We need Vitamin D for strong bones and general health. It may also protect against cancers and some auto immune conditions such as multiple sclerosis.
Sunlight is the best source of Vitamin D. This means some ultraviolet radiation (UVR) exposure is necessary for vitamin D production. A balance is required between avoiding an increased risk of skin cancer and maintaining adequate vitamin D levels. Sensible sun protection behaviour should not put people at risk of vitamin D deficiency. During the daylight saving months most people get enough UVR exposure to achieve adequate vitamin D levels through incidental sun exposure outside peak the UVR times of 10am - 4pm.
The Cancer Society recognises both the very real benefits - and the risks - of sun exposure. Because of this, we are very specific about the hours we advise sun safety.
Schools need to promote sun protection during peak ultraviolet radiation (UVR) periods, when the ultraviolet Index (UVI), which measures the intensity of the ultraviolet radiation (UVR) in the environment, is 3 or above. This is especially important when spending long periods in the sun, particularly for those with fair skin. In most parts of New Zealand, peak UVR times are between September and April, particularly between 10am and 4pm (during daylight saving hours). However, in some parts of New Zealand, such as Northland, the UVI is 3 or above for longer periods of the year.
Sensible sun protection in daylight saving months should not put people at risk of vitamin D deficiency. Someone who burns easily in the sun may only need 5 minutes of daily summer sun exposure, while someone who tans more easily or has darker skin will need more time e.g. up to 20 minutes. It is likely that in the future, recommendations will become more specifically related to skin type, and length of time in the sun.
While sun protection is not generally necessary in winter months, people should protect themselves if at high altitudes or in snow.
The Cancer Society message is, “a balance is required between avoiding an increased risk of skin cancer and maintaining adequate vitamin D levels.” In recognition of the importance of the Vitamin D issue, the Cancer Society is continuing to review new and emerging research in this area.