Vitamin D and Skin Cancer Protection
Australia has the highest incidence of skin cancer in the world. This is because the paler skinned European migrants, who form the majority of the population, are simply not adapted to Australia’s high UV light levels. Their skin becomes damaged very rapidly unless it is protected by clothing, sun block and shade seeking behaviour.
As the ‘cover up in the sun’ message has been more widely promoted concerns have been raised that this will lead to widespread vitamin D deficiency in the population.
What is Vitamin D?
Vitamin D or cholecalciferol is a natural body chemical which is essential in calcium metabolism and the production of healthy bones. A severe deficiency in children can lead to ‘rickets’ where the bones lose their rigidity and deform. Fortunately rickets is now very rare, as is the adult form ‘osteomalacia’. However ‘osteoporosis’, in which the bones become more porous and brittle as people age, is widespread. A persistent deficiency in Vitamin D is one of the causes of osteoporosis.
Where do we get Vitamin D from?
The majority of vitamin D is manufactured in the skin on exposure to UV light. It is also absorbed from certain foodstuffs such as oily fish but usually not in sufficient quantities to be significant.
Unfortunately the same wavelength of UV responsible for Vitamin D production also causes damage to the DNA of skin cells and increases the risk of skin cancers.
Won’t I get Vitamin D deficient if I wear sun screen and cover my skin with clothing?
No! not usually. For white skinned people all that is required to maintain vitamin D levels is 5-10 minutes of ordinary daylight 3 times a week to the arms and face. This time increases over winter in Victoria and for darker skinned people. There is absolutely no benefit in leaving unprotected skin in the sun for hours on end as nearly all of the vitamin D manufacture occurs in the first 10 minutes or so of exposure. There is absolutely no reason to get sun burnt trying to keep up vitamin D levels.
Who is most at risk of Vitamin D deficiency?
People who don’t get outdoors much during the day – rest home residents with poor mobility for example or night shift workers. People with darker skin types who wear a lot of covering clothing – women from Middle East countries or India for example.
How do I know if I am Vitamin D deficient?
Your Vitamin D levels can be checked with a simple blood test. Your GP can arrange this or I can arrange for this to be done here.
What do I do if I am Vitamin D deficient?
Try to increase your dietary intake of Vitamin D in foods such as sardines, salmon, tuna, herring or mackerel. Other sources include meat, milk, eggs and margarine is fortified with Vitamin D (but in very low amounts).
If your UV exposure is not up to 10 minutes a day to the face and arms 3 times a week try to increase it to this level. There is no point in increasing sun exposure beyond this however and this will increase the long term risk of skin cancer significantly. Brief daily sun exposure is much better than irregular long periods in the sun.
If you are deficient the best way of getting Vitamin D is oral supplement tablets readily available at any pharmacy at reasonable cost. Buy the plain Vitamin D 1000 iu tablets. The initial dosage of these supplements is often significantly higher than recommended on the labelling. Your doctor will advise.
After a few months have your vitamin D blood levels rechecked to ensure your levels have returned to normal. Then check them again once a year together with any other routine blood tests you may have.