Staying out of the sun can wreck your health: How one in four Britons is worryingly low in vitamin D
07:10 GMT, 27 March 2012
Are Britons getting enough of the ‘sunshine’ vitamin
Government figures suggest not — a quarter of the population have low levels of vitamin D.
This weekend, a leading arthritis charity urged people to get outside in the sunshine to boost their levels and protect their bones.
And last month, the UK’s four Chief Medical Officers wrote to health professionals to remind them that certain at-risk groups (young children, pregnant and breastfeeding women and those over 65) should take supplements.
Around 90 per cent of our vitamin D is made in the skin with the help of sunlight – this converts the cholesterol found in every cell in the body into vitamin D
They also warned that people with darker skin and little sun exposure are at increased risk of deficiency. But experts believe the rest of us may need supplements, too.
Vitamin D deficiency can cause rickets in children — in adults it can lead to osteomalacia, where the bones become weak and painful.
However, emerging research suggests low levels are linked to a range of other health problems, including a raised risk of osteoporosis, muscle weakness, heart disease, diabetes and even bowel and breast cancer.
Around 90 per cent of our vitamin D is made in the skin with the help of sunlight — this converts the cholesterol found in every cell in the body into vitamin D.
Small amounts are also found in food, with the best sources being meat, offal, oily fish and, to a lesser degree, eggs.
Experts think Britain’s poor sunshine levels mean many of us are likely to be deficient, especially at this time of year.
It may be difficult to imagine when the weather is as glorious as it has been over the past week, but when you factor in our increasingly indoor lifestyles, plus the fear of skin cancer, it seems that many of us are not getting enough vitamin D during the sunny months to sustain us through the year.
The charity Arthritis Research UK used the first day of British Summer Time to warn people of the risks of vitamin D deficiency, specifically in relation to bones — too little can lead to bone loss, poor muscle function and an increased risk of falls and fractures.
‘Vitamin D is also important for general good health, growth, muscle function and a healthy immune system,’ adds Dr William Marshall, a biochemist and clinical director of pathology at The London Clinic.
‘It helps the body to use the calcium and phosphorus obtained from food and regulates cell differentiation, possibly helping to prevent some cancers.’
Ideally our vitamin D levels should be 75 nanomoles per litre of plasma (nmol/L) or above, says Dr Marshall.
‘Anything below 25 is considered clinically deficient, where replacement treatment would certainly be advised — an injection may be necessary to boost levels rapidly.
‘Anything between 25 and 75 is less than ideal and supplements may be appropriate.’
Experts think Britain's poor sunshine levels mean many of us are likely to be deficient, especially at this time of year
The problem is that by the time a deficiency has been diagnosed, rickets or osteomalacia may already have developed, he says.
Vitamin D deficiency is also increasingly being identified among the elderly, adds Dr Trisha Macnair, who is a geriatrician at Milford Hospital in Surrey.
‘We see the effects of this in bone and muscle weakness, and disruption of the immune defences, which are contributing to falls, fractures, infections and many other life-threatening conditions.’
The body can store vitamin D, so the key is to make as much as possible in the summer months — and that means getting into the sun now, say the experts.
‘Generally speaking, the sun is only strong enough for the skin to manufacture vitamin D from the end of March/beginning of April to September,’ says Dr Marshall.
‘You need to get out in the heat of the day, say in your lunch break, exposing your face and arms for around 20 minutes, three times a week, without sun cream. Outside the hours of 11pm to 3pm the sun won’t be strong enough.’
As for fears of skin cancer, he says: ‘There is a big difference between the amount of exposure you need to make vitamin D and that which will cause burning and increase your risk of cancer.’
‘If you’re in the garden with your arms exposed but a hat on, you should be fine for 20-30 minutes without cream. Obviously if you burn quicker than this, then reduce the time. I myself have had skin cancer, but I make sure I get enough sun to manufacture vitamin D.’
However, many people, such as those with darker skin and the elderly, may need up to ten times this exposure, as they find it much harder to make vitamin D, warns Dr Macnair.
‘Also, British summers can be rather cloudy, with little chance for UV light to penetrate.
‘Many people simply don’t manage to get out in the midday sun three times a week, which is why there is official talk about supplements.’
