On the first morning of the hopeful new world after Obama's victory, I went for a walk in the wet autumnal woods, breathed in the colours, and gave thanks.
Then, I went home and reached for the cod liver oil. A strange way, you may think, to celebrate. No; I had just read Oliver Gillie's book about the role of vitamin D and cod liver oil in keeping us healthy and had resolved to adopt evidence-based personal practice. A daily dose of cod liver oil was something that my grandfather, having survived the trenches, passed on to my father and the smelly ritual was a strong childhood memory which I had decided never to emulate.
I have regularly advised patients to consume oily fish and to consider omega 3 oils but, like much of our advice, I had chosen to largely ignore it myself. This book changed that. Oliver Gillie, previously the medical correspondent for The Sunday Times and medical editor of The Independent, originally a geneticist and for many years a passionate good food campaigner, has pulled together the evidence for insufficient vitamin D being an important factor increasing the risk of several chronic diseases including cancer, heart disease, multiple sclerosis, hypertension, stroke, diabetes, and arthritis, as well as bone disease and fractures.
Since healthy people get more than 90% of their vitamin D from exposure to the sun and since Scotland receives less sunlight and has a shorter summer season than England, Scots have lower levels of vitamin D than English people. These levels, along with poverty, diet, alcohol and smoking, contribute to the higher incidence of chronic diseases and higher premature mortality in Scotland and Gillie is determined to get the Scottish government and public health establishment to do something about it; hence the book's title, Scotland's Health Deficit: An Explanation And A Plan.
A previous publication, Sunlight Robbery,1 published in 2004, earned Gillie praise from Sir Richard Doll. In this, he challenged the accepted wisdom that sunshine, in the name of skin protection, is to be shunned, and showed that the mistaken advice from the British government and Cancer Research UK2 to avoid exposure to the sun between 11am and 3pm can only have pushed down levels of vitamin D. Advice urgently needs to be adapted to warn against burning rather than sun exposure.
In this latest extensively referenced book, Gillie examines the ‘silent epidemic of autoimmune diseases’, multiple sclerosis, type 1 diabetes, Crohn's disease, and rheumatoid arthritis. MS especially deserves attention; Scotland has the highest incidence in the world and Gillie presents the evidence for its link with latitude, lack of UV exposure, and vitamin D ingestion and describes ongoing trials of treatment with vitamin D to reduce relapses. Dental and bone health are both improved by vitamin D and both the Canadian and US governments recommend supplements for healthy adults while the Australian government is now questioning its ‘slip, slap, slop’ advice which provided Cancer Research UK with its model for its SunSmart programme.2
After publishing Sunlight Robbery, Gillie set up the Health Research Forum with the aim of developing an up-to-date public health policy about vitamin D based on scientific evidence. In 2005, the Forum held a conference at the House of Commons and since then has lobbied policymakers to respond to the evidence. Trials are still underway to establish the optimum dose for prescribed vitamin D and doctors in the UK still lack a suitable range of prescribable vitamin D at high enough doses.
But, in the meantime, encouraging patients to improve their health by being outside enjoying the outdoors, safely soaking up the sun, appeals as fairly positive, life-affirming activity.
Let's drink (though not necessarily cod liver oil) to sunshine, health and hope.
- © British Journal of General Practice, 2008.