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Lesley Riddoch: Sunshine vitamin in short supply

Scots cant depend on 15 minute sof vitamin D a day in summer. Picture: David Moir

Scots cant depend on 15 minute sof vitamin D a day in summer. Picture: David Moir

THOUGH not medically proven, it looks likely that lack of vitamin D is adding to Scots’ ill health, writes Lesley Riddoch

IS VITAMIN D deficiency behind Scotland’s status as “sick man of Europe”? There’s a strong but medically unproven correlation between our cloudy climate, lack of vitamin D and the highest incidence of multiple sclerosis on the planet.

But other evidence about the importance of our missing sunshine vitamin is also mounting up. Researchers at Edinburgh University say the number of children diagnosed with bowel disease in Scotland has risen by 75 per cent in a decade. Study leader Professor David Wilson thinks the rapid rise could be due to poor diet and low vitamin D levels.

According to a 2010 British Medical Journal published study of half a million people in ten west European countries, patients on the highest levels of vitamin D supplementation had a 40 per cent lower risk of colorectal cancer than those on the lowest. John Hopkins University academics agree. “Adequate levels of vitamin D reduce the risk of developing prostate cancer and may help suppress the growth and spread of prostate cancer cells in men who already have it.”

A randomised trial reported in the 2010 American Journal of Clinical Nutrition found Vitamin D supplementation produced an 83 per cent reduction in asthma attacks.

Meanwhile, vitamin D has been found to work more like a hormone which regulates the immune system, DNA repair and insulin production – there is a vitamin D receptor in every organ of the body.

Charities like the Cancer Recovery Foundation are convinced. “Current recommended daily allowances in the UK do not reflect the new understanding we have that vitamin D is needed by a number of organs, as well as to keep our teeth and bones healthy. So, we recommend you take 2,000 IU (international units) every day if you are healthy, and 5,000 IU if you are living with cancer.”

Arthritis Research UK say: “Our advice is to step outside to get vitamin D. From June to August, just 15 minutes is generally enough.”

That would be fine if Scotland had regular summer sunshine. As current weather demonstrates, it doesn’t.

Britain’s chief medical officers sent a joint letter to GPs this year conceding that “the National Diet and Nutrition Survey demonstrates up to a quarter of people in the UK have low levels of vitamin D in their blood”.

Experts think that’s an underestimate – Simon Pearce, Professor of Endocrinology at Newcastle University says: “More than 50 per cent of the adult population has insufficient levels of vitamin D and 16 per cent have severe deficiency during winter and spring. The highest rates (of vitamin D deficiency) are in Scotland, Northern England and Northern Ireland.”

An Edinburgh University survey of 2,230 participants aged 21-80, published last summer, found 84 per cent of Scots sampled were vitamin D-deficient using the “adequate level” of 50 nmol/l accepted by the World Health Organisation and US Institute of Medicine.

How can there be such a discrepancy between “official” and research findings? Firstly, the Scientific Advisory Committee on Nutrition (SACN) sets the “adequate level” of Vitamin D in the blood at 25 nmol/l – that’s just half the WHO’s “adequate level” and a quarter of the level recommended by many experts.

Secondly, official figures cover the whole of the UK. Edinburgh University has focused exclusively on the Scots whose northerly latitude, indoor-society, computer-based leisure lives and oily fish-free diet may be contributing to the lowest levels of vitamin D in Europe.

But the biggest problem for Scots is our cloudy summer climate which means Scots struggle to absorb enough vitamin D through exposed skin to maintain supplies during the long, dark winter. The tendency to coat children in sunscreen the minute they step into the sun lowers absorption rates of vitamin D especially amongst children with dark skin pigmentation – the darker the complexion, the more sun is needed to generate healthy levels of vitamin D.

This correlation has been well known for decades. And yet, Scotland appears to have rising numbers of children with rickets – the clearest symptom of severe vitamin D deficiency and usually a product of malnutrition arising from starvation.

In 2010 Professor Faisal Ahmed of Yorkhill Sick Kids Hospital reported 160 children had been admitted with symptoms of vitamin D deficiency between 2002 and 2008. The highest rate of admissions occurred during the last year of the survey. 40 per cent of the children had bowed legs, 19 had suffered seizures, 11 had fractured bones and 13 had limb pain. Almost all the children were of Asian, African or Middle Eastern origin.

But Professor Ahmed notes: “Vitamin D deficiency in cases of European background strengthened our suspicion that (the deficiency) is present across the community. It is highly likely this report is an underestimate of the true incidence of this condition… current public health measures have not yet had a beneficial effect on vitamin D deficiency in Glasgow.”

Dr William B Grant has estimated that if all Canadians took vitamin D supplements (at twice the WHO level) 37,000 lives would have been saved in 2010. In economic terms that would have saved Canadian people and public services an estimated $14.4 billion. How do we know if those figures are reliable? We don’t.

According to Bruce Hollis, professor of paediatrics at the University of South Carolina, “no drug company will fund (a randomised trial) because the vitamin is so cheap to produce”.

So incontrovertible, causal proof of the health problems arising from vitamin D deficiency doesn’t exist – nor (probably) will definitive research ever be commissioned by UK authorities.

Dr Helga Rhein, a GP in Edinburgh’s Sighthill area, has been single-handedly prescribing Vitamin D for her patients – some of Scotland’s poorest, sickest people – since blood tests revealed around 70 per cent were severely deficient. She wants Scotland’s Chief Medical Officer Harry Burns to recommend year-round vitamin D supplementation for all Scots from birth.

He says he cannot. A Scottish Government spokeswoman says: “The Scientific Advisory Committee on Nutrition (SACN) is in the process of reviewing current supplementation recommendations for vitamin D [and] will look at all relevant evidence. The Scottish Government must, therefore, let the review run its proper course before we contemplate any changes. SACN is due to produce a draft report during 2013.”

What’s another year?

I can’t tell you to buy vitamin D supplements – I’m not medically qualified. But I can do what Scotland’s medical authorities apparently cannot and publish some of the evidence. You decide. Podcast with Dr Rhein at lesleyriddoch.com

 

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