We're constantly being told to wear sunscreen to protect ourselves from skin cancer and ageing, but by avoiding sun exposure, could we be doing ourselves more harm than good?
Exposure to UVB rays provides more than 90% of our vitamin D production but wearing a sunscreen with an SPF as low as eight reduces the skin's production of vitamin D by an incredible 95%.
Vitamin D has many important roles in the body. It regulates calcium and therefore is essential for strong and healthy bones and teeth. It's necessary for healthy functioning immune and cardiovascular systems and for healthy cognitive function to name just a few.
Vitamin D deficiency is more common than we think. Between 2001-2004, an astounding 70% of Caucasian Americans and 90-95% of African Americans were estimated to have insufficient vitamin D levels. As with many things that America do, Britain aren't far behind. I regularly test my client's vitamin D levels. Of the last 20 clients that I have tested, six were deficient, six had suboptimal levels and just eight had optimal levels. Those with optimal levels were usually either supplementing, or spent a significant amount of time abroad.
For a long time we have been aware of the impact of severe Vitamin D deficiency which manifests as rickets. A disease of the 19th Century, rickets was virtually eradicated half a century ago, however, there has been a re-emergence of the disease in recent years. Aside from rickets, evidence links vitamin D deficiency to a wide range of different health concerns. These include autoimmune diseases, cancer, cardiovascular disease, depression, dementia, infectious diseases, musculoskeletal decline, and more.
Vitamin D deficiency symptoms can include lower back pain, muscle weakness and and throbbing bone pain. More subtle signs of vitamin D deficiency may include fatigue, muscle aches and pains and an increased susceptibility to infection. However it's perfectly common to have suboptimal levels of vitamin D and experience no symptoms at all.
Interestingly, the darker a person's skin type, the lower their ability to synthesise Vitamin D. In a modern world where migration is common, people whose skin type have adapted to prevent excess vitamin D synthesis in their native, sunny environment are particularly prone to deficiency when living in a sun-deprived country such as the UK. My client list comprises a diverse ethnic background. My South Asian clients with darker skin are commonly deficient. Muslim women who cover themselves for religious reasons are also often found to be Vitamin D deficient. That said, I have also seen plenty of Caucasian clients with low, or borderline vitamin D levels. Most of us spend a significant proportion of our time indoors meaning that regardless of skin type, anyone can be affected.
There's no doubt that most of us could benefit from spending a little less time indoors and a little more time outside. Making a conscious effort to tear ourselves away from a screen and get out for a short daily walk could improve our health and wellbeing in many ways. As with many things in life, the key to safe, Vitamin D promoting sun exposure is moderation. The NHS website advises short, 10 – 15 minute, daily periods of sun exposure without sunscreen during the summer months. However it recognizes that it's particularly hard to achieve optimal levels during winter months and that supplementation may be necessary.
That said many of us use a daily sunscreen as part of a skincare regime and in doing so could be inadvertently reducing our ability to synthesis vitamin D from the sun. Therefore it's a good idea to take a daily vitamin D3 supplement throughout the year.
How to optimise your vitamin D levels:
- Know your vitamin D level. This can be arranged for you using a simple blood test.
- Expose your skin to the sun daily. If applying sunscreen to the face, expose your arms (but of course – at a level that doesn't cause redness or burning).
- Eggs (organic or at least free range) and wild oily fish provide a source of vitamin D as well as providing protein and a number of other essential nutrients. I recommend including these foods in your diet regularly.
- Take a vitamin D3 supplement at a dose to suit your needs.