A common question we get asked is: “how am I going to get Vitamin D if I am using sun screen and want to avoid skin cancer?”
There is no evidence that using sun screens lead to vitamin D deficiency [1]. It is more likely that avoiding the sun completely is a cause. For example, being in doors all day and getting no sun exposure.
Ultraviolet B (UVB) from the sun interacts with pre-vitamin D in the skin to produce Vitamin D3.
Once this enters the blood stream, it is further metabolized to active forms (hydroxyvitamin D3) and works as a hormone. So Vitamin D is really a hormone produced using UVB rays rather than a vitamin [2]. It is important in bone health and deficiency can increase the risk of osteoporosis (weak bones).
Most of the Vitamin D we need comes from sun exposure with only about 5-10% coming from foods such as fatty fish (eg salmon), eggs, and some fortified milks and cereals [2]. So, the best source remains sun exposure. But how to get this safely?
Being outside and in the sun makes us feel good. We all know that- there’s nothing better than a sunny day! The good news is that the body can only make so much vitamin D at a time and so we don’t need to be out long to get enough. 10 to 15minutes a couple of days a week is enough.
In summer, avoid the high UV times of the day and go outside for 10-15mins in the morning or later afternoon. Check the UV index with weather apps or SunSmart and use sun screen if the UV index is over 3. In winter, when the UV index is low, especially on Victoria or southern SA, maybe go a brief walk at lunchtime before you go back to work.
We can use sunscreen, get some vitamin D and avoid sun burn and long exposures to the sun that increase our risk of skin cancer.
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