Following an exceptionally bad summer, vitamin D levels of people in the UK are low and will become lower still over the winter increasing the risk of common illnesses. World Vitamin D Day is being established on November 2nd by organizations across the world to highlight the problem and promote the importance of vitamin D for health.
November is the beginning of our “Vitamin D Winter” in the Northern Hemisphere. The c locks have moved back and a four-to-five-month period begins when people’s vitamin D levels plummet because winter sunlight contains little UVB – the rays that produce vitamin D in skin. Humans make and store abundant vitamin D during exposure to summer sun but avoidance of the sun because of fear of skin cancer and overuse of sunblock causes vitamin D deficiency which gets worse during winter. The “Vitamin D Winter” affects all of Europe,Canada, and much of theUnited Statesdown to mid-California in the west andAtlantain the East.
The winter season of colds and flu results from reduced resistance to infections caused by low blood levels of vitamin D during the dark months, scientists interested in vitamin D believe. Randomised clinical trials, the highest level of proof in medicine, have shown that vitamin D improves resistance to infections such as flu and tuberculosis. Insufficient vitamin D is also linked to a wide spectrum of diseases that include diabetes, arthritis, multiple sclerosis, a number of other autoimmune diseases, and probably also to several types of cancer, particularly cancer of the bowel.
The Chief Medical Officers forEngland,ScotlandandWalesrecommend that vulnerable groups, such as the house-bound elderly, darker-skinned ethnic minorities, young children and women who are pregnant or breast-feeding, should take regular vitamin D supplements. However, Dr Richard Quinton, a Newcastle endocrinologist, says: “After such a bad summer, vitamin D levels are likely to be even lower than usual in the UK population and this could potentially be associated with an increased risk of winter colds, flu and chest infections, so many more people in the UK might benefit from taking a vitamin D supplement especially in winter.”
Nick Clarke, professor of orthopaedics atSouthamptonUniversity, says he is outraged by the amount of bone disease he sees in chi9ldren which is totally avoidable: “Teenage girls wear so much make up, which nowadays contains sunblock, together with long sleeves and tights that they get very little summer sun. As a result they develop musculo-skeletal pains and bone deformities. It is an outrage that this is being ignored. Disease caused by sun avoidance far exceeds any harm that might come from moderate sun exposure.”
East African tribes living an entirely natural lifestyle have high average levels of vitamin D (measured to standard units as 115 nanomoles/litre), according to a 2012 study published in the British Journal of Nutrition1. These tribes get their vitamin D from year-round daily sun exposure. Dr. Reinhold Vieth, professor in Nutritional Sciences at theUniversity ofToronto and international expert on vitamin D, points out this study is important because it establishes what the natural biological level of vitamin D would have been when human beings first evolved in the African Great Lakes region many thousands of years ago. White skin, which makes vitamin D quicker than black skin, evolved much more recently, some 18,000 years ago, when human beings moved to northern climates which provide little or no vitamin D in winter.
Dr Vieth says: “Vitamin D is the raw material that cells in the body require to communicate properly with each other. If you expect sunshine to provide you with vitamin D, then you’d better make sure that the sun is high enough in the sky, because when the sun is low on the horizon it cannot help skin make vitamin D.”
Worldwide vitamin D experts recommend vitamin D blood levels be maintained between 100-150 nanomoles/litre, a level which is achieved by very few people in the British Isles2.Britain andIreland, as well as being far north, have a very cloudy atmosphere and so we have one of the least sunny climates in the industrial world. Most people in theUK, except possibly for those who go for a winter sun holiday, will benefit from taking a vitamin D supplement in winter.
Dr Helga Rhein, an Edinburgh GP, is a vitamin D pioneer. She says: “In Scotland we get very few days when it’s warm enough to be out of doors with short sleeves and I find that many of my patients are deficient in vitamin D. I regularly recommend patients to take a vitamin D supplement and also prescribe it for many.”
Vitamin D expert Dr. Robert Heaney, Professor of Medicine atCreightonUniversityand Research Director of campaigning organisation GrassrootsHealth, recommends an oral intake of “75 IU of Vitamin D3 supplement per kg of weight, per day.” For many adults this means about 4,000 IUs per day, a dose which is recognised by EFSA, the European Food Safety Authority, as a safe level. Dark skin makes vitamin D more slowly than white skin. So people with dark skin living in theUKare likely to be vitamin D deficient and will specially benefit from taking a vitamin D supplement.
Background
The Vitamin D Society created November as Vitamin D Awareness month in 2007, to help draw attention to vitamin D deficiency in Canada. “We are excited to grow this focus worldwide with other partner organizations by recognizing Vitamin D Day on November 2nd ” said executive director,Perry Holman.
InspireHealth established Vitamin D Day November 2nd inCanadain 2009. From its humble beginnings inVancouverit has grown, supported by proclamations in communities acrossCanada, to an international event. This grassroots public health movement inspired Dr. James Lunney, Member of Parliament for Nanaimo-Alberni to introduce Bill C-388, An Act to establish National Vitamin D Day. Dr. Lunney reported “saving money on Canada’s healthcare budget doesn’t necessarily mean cutting back on anything, merely increasing people’s dosage of vitamin D can keep people healthier, requiring fewer visits to either the doctor or the hospital.”
Joining InspireHealth and Dr. James Lunney in the promotion of Vitamin D Day – November 2nd are GrassrootsHealth, a public health research and advocacy group from San Diego CA, the Vitamin D Council, USA, Oliver Gillie, Health Research Forum, UK and the Vitamin D Society, Canada.
For more information visit: www.vitamindday.ca, www.GrassRootsHealth.net and www.healthresearchforum.org.uk.
For further information, please contact:
Oliver Gillie, director, Health Research Forum, Phone: ++44 20 7561 9677
Mobile: 07774 995 805 [email protected]
Perry Holman, Vitamin D Society, Canada, 001 877-520-4867
[email protected]
References
- Luxwolda MF, Kuipers RS, Kema IP, Kema IP, Janneke Dijck- Brouwer DA, Muskiet FA (2012) Traditionally living populations inEast Africahave a mean serum 25-hydroxyvitamin D concentration of 115 nmol/l. Br J Nutr 23:1–5
- Hypponen, E., Power, C., Hypovitaminosis D in British adults at age 45 y: nationwide cohort study of dietary and lifestyle predictors. Am. J. Clin. Nutr. 2007, 85, 860–868.