Indeed, both experts themselves take a supplement — Dr Marshall takes 25mcg of vitamin D between January and March, when levels are likely to be lowest; Dr Macnair and her family take the vitamin from November to March.
Although vitamin D levels can be checked with a blood test, deficiency is not something that’s on every GP’s radar, says Dr Marshall. And even less so on the general public’s radar.
But, says Dr Macnair, the more that we learn about vitamin D, the more important it appears to be to our health.
‘You wouldn’t know you were deficient, but inside your body, the implications may be building up — you may not recover from a fall or even a cold as quickly as you could.’
To see how habits and lifestyle can affect vitamin D levels, we asked six people to have their levels tested and analysed by Dr William Marshall — with sometimes surprising results.
Remember, any reading below 75nmol/L shows you lack this vital vitamin…
‘I work nights and sleep during the day’
'I can't imagine I get much vitamin D from my diet – I'm not a fan of oily fish,' said Sarah Weaver
Sarah Weaver, 32, is a TV producer from East London.
Vitamin D levels: 38nmol/L (low)
She says: I don’t get much sun — I work in breakfast television, so I work nights and sleep during the day.
I went sailing in Greece at the end of August for a week, but that was by far the most sun I got all summer.
I can’t imagine I get much vitamin D from my diet — I’m not a fan of oily fish and only occasionally eat eggs.
I do worry about my bones and joints — my mum has osteoarthritis — so I try not to do too much exercise that impacts my joints, such as running.
Other than that, I would say my health is good, but my vitamin D results clearly indicate I’m in need of a sunny holiday.
Expert verdict: Although not in the clinically deficient zone, Sarah is nowhere near the optimal reading — in fact, she’s almost at the level at which we would see the traditional diseases of vitamin D deficiency, such as rickets or osteomalacia.
Over time, this lack of vitamin D could increase her risk of osteoporosis, as she won’t be able to absorb so much calcium from her diet. Night workers are a forgotten at-risk group, as they are likely to be sleeping at the best time to make vitamin D.
If she were my patient, I would recommend a supplement (25mcg a day) from October to March, and in summer she should get a half-hour dose of sun each day at weekends.
Also, rather than avoiding jogging, in moderation this kind of weight-bearing exercise would strengthen her bones.
‘I didn’t realise darker skin increased my risk’
'I didn't realise having darker skin would increase my risk (vitamin D levels),' said Sandra Webb
Sandra Webb, 54, is a charity founder from Great Missenden, Bucks.
Vitamin D levels: 28 nmol/L (very low)
She says: I did wonder if I might be deficient because I don’t go in the sun much, but I didn’t realise it would be so low.
My son Alex, 17, has xeroderma pigmentosum (XP), a genetic skin condition that makes him hypersensitive to ultraviolet light, so he burns easily. All the family has limited exposure to the sun as a result.
Although I knew this would affect my vitamin D levels, I didn’t realise having darker skin would also greatly increase my risk — I am of Afro-Caribbean and Chinese descent.
I’ll definitely see my GP to discuss treatment. I don't want to put my health at risk.
Expert verdict: Sandra has a level we tend to see in someone much older who rarely gets sun exposure.
People with darker skin are a major at-risk group for vitamin D deficiency, as the higher levels of melanin (the substance which gives skin and hair its colour) make it harder for UV light to be absorbed.
Sandra needs vitamin D replacement — it may be she’s given injections to top her up straight away, and then she should begin taking supplements and get some sun exposure.
Otherwise, her risk of osteomalacia and osteoporosis may greatly increase.
‘My wife and I always get some winter sun’
'Working in an office, I don't get much weekday sun during the summer,' said Kevin Kibble
Kevin Kibble, 57, is the chief executive of a charity and lives in North London.
Vitamin D levels: 93nmol/L (ideal)
He says: Working in an office, I don’t get much weekday sun during the summer, although I try to make up for it at weekends.
I don’t bother wearing sun cream when I am in Britain unless I am going to be out in the sun for a long period of time.
I suspect my two-week holiday to India in January has helped my levels — my wife and I go to Goa every year in the winter to do volunteering work — but I do wear factor 15 sun cream there. I also eat oily fish two or three times a week, which I believe contains vitamin D.
