Vitamin D – to tan or not to tan?

We have listened and we have slapped on large quantities of sunscreen to protect ourselves from our hot New Zealand sun.  But the information has again become cloudy and less defined.  Now we are being told that we should actually be getting some sun on our skin – to prevent the risk of becoming Vitamin D deficient.  We have listened so well that studies done in New Zealand have suggested up to 48% of us may have deficiencies.  So what is the message about sun protection now?  Do we tan or do we not tan? 

What is vitamin D?

Vitamin D is a hormone that is required for everyday health assisting in calcium and phosphate absorption.  It has a role in healthy bones (preventing rickets and osteoporosis), joint, muscles and nerve function.  There is evidence to suggest it may reduce the risk of cancers (including melanoma, ironic perhaps), heart disease and benefit our immune system.  Those of us who struggle through winter will know that Vitamin D is important in preventing seasonal depression and sleep disorders.

 Vitamin D is produced by the ultraviolet light (UVB) and our cholesterol in our skin.  It is also found in small qualities in food sources such as oily fish, eggs and meat.  Fortified foods are becoming more common.

 In winter we become more at risk of Vitamin D deficiency, particularly those in the South, older people, those with darker skin and those not willing to go outside.  We are able to store Vitamin D for 30-60 days to help us get through winter.  However, we must have sufficient stores at the end of summer to help us with this.

 How much we need is debated.  It is suggested that we could require between 50 nmol/L to 80 nmol/L.  Also just how much exposure we need to the sun is not clear, nor well studied.  The experts at this stage are unable to provide definitive guidelines, putting it down to the variation in our skin colours, seasonal UV rating and even our location in the country.  They are suggesting that more research is required.

 Current recommendations

• Avoid sunburn
• It is preferable to expose larger areas of skin for shorter periods of time.  Do this without sunscreen on either side of the peak burn time, i.e. mornings and late afternoons.  Do not burn; therefore the exposure time should only be a few minutes.
• We may need to consider using supplements or fortified foods.  Look for foods listing Vitamin D on the packaging.  Dairy foods are often fortified due to their calcium content.  Particularly those at risk should be considering food sources of Vitamin D.  These are the people with darker skinned, those that cover their skin with clothing for religious or ethnic reasons, elderly, house bound people, the obese and during winter. 

So the message is lacking in precise detail.  Vitamin D will be an area of hot debate for some time, until some true clear guidelines can be achieved.  But still remember the most important thing is to avoid sunburn.