Everyone enjoys a bit of sunshine – we grab it while we can in this country – but in recent years there has been a backlash against lying in the sun, due to the real risk of skin cancers – which are on the rise in the UK.
However, sunshine on the skin does more than give us a healthy glow and a boost – it is vital for the synthesis of Vitamin D – probably the hottest vitamin around right now in terms of new research about its importance for health. Research has shown that Vitamin D has far more relevance than just helping to build strong bones. D’s role in bone strength has been known for a long time, ever since a Polish doctor in the early 19th century cured city children of rickets by sending them to the countryside to get more sunshine.
As well as recognising the many important roles Vitamin D has to play in health, scientists have also recognised that many people are not getting enough. One result of this is that it is now government policy that certain groups of people should take a 10 microgram supplement of Vitamin D every day, to avoid deficiency. Those deemed at risk of deficiency include: people with dark skin, people who work indoors and don’t go outside very much, the elderly, pregnant and breast-feeding women, people following a vegetarian or low-fat diet, and people who cover up most of their skin when they go outside for cultural reasons.
In terms of children, current Department of Health advice is that all infants and children under 5 years of age should take supplements containing at least 7 micrograms (280 IU) of vitamin D daily.
There are also plans to set a minimum daily reference intake (known as an RNI) for Vitamin D for adults too, as currently in the UK there is only an RNI set for children, adults over 65 and those deemed at risk of deficiency. The RNI is 10 micrograms (400 IUs).
If you are thinking of taking a Vitamin D supplement it is a good idea to visit your GP and ask for a blood test to check Vitamin D status first. This test is also available through Key Nutrition.
Vitamin D and immunity
Clear associations have now been made between low Vitamin D levels and certain cancers; auto-immune diseases such as type 1 diabetes, rheumatoid arthritis and muscular sclerosis; and infectious diseases such as flu. The reason for these associations is the fact that the active form of Vitamin D in the body – 1,25 dihydroxyvitamin D – travels to many different organs and cell types where it alters cellular function by triggering gene activity.
At least 1,000 different genes are believed to be regulated by this active form of Vitamin D in the body. Many of these genes have critical roles in cellular defense – which is why this sunshine vitamin has such an important role to play in immunity, including cancer protection.
Where to get Vitamin D
The good news is that there is more than one way of increasing your intake of this sunshine vitamin. Some foods contain Vitamin D and these are generally healthy foods such as oily fish, shiitake mushrooms, eggs and fortified dairy products. However, the amount of active Vitamin D found in these foods is minimal compared to the amount made by exposure to sunlight.
We all want to know how much sun exposure we need in order to maintain good Vitamin D levels, while not exposing ourselves to the risk of developing skin cancers.
There is some difference of opinion on this matter amongst different parts of the scientific community. Dermatologists have always believed that any sun exposure without protection is both bad for the skin and raises the risk of skin cancers. Hence the many high profile campaigns telling us to wear suncream at all times, and to never let our children outside without it covering every inch of exposed skin.
Those on the other side of the fence are the scientists and researchers looking into Vitamin D, who generally believe that without some unprotected sun exposure during the summer months we are very likely to be deficient in this important vitamin. Many of them also believe that the RNI for Vitamin D should be much higher than it is now given all the research demonstrating its role in so many common diseases of the 21st century.
Sensible advice for sun exposure is 15-20 minutes two to three times a week during the summer months, longer if you have darker skin, less if you are very pale. After that length of time put on sunscreen. SPF 15 reduces production of Vitamin D by 99%, because it blocks the UV rays. Most importantly do not allow your skin to burn.
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