Yahoo Lifestyle Vitamin D Deficiency: Are You At Risk?
As she slathered on sunscreen every morning before leaving home, Robyn Hynes felt totally confident she was protecting her fair skin and future health. “I burn easily, so from childhood I’ve stuck to those messages we’ve all had drummed into us about staying out of the sun and wearing sunscreen to prevent exposure to damaging UV light,” says the 30-year-old graphic artist from Sydney. Hynes had seen the sobering, scary ads about sunbaking causing melanoma and didn’t want to become another cancer statistic. “Their message is very clear – the sun is bad for you – so the less exposure the better. I lived by that and had absolutely no idea that not getting enough sun could be putting my health at risk.”
Her wake-up call came in 2012 when Hynes was eight weeks pregnant and a routine blood test showed that although she felt fine, her vitamin D level was severely low. “My doctor was so concerned she told me to start taking vitamin D supplements that day,” recalls Hynes. “When she explained that my deficiency could be damaging my bones and the skeleton of my unborn child, I felt sick with concern that it may have harmed my baby. It’s been a continuous worry throughout my pregnancy.”
Like millions of Australians, Hynes had slavishly followed the directions of the public health campaigns, which told her that staying out of the sun was best. “So I was shocked to Google the topic and read about all this evidence that lack of sunshine and vitamin D may have been increasing my risk of many serious diseases like cancer,” she says. “Why isn’t our government doing more to get that message out? If I hadn’t started a family I’d never have known my lack of sun was damaging my health.”
Vitamin D is a fat-soluble vitamin crucial to preventing soft bones (called rickets in children and osteomalacia in adults). While foods like oily fish, eggs, margarine and milk provide a dollop of your daily vitamin D, 90 per cent of it is made in your skin. When the sun’s UV rays strike your skin they react with a compound called 7-dehydrocholesterol, a “cousin” of healthy cholesterol, which becomes activated and helps your body produce vitamin D. As well as entering your bloodstream, vitamin D enters your gut, where it absorbs the bone-building minerals calcium and phosphate.
Vitamin D deficiency is on the rise in Australia, and statistics show that low vitamin D levels are no longer simply a risk for people who have dark skin, cover up for cultural reasons or are bed-bound, such as the elderly in care.
A University of Sydney study of about 24,000 people revealed that 58 per cent are vitamin D deficient. Unsurprisingly, people living in the city are often lower in vitamin D, most likely because of the daily indoor shuffle from home to office, then to a cafe or shopping mall for lunch, with minimal exposure to the sun.
“Our research shows that women in general are at higher risk, including young women in their 20s and 30s,” says Professor Steven Boyages, an endocrinologist at Sydney’s Westmead Hospital and clinical professor at The University of Sydney’s Medical School. “We think this is because they have taken those sun-protection messages onboard.”
In a sunburnt country like Australia, it seems bizarre that so many of us have an ailment related to sun deficiency. Although traditional sun worshippers, Australians started to pack away the baby oil once they became “SunSmart” in 1981, courtesy of a campaign starring Sid the Seagull who ordered us to “slip on a shirt, slop on sunscreen and slap on a hat”, and not to “sizzle like a sausage” because “skin cancer isn’t so hot”.
In subsequent decades, sunshine has undergone some deservedly bad press. It’s been blamed for melanomas and other skin cancers, and cataracts that compromise eyesight, as well as the photo-damage that leads to skin ageing. Its role in these conditions is undeniable and needs to be taken seriously. But has the message swung so far in the opposite direction that shunning the sun is leading us into a vitamin D deficiency danger zone? Apart from causing osteoporosis, a lack of vitamin D has been linked to life-threatening diseases, such as cancer, heart disease and diabetes. “We now know from studies that vitamin D deficiency is linked to cancer of the prostate, breast and, in particular, to bowel cancer – though it’s not yet clear why,” says Professor Ian Olver, CEO of Cancer Council Australia.
Meanwhile, new research continues to unveil a rollcall of benefits for the underrated vitamin. Studies reveal that adequate or higher levels of vitamin D help the immune system fight illness and viruses like the common cold more effectively, improve lung function in people with asthma and help protect against stroke and depression.
“Mounting evidence shows that vitamin D has protective effects against many health conditions, including cardiovascular disease and autoimmune diseases such as rheumatoid arthritis, multiple sclerosis and type 1 diabetes,” says Professor Bruce Armstrong, chair of the NSW Skin Cancer Prevention Advisory Committee and professor of public health at University of Sydney.
The National Health and Medical Research Council is tracking studies on whether boosting vitamin D levels can decrease dementia in the elderly, cut diabetes risk in susceptible children and lower schizophrenia risk, now thought to be linked to inadequate levels of vitamin D in pregnant women. (A 2011 study at Westmead Hospital found that 40 per cent of a group of pregnant women with gestational diabetes were found to be vitamin D deficient.)
