By Robert Verkerk PhD
Founder, executive and scientific director
Today marks the end of a two-month consultation window for the UK’s Scientific Committee on Nutrition (SACN) which has been tasked to review the recommendation for the amount of vitamin D. ANH-Intl has filed a submission which is deeply critical of the bottom line recommendation, which remains unchanged from previous reviews going back to 1991.
The 1991 recommendations, as conceded by the SACN in its draft report, “were based on prevention of rickets in children and osteomalacia in adults.” A rash of new and emerging data are now available. A large amount of this evidence points to clear benefits, without associated risk, being achieved when intakes increase above the paltry 10 micrograms a day (10 μg/d =400IU/day) that have been recommended to the British people for the last quarter of a century, at least when they are unable to be exposed sufficiently to summer sunshine.
The SACN recognises that one-fifth of Brits are deficient in vitamin D, even in terms of its own, very low, somewhat arbitrary blood serum 25-hydroxy-vitamin D (25 (OH) D) level of just 25 nmol/L . It also recognizes that the majority of some groups may have circulating levels beneath this level, including 79% of pregnant women.
It is astonishing, given these acknowledged figures, that the SACN has not been moved, in its draft report, to increase the recommended daily intake. This is particularly so in the face of the abundance of new evidence that has emerged over the last 26 years, since the COMA level was set in 1991.
The SACN has not only ignored key published studies, systematic reviews and meta-analyses, it has also discounted the threshold of adequacy for blood levels determined by the Institute of Medicine (IOM) in the USA, set at twice the UK value, namely 50 nmol/L of D 25(OH)D.
Download ANH-Intl consultation response on vitamin D
Among the main factors highlighted in our consultation response are:
- The SACN has cherry-picked data; numerous published studies have been omitted, many of them including dosages well above the 10 μg/d. One (omitted) study led by Johns Hopkins on pregnant and non-pregnant women in Bangladesh shows benefit of supplementation with levels 175 times greater than this (1750 μg/d = 70,000 IU/d), with no adverse effects.
- The SACN has not taken into account the problems with vitamin D intake studies; evaluating such studies are notoriously problematic because comparisons are made on group means as opposed to individuals, and many factors affect serum 25(OH)D status, including skin colour, age, the amount and quality of sun exposure and genetic polymorphisms affecting vitamin D binding protein (VBP) and vitamin D receptor (VDR).
- The SACN has misinterpreted available data on the effects of genetic polymorphisms on vitamin D requirement; The SACN recognized the importance of a wide range of polymorphisms affecting both the vitamin D binding protein and receptor, but failed to take account of it claiming it was unclear. While the polymorphisms are complex, widely distributed and require gene sequencing, there is copious evidence that those with certain polymorphisms require significantly larger amounts of vitamin D.
- The SACN has not sufficiently accounted for the effects of increased body weight and use of sunscreens; while the public, over the last quarter century, has been pushed to use more sunscreens or avoid sunlight exposure, it has, on average also become more overweight. Both factors are known to increase the vitamin D requirement.
- The SACN has ignored expert evidence; This evidence is recognised even by scientists at the US FDA and the College of Pharmacy and Nutrition, University of Saskatchewan, Canada, which points to a requirement for circulating levels at least three times greater than that proposed by the SACN.
- The SACN has ignored differences between vitamin D2 and D3; despite recognising a substantial body of evidence suggesting that vitamin D2 has an inferior capacity to raise serum levels as compared with vitamin D3, the SACN has not set different intakes for each vitamin form.
- The SACN has ignore emerging evidence for the role of elevated vitamin D status on reducing the risk of certain cancers; this is despite copious evidence to the contrary.
- The SACN has not proposed different recommendations for different racial groups/skin colours, despite extensive evidence that dark-skinned individuals have a much (typically two-fold) greater requirement
- The SACN has not considered that there are likely to be overlapping risks and benefits; this is a common feature of most, if not all, nutrients as shown in my review published in 2010.
- The policy recommendation does not reflect the best outcome scenario for public health; it appears that the SACN has worked to simply justify not changing the 26-year-old, now deeply outdated, recommended intake, in the face of chronic, gross vitamin deficiency being readily acknowledged.
Should there not be a significant revision to the recommendation on publication of the final version of the SACN report, we will be taking concerted action, about which we will be looking for vigorous support.
We will keep you updated on progress!
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