Dr Harryono Judodihardjo, medical director of the Cellite Clinic in Cardiff, discusses how to find the middle way between keeping safe in the sun and getting enough vitamin D. This article appeared in the Western Mail in April 2014.
A great deal of confusion has been generated by the debate over staying safe in the sun, and fulfilling the body’s need to generate vitamin D via exposure to ultraviolet light.
As we well know, too much sun damages the skin, causing coarse wrinkles, sagging and age spots, as well as increasing the risk of potentially life-threatening skin cancers.
Vitamin D, on the other hand, is essential for the formation and maintenance of strong and healthy bones and perhaps even prevents some cancers.
It seems, on the face of it, to be a no-win situation – I can either protect my skin or my bones.
However, the situation need not be this polarised.
It’s worth noting that the amount of time in the sun needed to make enough vitamin D is relatively short.
The time needed also varies according to one’s skin colour – for fair skinned individuals it’s typically short – far less than the amount of time that makes skin redden or burn. In fact, it should be enough to regularly go outside for a matter of minutes without sunscreen. Darker skinned people need slightly extended periods in the sun to generate the same levels of Vitamin D.
People who cover up completely, for example, for religious reasons, may also need to address the amount of Vitamin D they are receiving.
When it comes to sun exposure for all skin types, little and often is best. In the summer months this can be achieved by carrying out normal routine activities, such as cycling to work, or walking to the shops. Once the skin has made its quota of vitamin D for that day it will stop producing it. Longer UV exposure after that will not produce more vitamin D but just cause skin damage.
By taking steps to avoid burning, people can achieve a balance between reducing the risk of skin cancer and premature ageing, and enjoying the beneficial effects of the sun.
Particular risk groups need to pay special attention to protecting their skin, for example, those who are fair-skinned, have lots of moles and freckles or have a family history of skin cancer, need to use high-factor sun protection to reduce their risk of skin cancer. Sensible sun protection shouldn’t prevent the production of sufficient vitamin D.
For prolonged exposure, and for protection when the sun is at its strongest, that is, during the middle of the day from around 11am-3pm, then it’s important for everyone to use a high SPF sun screen, and wear a hat and sunglasses with proper UV protection.
I would recommend brief periods of exposure before the sun becomes too fierce thus allowing the skin to synthesise vitamin D via UV light without risk of burning. The newly created vitamin D then travels through the body and is hydroxylated first in the liver, and then in the kidneys, from which point it can be used to help protect our bones.
During the winter, when UV light diminishes, as it has during the especially rain-swept start to 2014, some people may need to boost their vitamin D intake with supplements such as cod liver oil.
The sun is not our only source of vitamin D – we also get much of it from our diet.
Certain foods, such as milk and many cereals, are fortified with it.
Some foods are naturally rich in the vitamin. These include egg yolks, liver and oily fish such as salmon, tuna, mackerel and sardines.
Cooking methods may also impact on vitamin D levels in food, and it’s thought that baking fish rather than frying it is the best way to maintain its vitamin content.
Vegans need to look carefully at their diet, and ensure that the products they are buying, such as tofu and soy milk, have been fortified.
The amount of vitamin D we need to maintain good bone health increases as we age, as our bodies require greater protection against diseases such as osteoporosis, where the bones become thin and fragile, and fracture more easily.
Pregnant women also need to make sure that they are getting enough vitamin D.
As with most things, a sensible middle way can be established where individuals practise sun safety by avoiding over-exposure, using high-factor sun protection creams and wearing a hat, but also pay attention to eating a diet rich in Vitamin D and enjoying sunshine in moderate amounts.