Sun supplement
Do we all need to be on the 5:2 sunshine diet?
When Paul Banwell, a consultant plastic surgeon and skin cancer specialist, was doing his fellowship in Australia more than 10 years ago, he discovered a peculiar fact: virtually all the dermatologists he was working alongside in Sydney and Brisbane were vitamin D deficient. One even had a pathological fracture (a bone fracture caused by weak bones).
“They cover up in the sun the whole time over there, both with clothes and sun cream,” explains Banwell. “As a skin cancer expert myself, I tell patients to wear sunscreen every day, but in Australia they take the sun safety message to the extreme, and they’re lacking in vitamin D as a result.”
This anecdote may go some way to explaining the increasing levels of vitamin D deficiency worldwide. The sun safety message – which started with Australia’s 1981 Slip! Slop! Slap! public health campaign to reverse the country’s soaring rates of skin cancer – was so well absorbed by countries like the UK and US, that people’s concern about protecting themselves from the sun meant they overlooked its health benefits. Namely, how it helps the body produce vitamin D.
Yet this week, a slew of studies presented at the American Society of Clinical
Oncology annual
conference in Chicago found that vitamin D – from both sunshine and supplements – could reduce your risk of dying from several types of cancer. The experts at the conference couldn’t say why, but suggested vitamin D may enhance the body’s immune response, and Dr Tarek Haykal, a lead researcher from Michigan State University, urged GPS to recommend supplements.
“We now know that good levels of vitamin D are linked with a reduced risk of a variety of different cancers,” says Banwell. “At last count it was 15 types, with the main ones being colon, prostate, breast and skin. It’s a bizarre paradox that vitamin D from the sun actually helps to protect against skin cancer. It seems to be protective on a cellular level.”
The conference referenced studies that found those told to take vitamin D supplements were no less likely to get cancer, but were 13 per cent less likely to die from the disease. Supplements were linked to a 38 per cent drop in prostate cancer deaths, while the link with pancreatic cancer was also strong – being deficient in vitamin D can double your risk of developing it.
“Vitamin D is a fat-soluble vitamin stored in the body,” explains dietitian Helen Bond. “The sun is by far the best source, but you can also get it from food and supplements. For years, we’ve known vitamin D maintains healthy bones. But in recent years, there has been a lot of new and exciting research suggesting it can help protect against certain cancers, diabetes, age-related macular degeneration, cardiovascular disease, mental decline, multiple sclerosis and rheumatoid arthritis.”
Another study has found it can increase fertility in both men and women, improve the chances of IVF success, and help regulate menstrual cycles in women suffering from polycystic ovary syndrome. Yet it’s thought one in four British adults is vitamin D deficient.
Not that it’s just overzealous sun safety driving this: the dreary British weather, and our increasingly busy, office-based, Netflix-addicted lives are also playing a part. “People spend significant amounts of time at work in a concrete building and have much less time for leisure, let alone being exposed to nature and sunlight, so vitamin D deficiency is prevalent,” said Dr Shifeng Mao, from Allegheny Health Network Cancer Institute, at the Chicago conference.
So just how much do we need? The NHS recommends babies up to the age of one need 8.5 to 10 micrograms of vitamin D. Children from the age of one need 10mcg of vitamin D a day. With regards to taking a supplement, the Department of Health recommends breastfed babies be given a daily supplement of 8.5 to 10mcg each day (formula-fed babies don’t need it, as formula milk is fortified with vitamin D), and children aged one to four be given a daily supplement containing 10mcg. Adults should take the same amount from October through to the end of March – from then until the end of September, most people should get all the vitamin D they need from
‘There are enormous health benefits from the sun, but it has its dark side – 15 mins of modest exposure is enough’
sunlight, according to the NHS website.
“Those particularly at risk of vitamin D deficiency include pregnant and breastfeeding women, people who work shifts or long hours, and those who cover most of their skin when outside (perhaps for religious reasons),” says Bond, who suggests also eating vitamin D-rich foods including oily fish, cod liver oil, full fat milk, eggs, mushrooms and yogurt.
As for supplements, according to a recent report, the UK spends £7million on vitamin D supplements each year. Banwell says that vitamin D3 appears to be the best – whether in spray, dropper or tablet form – and is the one he recommends his patients take daily.
There are five types of vitamin D, but the body primarily uses plantbased vitamin D2 and D3, which are found in animal products. The latter is more easily converted in the body, and a 2017 study from the University of Surrey found vitamin D3 is twice as effective as D2 in raising overall levels of vitamin D in the body. D3 can also help create calcium and protect against fractures and osteoporosis.
As for the sun, how best to strike the right balance? “While there are immense health benefits from the sun, it has its dark side,” says Banwell. “Fifteen minutes of unprotected sun exposure every day is sufficient, and comes with a psychological benefit too.” People with darker skin tones take longer to make vitamin D (although they should still be cautious of burning) and the more skin you expose, the less time you need in the sun.
Most experts advocate “sun micro-dosing” – enjoying short bursts of sunshine rather than longer periods of exposure, which can increase your risk of burning, especially if you’re fair skinned. “The concept of micro-dosing sun exposure is a more attractive one as it limits the risk of sunburn,” says Banwell. “However, ultimately, cumulative sun exposure is directly proportional to skin cancer risk. The intensity of the UV radiation is also important, hence the significant risk of sun beds and tropical climates.
“What’s really interesting is the new generation of sun screens coming out of Australia that contain vitamin D precursors. One, called Rationale, has SPF in it to protect skin, but it’s also light activated so UV rays are turned into vitamin D in the body. Up until now, products like this have only been available in medical spheres,” and aren’t yet available to consumers, but watch this space.
Banwell advises a “5:2 approach to vitamin D – five parts good quality supplements, and two parts moderate, modest sun exposure. Along with a good vitamin-rich diet, this will ensure you get just the right amount to stay healthy all year.”