Expert verdict: Kevin’s winter holiday has given his vitamin D level a good boost. Although he wore sun cream when he was in India, it could have worn off during the day, boosting his exposure — and besides, you don’t need very much sun to top up your levels.
If he hadn’t had that trip, given that he says he doesn’t otherwise get much sun, he might well have been deficient.
While oily fish has a number of health benefits, you can get only about 10 per cent of the required amount of vitamin D from your diet.
‘Skin cancer worried me, so I’ve never tanned’
'If I do go out in bright sunlight, I wear a high factor sunscreen,' said Abi Smith
Abi Smith, 43, works in online marketing and lives in West London.
Vitamin D results: 56 nmol/L (low)
She says: I have never had a tan in my life, despite growing up in Australia — that’s because skin cancer is a big issue there and as a result I have always avoided going out in the sun.
If I do go out in bright sunlight, I wear a high factor sunscreen.
I work indoors, and get most of my exercise indoors in the winter months (for example, yoga). I started taking vitamin D supplements a year or so ago, but only sporadically.
I was diagnosed with multiple sclerosis in 2007, and my mum suggested it after reading an article which linked taking the vitamin with the condition.
Expert verdict: The fact Abi takes supplements sporadically may explain why her level isn’t lower, given that she rarely goes in the sun.
Because the body can store vitamin D in fatty tissues, even taking it now and again will help, although it’s obviously better to take it every day.
There is no harm with her taking vitamin D for her MS.
There may be a link — the condition is more common at higher latitudes which get less sun, such as in the north of England and Scotland.
‘I’ve taken a supplement for years’
'I never lie out in the sun, as I have enough wrinkles,' said Lee Janogly
Lee Janogly, 72, a fitness instructor from North London, has five children and seven grandchildren.
Vitamin D levels: 120nmol/L (excellent)
She says: I never lie out in the sun, as I have enough wrinkles. I also have a bad reaction to sun cream, which brings me out in red blotches.
As I teach 11 sessions of aerobic exercise a week, I’m aware of protecting my bones, so I have been taking 25mcg of vitamin D every day for the past few years.
In summer, I wait until between 5pm and 6pm when the sun is low and sit out for about 20 minutes to try to get some vitamin D. I also eat salmon, mackerel or herring four times a week.
Expert verdict: Despite the fact she rarely goes out in the sun, Lee has the highest levels of everyone tested, showing that supplementation does work.
Her level is ideal — most people of her age would have a much lower reading, partly because many older people don’t get enough sun and partly because it’s harder to manufacture vitamin D with age.
Vitamin D deficiency is associated with muscle weakness so if you’re elderly, this increases the risk of falls, disability and often fatal hip fractures.
There’s no need for Lee to go in the sun if she doesn’t want to — supplements provide the same benefit as sunshine. It’s worth noting that going out in the late afternoon won’t do much, if anything.
You need to be out when the sun is strongest — between 11am and 3pm — to synthesise any vitamin D.
You’ll get much more from your supplement if you take it with a main meal — vitamin D is a fat-soluble vitamin.
‘My friends and I don’t go in the sun’
'Like most of my friends, I don't get out in the sun much,' said Conrad Hench
Conrad Hench, 18, is unemployed and lives in Kingston, Surrey.
Vitamin D levels: 47nmol/L (low)
He says: Like most of my friends, I don’t get out in the sun much — I prefer being in the shade.
When I am in direct sunlight, I usually wear three-quarter-length shorts and a T-shirt.
My mum worries that I’m low in vitamin D — my nine-year-old brother, Harvey, is deficient, which has caused him problems with tooth decay.
I was calcium deficient when I was younger, so my bones may not be that strong anyway; my joints are already quite painful. If I was told to take a supplement, I would do so — I don’t want to store up problems for the future.
Expert verdict: Conrad’s result has nothing to do with his age — he’s typical of many people in this country who don’t spend enough time in the sun. He needs to try to get some sunshine.
What is slightly more concerning is that vitamin D helps the absorption of calcium from the diet, so Conrad’s low levels won’t help.
Given this, I’d suggest the family seek medical advice.
Testing was carried out at the London Clinic’s pathology laboratory — for pathology tests patients must be referred by their GP or consultant.