One of the issues with vitamin D deficiency is there are no obvious signs to look out for. This was the case for Sydney psychologist Danielle Byers, 36. When her once silky hair became brittle and started falling out in clumps in July 2010, she initially blamed stress from working long hours. “But after a year I suspected something else was not right because I was chronically exhausted,” she recalls. “Getting through the day felt like a marathon, even though I was eating a good diet and exercising. I was also taking much longer to recover from colds and scratches on my skin – so my immunity was clearly low.”
Byers had a blood test, which showed she was severely vitamin D deficient. Her problem? Skimping on sun. For years she’d been leaving for work and getting home in the dark, wearing sunblock every day and rarely getting out at lunchtime. “I’d thought avoiding the sun was good practice,” she says. “I had no idea that not getting enough UV could make me unwell. Now that supplements have increased my vitamin D levels, I feel back to my old energetic, happy self. I’m now on a mission to tell every woman I know how important it is that they enjoy a little daily sun exposure.”
So are supplements the answer? Though a quick way to boost levels, they should be used with caution. “Vitamin D from supplements appears to be as effective as vitamin D from the sun,” says Professor Armstrong.
“However, your body switches on an internal control to ensure you don’t get too much vitamin D from the sun and with supplements this control doesn’t work. This does create a risk, though low, of getting too much vitamin D through overuse of supplements. In excess, vitamin D can cause complications ranging from vomiting to serious issues like kidney problems and high blood pressure.”
It also lasts half the time in the body as does vitamin D from the sun, according to Dr Michael Holick, author of The Vitamin D Solution (Scribe, $35).
Clearly, the sun needs a new PR spin to spread the word about its benefits. That doesn’t mean you should don your bikini and head surfside all weekend. Sun exposure is still regarded as the biggest cause of skin cancer, which will affect two in three Australians by age 70.‡ “We need to be extremely careful that years of sun-protection campaigns are not undermined by confusion about sun exposure and vitamin D,” says Dr Pip Youl, head of programs and research
at the Cancer Council Queensland.
“We did a survey which showed that nearly one third of Australians already mistakenly believe a fair-skinned adult requires at least 30 minutes of unprotected sun exposure each day in summer to maintain vitamin D levels.”
What no expert denies is that a short sunbath should be as much a part of your daily routine as brushing your teeth. “We’ve done a great job educating people about reducing sun damage; now we need to ensure people know the importance of a little sun for optimal health,” says Professor Olver. The take-home point is simple – aim for between six and 10 minutes of daily sun in summer and 20 minutes in winter. To produce enough vitamin D, this sunlight should be directly felt on face, arms and hands or the equivalent area of skin, without sunblock (see box on opposite page).
“However, sun exposure should come outside peak UV times in the morning, before 11am, or the afternoon, after 2pm, when the sun is not at its hottest,” warns Professor Olver.
According to Professor Rebecca Mason, deputy director of the Bosch Institute at the University of Sydney: “Short sun exposures, preferably on as much area of skin as possible, are much more efficient [than longer ones] for making vitamin D.” Here’s why: your skin can repair small amounts of sun damage far more effectively than it can repair damage from longer periods spent tanning“If you have fair skin, once your exposure goes longer than 10 minutes or so on a hot day, your body starts to break down the vitamin D you have produced in order to protect your skin,” explains Professor Mason. “Stay too long and you risk depleting the very vitamin D that the sun just helped your body make.”
Paradoxically, studies have linked low levels of vitamin D to melanoma. However, this is not an open and shut case. “Although vitamin D may help the body better combat cancer when people develop it, there is no doubt that the sun contributes to the development of skin cancers – so again the message needs to be about short, balanced exposure being of benefit, and sunburn and suntans being avoided,” states Mason.
What’s amply clear is we’ll be hearing much more about vitamin D in the future. “Exactly how it does all the important work in our body that protects against disease is still in part a medical mystery,” says Professor Arm-strong. “We are trying to unravel it.”
Vitamin D's allergy links
Cutting-edge research is now showing a link between vitamin D deficiency and the development of allergies in children. Low levels of the important sunshine hormone appear to be linked to:
In a 2011 study of 3000 children by the Albert Einstein College of Medicine in the US, children with lower vitamin D levels were sensitive to 11 out of 17 allergens tested, such as dogs and pollen.
“At the Murdoch Childrens Research Institute (MCRI) our research has shown that children with vitamin D deficiency are six times more likely to develop peanut allergy compared to children who have adequate vitamin D,” warns Jennifer Koplin, a research fellow at MCRI. “Other food allergies were higher, too.”
Asthmatic children with lower levels of vitamin D have poorer lung function, according to recent research from the US.
“In the Australian states where levels of sunshine all year round are higher, such as Queensland and New South Wales, there is a lower rate of allergies, including eczema in children,” says Koplin. “In states such as Victoria and Tasmania where sun exposure is lower, the incidence of allergy is higher and this appears to be linked to lower levels of vitamin D.”
