British weather isn't known for it's abundant blue skies and sunshine and because of this British people are not getting sufficient amounts of vitamin D. In fact government health advisers have recommended people across the UK should increase their daily intake of vitamin D because gloomy British winters do not provide enough sunshine to maintain healthy levels throughout the year.
An intake of 10mcg (400iu) of vitamin D per day is recommended
A draft report by the Scientific Advisory Committee on Nutrition (SACN) advise that people aged between 11 and 64 should aim for an intake of 10 micrograms of vitamin D every day. This intake is applicable throughout the year, as a precautionary measure, to cover population groups in the UK identified to be at risk of minimal sunshine exposure. This includes those who are housebound or cover their skin for cultural or religious reasons. It would ensure that 97.5% of the population reached healthy levels of vitamin D.
The SACN report is subject to a nine-week consultation period which is due to conclude in September. The final version will be published early next year, after which its recommendations are expected to be adopted as official health guidance.
Supplementation predicted to significantly improve public health in the UK
Dr Adrian Martineau, an expert on vitamin D’s effect on health at Barts and the London School of Medicine and Dentistry, said that a daily intake of 10 micrograms would “significantly improve public health in the UK”.
He predicted that, were everyone in the UK to reach the recommended 10 micrograms, it could lead to the “elimination” of rickets and hypocalcemic seizures – rare manifestations of severe vitamin D deficiency that have nevertheless been on the rise in the UK in recent years. If elderly people were to take more vitamin D, they would be likely to see improvements in muscle strength, which could lead to fewer fractures caused by falls, he added.
Professor Hilary Powers, chair of the SACN Vitamin D working group, said: “It is important to remember that this vitamin D report is draft so the recommendations may change after the consultation period. SACN will be publishing its final recommendations in early 2016 and until then the Government’s current advice on vitamin D remains in place.”Once the consultation is complete, the Department of Health has committed to looking again at the advice on vitamin D. “There is clear evidence that low levels of vitamin D in the body increases the risk of rickets in children and osteomalacia in adults,” a spokesperson said. “Supplements are already available to pregnant women and children under four from low-income families through the Healthy Start scheme."
Why are the British population more likely to be vitamin D deficient?
Natural sunlight is by far the superior source of vitamin D, however as mentioned above we simply do not get enough sunlight in this country to produce adequate levels in the body through the year.
Action of sunlight on the skin is highly variable
Vitamin D is produced by the reaction of ultraviolet-B light with molecules in our skin called dehydrocholesterol - the stronger the sunlight, the paler the skin and the more skin that is exposed, the more vitamin D we can produce. Due to this the action of sunlight on the skin is highly variable and depends on the time of year and the latitude - for example exposure to ultraviolet light is greater in Brighton than in John O'Groats. Whether you like to cover up or wear less in the summer will influence absorption as well as the colour of your skin.
British diet is not conducive to a high intake of vitamin D
Adding to this the average British diet is not conducive to a high intake of vitamin D - in fact current intake levels of vitamin D from foods is less than 5 micrograms per day. This is due to the fact that vitamin D only occurs naturally in a few foods - these include oily fish, red meat, certain mushrooms and, to a lesser extent, from eggs. It is even more difficult for some groups to obtain vitamin D through diet where there is advice to limit oily fish consumption to two servings a week, such as girls and pregnant women.
The draft health report states "Since it is difficult to achieve (safe intake) from natural food sources alone, it is recommended that consideration is given to strategies for the UK population to achieve the recommended nutrient intake."
Indeed, some manufacturers are already fortifying food and drink products with vitamin D. Marks & Spencer recently became the first retailer in the UK to add vitamin D to its entire range of packaged bread products, by using a special type of yeast which naturally boosts vitamin D content. Britain’s main supermarkets are likely to follow suit but until then the use of vitamin D supplements will likely see a sharp rise.
Why is Vitamin D important?
Vitamin D has several important roles in maintenance of good health, we need vitamin D to help us to absorb calcium and phosphorus from our diet – two minerals which are essential for keeping teeth and bones healthy. Having too little vitamin D can damage the way your body absorbs calcium and phosphorus and without adequate vitamin D, bones can become thin, brittle and misshapen. In extreme cases this can lead to rickets in children, a condition involving a softening of the bones that can lead to fractures and deformity. In adults softening of the bones is usually called osteomalacia, causing the person’s bones to become weak and painful, and hampering mobility. Links have also been drawn between vitamin D and the prevention of cancer, multiple sclerosis, asthma, and Type 2 diabetes – though these remain inconclusive.