Vitamin D easily obtained with little or no sun exposure

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Published: 11 Sep 2014
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Prof John Hawk - President of the World Congress on Cancers of the Skin 2014

Prof Hawk talks to ecancertv at the Word Congress for Cancers of the Skin 2014 (WCCS) in Edinburgh, Scotland, about his work which looks at counteracting claims that the need for vitamin D makes sun exposure, including sunbathing, part of a healthy lifestyle.

There has been a lot of concern about vitamin D and how much exposure you should have to the sun to get it because most people get their vitamin D from sunlight. But you also get sunburnt and you get aging and cancer from too much sun exposure so there has been a major discussion over the last few years as to what we should be doing to get enough vitamin D. There have been proponents of lots of sun exposure and don’t worry about getting damage which leads towards skin cancer and there are other people who say that you shouldn’t do that.

There’s very good evidence now that just low doses of ultraviolet from normal walking around outside for short periods regularly, even if you’ve got sunscreen on, that this produces bacterial defences which stop us getting infected because the immune system is also suppressed at the same time in the skin only which enables us to not get allergic to all sorts of substances in the environment. It also has been shown to produce nitric oxide which dilates the blood vessels and reduces blood pressure. Finally, it’s enough to produce vitamin D so we do not need to give people advice to go out in the sun specifically to get enough and we certainly don’t advise them to sunbathe for that reason and we certainly don’t advise them to use sunbeds, which lots of sunbed companies do suggest. So just normal life is enough to get enough vitamin D and even if you use a sunscreen.

Is it important to wear sun cream even in countries which are colder, such as Scotland?

Even if you’re in Scotland, and that brings me to another point which has shown that the average vitamin D in summer and in winter, which is lower, is the same in Hawaii and Lapland and all the places in between because there’s a negative feedback system which means that if you don’t have enough a little amount of ultraviolet will push the level up of vitamin D and if you have too much it doesn’t make much difference. So it doesn’t matter where you live, there’s a system which works. But if you do happen to be confined inside all the time because you’re ill or maybe you work during the day inside and only go home in the dark and go to work in the dark, well you can get low vitamin D then and if that’s the case you shouldn’t be advised to go and sunbathe or use a sunbed, you should be advised to take oral supplementation which is safe and just as effective.

Does there need to be more regulating of sunbeds?

Yes, sunbeds have been around for a long while and they’re getting worse and worse in terms of their output. A lot of them have outputs which are far higher than the sun which the human body hasn’t evolved to take care of and we don’t even know how severe the damage is. We do know that it moves towards producing cancers of the melanoma form and also the long melanoma form, all of which provides a burden on the NHS as well as on the person who gets them. So sunbeds should be restricted for young people and Wales and Scotland have done that and England have recommended it and I think that’s essential. It’s difficult to see whether total bans are going to be a good thing. They have been totally banned in Brazil; it’s considered perhaps… I’m not sure if this is confidential but it probably doesn’t matter, it’s been considered that nobody would want to be using sunbeds in Brazil anyway so it may be a money laundering method. So they’ve been banned there but they’ve been banned in Australia as from the end of December this year. I think that they should be completely banned for under-18s and that older people should be warned that they’re not good for you but they’re allowed to make their own decisions.

Could you tell us a little about sun damage and pre-cancers?

As we go through life we expose our skin and we may use sun creams but most people don’t use them very well. Particularly some years ago when a lot of the older people were not using sun creams and we developed accumulating damage to the skin which means that we start getting pre-cancers if we’re fair skinned and dark skinned people don’t really get this but you get patches of pre-cancers and some of those pre-cancers go on to become full cancers. People have tended in the past to treat these pre-cancers but it’s been shown that the whole of the area that’s exposed, because your whole forehead, for example, would be exposed, it’s been shown that all the skin in between is also almost as damaged and it’s just random bad luck as to which patch gets what. So it’s recommended that one takes care and uses a variety of treatments that are available now to treat, perhaps, the whole area rather than just the areas as they pop up. Although the areas that just pop up can also be treated with quite good success rates but the whole of the skin is affected and it’s just some little bits that happen to have enough damage to go over the top, as it were.