Focus: Here comes the sun... so should we run for cover?

Yes, say experts, stay in the shade! No, say experts, get out there! What's a red-headed, fair-skinned girl to do? As a child Katy Guest's mother put her on sunbeds to toughen her up. Today she reaches for the Factor 15 and considers the latest evidence

Go on, get out there. Get your kit off, lay down in the sun for as long as possible, in the hottest part of the day. Don't bother with suncream, just let those friendly, cosy ultraviolet rays work their warming magic. It's okay, the experts say soaking up the rays is good for boosting levels of vitamin D needed for healthy bones, muscles and immune systems. The advice is clear. Oh, hang on though, they also say you musn't get burnt. And what about all those campaigns telling us the sun should be avoided at all costs, because skin cancer rates are rising fast and there's no such thing as a safe tan?

Go on, get out there. Get your kit off, lay down in the sun for as long as possible, in the hottest part of the day. Don't bother with suncream, just let those friendly, cosy ultraviolet rays work their warming magic. It's okay, the experts say soaking up the rays is good for boosting levels of vitamin D needed for healthy bones, muscles and immune systems. The advice is clear. Oh, hang on though, they also say you musn't get burnt. And what about all those campaigns telling us the sun should be avoided at all costs, because skin cancer rates are rising fast and there's no such thing as a safe tan?

Actually, the advice is as clear as a pair of shades smothered in sunblock.

Sunburn is basically radiation sickness: ultraviolet rays damaging the skin and its DNA. We do like to rush out and flash fry ourselves at the first sign of warm, which is why Cancer Research UK is cranking up its annual SunSmart campaign now. Every year 1,600 people in Britain die because of malignant melanoma, the deadliest form of skin cancer. That is 600 more than Australia, one of the sunniest countries in the world.

Rates have trebled in the last 30 years, and if we don't start behaving more sensibly they will treble again in the next 30. The advice is stay out of the sun between 11am and 3pm, but if you must go out then wear a hat, slap on cream with a factor of at least 15, half an hour before you leave the house. And above all keep your children out of the sun, because we get 80 per cent of our exposure of it before we are 21 and that is when the damage that causes skin cancer later in life is most likely to be done.

All of which advice seemed perfectly straightforward until last week, when even the campaigners started to admit they might have gone over the top. Other scientists say staying in the shade can lead to a serious deficiency of Vitamin D, a condition which has been linked with heart disease, schizophrenia, diabetes, multiple sclerosis and cancers of trhe colon, breast, ovary and prostate. Our stores of D run low in the winter and start to build up again when the sun comes out.

Last year the Health Research Forum advised that a white-skinned person in Britain needed at least three 20-minute sessions of bathing in bright noonday sun every week to enable their body to produce the maximum Vitamin D. Oliver Gillie, of the Forum, said campaigns based on the belief that no sun tan is safe make "no concessions to the health benefits of sunlight" and "continuing with government recommendations can only increase vitamin D deficiency in the population and so lead to an increase in ill-health and premature death".

Even the Cancer Council of Australia, which is now seeing dramatically decreased rates after a campaign lasting two decades, admitted "a balance is required between avoiding an increase in the risk of skin cancer and achieving enough ultraviolet radiation exposure to ensure adequate vitamin D levels".

In the old days, of course, a tan meant you worked in the fields. Eighteenth century ladies powdered their faces to look white - and poisoned themselves with the lead in the chalk. Coco Chanel is supposed to have invented the tan. What she actually did was over expose herself while riding the Duke of Wellington's yacht in 1923. The inventor of the little black dress was always so closely watched that she turned up in the south of France with a teak face the fashion world it as an order. Vogue advertised its first sun lamp the same year. Coco's enthusiams coincided with new medical theories about fresh air, loose limbs and the benefits of sunshine, which led to the building of glorious lidos all over Britain. Here anybody, rich or poor, could bask beside a glittering expanse of water. Or freeze to death in the British summer, not yet tropicalised by global warming.

My generation, now around 30 years old, is the first to grow up with regular trips to the sun, thanks to the package holiday boom of the Seventies. We also went backpacking - and no matter how wasted you were on that beach in Goa, a tan made you look healthy, we thought. We are reaping the whirlwind.

Sunbeds are sometimes thought to be the safer option. They only account for eight per cent of melanoma cases, but do cause 100 deaths a year. Cancer Research UK would like to see all children aged under 16 banned from using them.

I was 11 when I first got into one, an enormous, humming, ultraviolet alien of a machine. We were going on holiday to Majorca, and my mum wanted to toughen up my skin in advance. I had suffered hallucinatory sunstroke on our first holiday abroad: mum had to talk me down as I ranted about the little men trying to make me straighten out all the air.

I have always been fair-skinned, whereas my parents tan easily - apart from their honeymoon, when a comedy Greek advised Dad to smear himself in olive oil. He fried like a falafel. I vividly remember standing on the beach grimacing as I was scoured with sand in a handful of greasy sun cream. I remember crying all the way home from the beach, wincing as each step pulled at the burnt skin on the backs of my legs.

I am a lot more careful now, but do worship the sun. I wear Factor 15 always, and top up that faint natural glow by practically bathing in fake tan, but it's not the colour I want - it's the uniquely decadent feeling of lying in the garden, just drinking in the sun along with the scent of sweet peas. I love the way skin smells when it is beginning to turn pink: like pepper and musk and the fat on the top of proper gravy. It feels like I am soaking up warmth through my pores, and then walking around for the rest of the evening with sunlight still seeping out of me.

I understand the dangers of what I'm doing. But I deeply resent it when someone comes and casts a shadow over me and tells me off for damaging my skin. I'm infuriatingly healthy in most other ways, I check my moles religiously and I suspect that in my case the damage has already been done. Anyway, why is it always smokers and exercise-phobics who have a go at me about the danger to my health? Are they topping up their vitamin D with their fags and burgers? I really don't think so.