Monday, 27 July 2015

ClinicSpeak: vitamin D supplementation guidelines in the dog box

The long arm of industry and vitamin D supplements. #ClinicSpeak #MSBlog #MSResearch

"I have been making the claim that MSers should keep themselves vD replete and have recommended the Vitamin D Council's guidelines. The rationale for my advice is not because vD is a disease-modifying treatment - definitive evidence for the this is lacking - but to optimise bone health. The latter is not evidence-based, but comes from extrapolating results from studies that have been done in older women with osteopenia and osteoporosis. I am aware that there is a lack of evidence on this issue from the field of MS, which why Dr Ruth is currently preparing a post-doctoral fellowship application to address this issue."


"I am not a bone expert, which is why I defer to my esteemed colleagues in the field of vD biology and endocrinology for advice. This is why I was astounded when I read the following analysis over the weekend from last week's British Medical Journal that calls all the advice on vD and calcium supplementation in relation to bone health into question. Please note I have never recommended calcium supplements to MSers; there is no scientific rationale for this. Importantly, the authors' finger the influence of Industry in the setting of national and international guidelines in relation to vD and calcium supplements for the prevention of fractures. The esteemed Vitamin D Council is not exempt from the list (see table below)?"




"What should we do? I don't think I will change my advice just yet. I still think there is a strong argument from an evolutionary medicine perspective to be vD replete. However, to make the claim that this is for bone health reasons seems to be at odds with the evidence presented in this paper and recent meta-analyses. More importantly there is no evidence from studies done in MSers to support the bone health position. I will need to seek expert advice from my metabolic bone disease colleagues before coming back to you."




Excerpts


.... For many years, recommendations for prevention and treatment of osteoporosis have included increasing calcium intake (by diet or supplements) and use of vitamin D supplements. Since the average dietary calcium intake in most countries is much less than that recommended by guidelines, many older people (and MSers) are advised to take calcium supplements to prevent osteoporosis. The recommendations have been implemented successfully: over half of older Americans take calcium and vitamin D supplements, either prescribed or over the counter, and bone health is the most common specific motivation for use of nutritional supplements....

..... However, this behaviour does not reflect evidence that has emerged since 2002 that such supplements do not reduce the risk of fracture and may result in harm. Guideline bodies also continue to recommend calcium and vitamin D supplements. Here, we argue that change is made difficult by a complex web of interactions between industry, advocacy organisations, and academia.....

.... We conclude that increased calcium and vitamin D intake should not have been recommended for older adults living independently after 2007, a view consistent with the conclusion of the 2009 Cochrane review.18 However, many guidelines published since then recommend increasing calcium intake (to 1000-1200 mg/day) or use of vitamin D supplements (600-2000 IU/day) for managing osteoporosis. An exception is the United States Preventive Services Task Force, which recommended against calcium and vitamin D supplementation for primary fracture prevention in 2013....

.... Calcium and vitamin D supplements are very profitable. Global annual sales of calcium supplements in 2013 were about $6bn (£4bn; €5bn),w1 and those of vitamin D in the US in 2012 were $748m.w2 Companies that market foods rich in calcium or vitamin D also profit from the notion that these nutrients prevent osteoporosis. Notable examples include Fonterra, whose $NZ4bn (£2bn; €3bn; $3bn) annual sales in Asia include those of its calcium enriched milk products marketed for optimal bone health,w3 and Danone, whose annual sales of fresh dairy products are around €12bn (£9bn; $13bn), including products marketed as promoting bone health because they contain calcium and vitamin D....

..... Other industries benefit from enthusiasm for use of supplements for osteoporosis. Measurement of serum 25-hydroxyvitamin D has become widely used, benefiting both the manufacturers of assay kits and the laboratories that perform the tests. The commercial rewards are substantial— annual costs of vitamin D testing in Australia increased from $A1m (£500 000; €700 000; $800 000) in 2001 to $A96m in 2010.....

.... The US National Osteoporosis Foundation (NOF) and the Europe based International Osteoporosis Foundation (IOF) are highly influential advocacy organisations. Both state their aim as improving patient outcomes, but their objectivity may be compromised by the influence of a range of commercial sponsors, including companies that market supplements, dairy products, and nutrition related laboratory tests. In their drive to attract corporate sponsorship, the IOF and NOF emphasise their academic and scientific strengths and global influence, and offer the opportunity for corporate members to influence the strategic direction of the organisation at both formal and informal levels....

