July 21, 2016

expert reaction to new SACN recommendations on vitamin D

The Scientific Advisory Committee on Nutrition (SACN) has recommended that everyone over one year of age should consume 10 micrograms of vitamin D each day in order to protect musculoskeletal health.

Prof. Peter Selby, Consultant Physician and Honorary Clinical Professor of Metabolic Bone Disease, University of Manchester, said:

“I very much welcome the SACN recommendations and the associated guidance from PHE.  It puts the evidence regarding the effects of vitamin deficiency into a UK context and demonstrates the benefits for bone health that could be achieved by a relatively simple supplementation programme. In particular it dispels any doubt of the place of vitamin D in the maintenance of bone health and should ensure that all people will now be encouraged to receive vitamin D to reduce their risk of bone disease and fracture.”

Prof. Zulf Mughal, Consultant in Paediatric Bone Disorders and Honorary Clinical Professor of Child Health, Royal Manchester Children’s Hospital, said:

Is this guidance based on good quality research?

“It is my opinion that the SACN committee have looked at available evidence to make reconditions that apply to 97.5% of the UK population. Hopefully future reviews will look at vitamin D needs of dark skinned sub-populations.

Are the conclusions backed up by solid data?

“In my opinion, yes.

Do you think the advice is sensible?

“Yes.  However, it is disappointing that there are no clear guidance on how much time people of different skin tones need to spend outdoors, in order to maintain adequate body stores of vitamin D during Summer & Early Autumn. I suspect that this is due to lack of data from studies and trials that were available to the committee members.

“As the sun’s ultraviolet B radiation (which acts on the vitamin D precursor in skin to produce vitamin D) does not reach ground level between March to September in the majority of the UK, advice about the need for supplementation (10 micrograms or 400 i.u./day) is very sensible.

Are there important limitations to be aware of?

“Not major ones based on my cursory reading of the report.

“I am disappointed that 10 micrograms or 400 i.u. of vitamin D per day was not recommended from birth as in other countries, e.g. the USA.

What are the implications in the real world?

“While advice in SACN report is sensible, it will only help to prevent cases of rickets, dilated cardiomyopathy of the heart, severe muscle weakness, propensity to fall and fractures, if the advice is implemented. Will the NHS fund provision of free vitamin D, as per the SCAN guidance, for the whole of the UK population, or for sub-groups who are most at risk, e.g. dark skinned individuals who wear concealing clothing for religious or cultural reasons?

“I have not read the full report in detail and so I am not sure if SACN has undertaken health economic modelling to look at cost-benefits of providing free vitamin D supplements for the whole population or vulnerable sub-groups.

What about the guidance for breastfed and bottle fed babies?

“It is well known that infants who are breast fed and not provided with vitamin D supplements are at increased risk of developing florid rickets [Mughal et al. BMJ. 1999 Jan 2; 318(7175): 39-40]. So I am delighted that GPs, Health Visitors, and paediatricians will be able to recommend (and ideally providing vitamin D free of charge) that breastfed infants ought to take vitamin D (I wish it was 10 micrograms or 400 i.u. per day) from birth.

“In my opinion this advice, if universally implemented, may help to reduce the number of cases of children with rickets and potentially life-threatening dilated cardiomyopathy. I have seen two infants die of dilated cardiomyopathy due to severe vitamin D deficiency.

What do you think about the advice that we all take a daily supplement during winter months?

“As mentioned above, in my opinion this is very sensible advice.”

Prof. Julia Newton-Bishop, Professor of Dermatology, Leeds Institute of Cancer and Pathology, University of Leeds, said:

“The report published by the SACN is a detailed and exceptionally well researched report addressing the controversial issue of vitamin D.

“As a melanoma expert I am concerned that this skin cancer is becoming increasingly common, and as the environmental exposure which causes melanoma is holiday sun exposure, I am keen to limit intense exposure in sunny weather in the pale skinned (which describes a large proportion of the UK population), but our own research suggests that this would reduce vitamin D levels if accepted.

