about optimal levels and different viewpoints.
I managed to get my Vit D up to 50 very slowly. Last time I discussed increasing my D with my doctor, she expressed concern about not getting them too high, which sort of surprised me. She seemed ok with something in the 60s, but I'm not really sure what her reasons were. I've got the fair skin too. Maybe I can discuss this further at next visit.