.... Other industry sponsored advocacy organisations have failed to acknowledge the unfavourable evidence. The news section of the website of the Vitamin D Council does not mention the recent meta-analyses of randomised trials that reported no health benefits of vitamin D supplements, while less rigorous research findings that encourage vitamin D testing and use are enthusiastically endorsed....

.... Setting aside finances, academic leaders may also have academic conflicts of interest. For example, their career development may be enhanced by the persistence of beliefs that nutritional supplements benefit the skeleton. Such conflicts of interest may have influenced the Endocrine Society’s endorsement of widespread moderate dose vitamin D supplementation in contrast with the Institute of Medicine (IOM), which recommended low level supplementation for older adults, and the Preventive Services Task Force, which advised against vitamin D supplementation......

...... The interactions among the nutrition industry, advocacy organisations, and academia are complex. Each party benefits. Industry gains scientific credibility, which protects or enhances sales of its products, and indirect marketing through advocacy groups. Advocacy organisations and specialist societies gain funds to support their existence. Academics gain by maintenance of their status and by obtaining access to research funds and career enhancing publications and presentations. The party that may lose, and be harmed, is the public. Failure to reverse inappropriate practice leads to overtreatment, systematic waste of healthcare resources, unnecessary costs for patients, and missed opportunities for application of interventions with proved efficacy. Ultimately, the cost is erosion of trust in the medical system......

CoI: none

7 comments:

  1. I never quite understood why sell remedies and supplements the base of Vitamin D and Calcium together. If they had really concerned about bone health of people who do lobby on top of vitamin K2 supplements, or something of vitamin K2 with D3 (although some studies have pointed out that the D association with K2 did not improve bone turnover), and not Calcium ...

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  2. You said last week you were to hinking of doing a series on bone health. Not a minute too soon! I was diagnosed with osteoporosis a day later! I'm not even menopausal, on the high side of normal weight, don't smoke, never had bulimia, etc. And I'm not inactive or disabled by my MS. In fact, I've been thinking of myself as healthy for an MSer.

    What I learned, which isn't widely known, is that some research has found that at diagnosis--before disability, before steroids, before menopause, most MSers already have more bone thinning than healthy controls.

    Well, I'm off to pick a new nasty drug to add to my regime. I hope you do your series soon.

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  3. It has been shown by two independent studies that the RDA for vitamin d as set by the IOM is wrong and was miscalculated. Therefore any studies where the dose regime was based on this RDA are flawed and any meta analysis is also flawed. The meta analysis should be redone only using trials which match the corrected RDA and lets see what that tells us. The RDA appears to be out by 10 times.

    A Statistical Error in the Estimation of the Recommended Dietary Allowance for Vitamin D
    Paul J. Veugelers* and John Paul Ekwaru
    Nutrients. 2014 Oct; 6(10): 4472–4475.
    Published online 2014 Oct 20. doi: 10.3390/nu6104472

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    Replies
    1. Ten times higher than it should be? Or 10 times lower?

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    2. Underestimated by quite a lot. This is for Vitamin D not calcium. Quite worrying that Vitamin D and calcium are so often conflated.

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    3. From the paper:
      "This regression line revealed that 600 IU of vitamin D per day achieves that 97.5% of individuals will have serum 25(OH)D values above 26.8 nmol/L rather than above 50 nmol/L which is currently assumed. It also estimated that 8895 IU of vitamin D per day may be needed to accomplish that 97.5% of individuals achieve serum 25(OH)D values of 50 nmol/L or more. As this dose is far beyond the range of studied doses, caution is warranted when interpreting this estimate. Regardless, the very high estimate illustrates that the dose is well in excess of the current RDA of 600 IU per day and the tolerable upper intake of 4000 IU per day"

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    4. The paper above used the original data used by the IOM, and recalculated the RDA without the mistake in the calculation. The work has been repeated with a newer data set by Creighton University and they got an RDA of 7000IU a day. 50nmol/L was chosen as a minimum safe level not a maximum based and it was thought to be the minimum to maintain bone health. With a correct blood vitamin d you will not need all that extra calcium and without the vitamin d your body can do very little with the calcium, it will go in one end and out the other. The other give away that the RDA for adults is wrong is the RDA for a new born is 400IU a day, while a full sized adult is 600IU (200IU in the UK).

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