“The SACN has described data which suggest that having blood levels of vitamin D of less than 25nmol/l is harmful, and it is evident that levels below 25nmol/L occur not infrequently in the UK. I am therefore concerned that advice given to reduce the risk of melanoma does not increase the likelihood of vitamin D deficiency.

“The data suggest that the elderly are also at especial risk of vitamin D deficiency and people with darker skin, so I therefore welcome the advice from the SACN that the whole UK population overall should aim for a modest intake of vitamin D (400IU per day). I think this is consistent with the data and indeed with my experience in clinic. I believe moreover that this advice to take modest supplements rather than higher doses is very sensible as we don’t really know if harmful effects might result from higher doses.”

Prof. David Richardson, Founder and Director DPR Nutrition Limited (a company that provides specialist consultancy on food science and nutrition), and Visiting Professor, School of Chemistry, Food & Pharmacy, University of Reading, said:

“At the plenary meeting of the European Food Safety Authority Panel on Dietetic Products, Nutrition and Allergies (NDA Panel) on 28–30th June 2016, the Panel adopted its Dietary Reference Value (DRV) scientific opinion on vitamin D. This action followed a public consultation, which attracted comments from 67 interested parties across the EU.

“There is a great deal of consistency in the two reports of the scientific data by EFSA and SACN. However, the EFSA NDA Panel concluded that a serum 25(OH)D concentration of 50 nmol/L is a suitable target value to set the DRVs for vitamin D for all age and sex groups (healthy adults, infants, children, pregnant and lactating women). The EFSA Panel considered that there is evidence for an increased risk of adverse musculoskeletal health outcomes at serum 25(OH)D concentrations below 50 nmol/L. In contrast, the SACN concluded that the evidence suggests the risk of poor musculoskeletal health is increased at serum 25(OH)D concentrations below 25 nmol/L.

“The resultant DRVs from EFSA and SACN are therefore 15 µg/day and 10 µg/day for everyone over one year of age. The choice of biomarker of vitamin D status is the same in both reports, and it is true that the cut-off points used to define deficiency or low status are controversial. Nevertheless, the different conclusions of these two authoritative reports are likely to confuse consumers about the amounts of vitamin D needed for health.

“The SACN report states that the Reference Nutrient Intake of 10 µg/day includes pregnant and lactating women. A key question is whether this is sufficient to ensure an adequate amount in the milk of nursing mothers.

“The National Diet and Nutrition Survey (NDNS) data demonstrate that during the first year of life and infancy, large numbers of breastfed infants are not meeting the requirements for vitamin D. If the SACN’s recommendation is for 10 µg/day for nursing mothers and 8.5–10 µg/day for babies, there appears to be a disconnect between the physiological facts and the proposed recommendations which should be at least 15 microgram/day for mother and baby. The SACN needs to reconsider the appropriateness of its recommendation for a level of 10 µg/day for pregnant and lactating women.

“Furthermore, the SACN’s proposal for a range of values from 8.5 to 10 µg/day for all babies from birth up to one year is likely to create confusion among doctors, healthcare professionals and parents alike.  EFSA sets an Acceptable Intake at 10 µg/day for infants aged 7–11 months.

“In addition, the SACN report does not draw sufficient attention to frail, older people with the highest likelihood of deficiency. The recommendation is too vague for elderly institutionalised individuals and for the use of targeted supplementation to reduce risk of falls and bone fractures.

“Because dietary sources of vitamin D are scarce, the nutrient being found in only a few natural foods (fatty fish, liver, milk, eggs and fat spreads with added vitamin D are the main sources) it is not so easy to obtain the amounts necessary for good health. Similarly, indoor lifestyles encouraged by television, computers etc., as well as the use of sun screens have significantly reduced the synthesis of vitamin D in the skin.

“The evidence from the NDNS shows that large numbers of the population have suboptimal levels of vitamin D 25(OH)D even in the summer.

“The advice from Public Health England to take a daily vitamin D food supplement is to be welcomed. The cost of improving vitamin D levels in the UK population through the use of food supplements is small compared to the likely gains to public health and healthcare costs.”

Dr Benjamin Jacobs, Consultant Paediatrician, Royal National Orthopaedic Hospital, said:

“This SACN report is a major step forwards. It will help prevent rickets and other significant medical problems for babies and children in the UK.

“For the first time the UK authorities recommend starting Vitamin D for babies soon after birth. The previous advice, to wait until 6 months of age for most children, was wrong. Paediatricians like me see babies younger than 6 months with major medical problems including hypocalcaemic convulsions and rickets that would be prevented if they had Vitamin D. The Royal College of Paediatrics and Child Health has campaigned for the last 5 years to bring the starting age down to ‘soon after birth’ and is happy to see that recommendation has now been accepted.

“In my view the advice should go further though. The doses recommended could be higher, and it would have been simpler to suggest that all children get the same dose. The variable dose “8.5-10 micrograms until 1 year of age” may lead to confusion among parents and health professionals.

“Also the advice for pregnant women to take just 10 micrograms of Vitamin D is too conservative. Recently the MAVIDOS study¹ of more than a thousand pregnant women showed strong evidence that we can improve the health of babies bones by giving mothers a daily dose of 40 micrograms.”

1: ‘Maternal gestational vitamin D supplementation and offspring bone health (MAVIDOS): a multicentre, double-blind, randomised placebo-controlled trial’ by Cyrus Cooper et al., The Lancet Diabetes & Endocrinology, March 2016 

Prof. Adam Balen, Chair of the British Fertility Society, said:

“There has been increasing information in recent years about the important role of vitamin D for healthy reproduction. The new guidance from PHE indicates that the general UK population (aged 4y and above) require a daily intake 10 μg/d (400 IU/d) and this includes pregnant and lactating women. It is therefore very important that women attending fertility clinics should be advised to take preconception vitamin D supplements alongside folic acid. Consideration should also be taken for the formal measurement of vitamin D levels, especially in high risk groups.”

Prof. Susan Fairweather-Tait, Professor of Mineral Metabolism, University of East Anglia (UEA), said:

“SACN have based the requirements on a target 25OHD concentration (25-hydroxy-vitamin D, one form of vitamin D found in plasma) of 25 mmol/L, the level below which there is an increased risk of adverse effects on bone health. The intake values were derived from data describing the relationship between intake and blood levels in the winter, when there is no contribution made by UV exposure.

“They employed a more conservative approach than EFSA, who selected a target 25OHD concentration of 50 mmol/L, and it is possible in the future that evidence for a dose-related effect of vitamin D on other health endpoints will emerge and the Dietary Reference Values may need to be revised upwards.

“For individuals who don’t consume high amounts of the few foods that are naturally rich in vitamin D, and in the absence of a comprehensive UK programme of food fortification, supplements may be needed in the winter months.

“Foods naturally rich in vitamin D include oily fish (e.g. tuna, mackerel, salmon, pilchards, kippers, sardines), egg yolk, cod liver oil, and smaller amounts are found in liver, meat and milk. Some foods are voluntarily fortified with vitamin D, such as breakfast cereals, fat spreads and yoghurts.”

‘Vitamin D and Health’ is published by the Scientific Advisory Committee on Nutrition (SACN) on Thursday 21 July 2016. 

Declared interests

Prof. Zulf Mughal: “I have received honoraria from Infant Formula companies & Pharma companies for unbiased educational talks.”

Prof. David Richardson: “I provide consultancies to the food and food supplement industries, NGOs, international organisations etc. and I have done work for the UK FSA and European Commission.  Visiting Professor, School of Chemistry, Food & Pharmacy, University of Reading; Scientific Adviser to the Council for Responsible Nutrition UK; Former member of the Committee on Medical Aspects of Food Policy (COMA).”

Dr Benjamin Jacobs: “Research grants and honoraria from Consillient Health, Danone, Kellogg’s, BetterYou, Internis and Alexion.”

Prof. Adam Balen: “No declarations.”

Prof. Susan Fairweather-Tait: “I am an appointed expert with EFSA and the NDA Panel has recently published an opinion on vitamin D dietary reference values.”

No others received.