The amount of UV exposure needed to maintain vitamin D levels depends on the time of year, location, skin type, day-to-day activity and individual circumstances.
Vitamin D levels can vary naturally throughout the seasons. During winter when UV levels are lower and most people are more likely to cover up and spend more time indoors, vitamin D levels will also be lower. In summer, UV levels are high and people are more likely to be active outdoors, so most people's vitamin D levels will also increase.
The body can only store a limited amount of vitamin D at a time. Once a person has received enough UV exposure, spending more time in the sun won't increase vitamin D levels any more – but will increase the risk of skin cancer. How much UV exposure a person needs depends on the time of year, UV levels, skin type and whether or not they are at risk of a vitamin D deficiency.
May to August in Victoria
From May to August in Victoria, sun protection is not recommended unless:
- you are near highly reflective surfaces such as snow
- you are outside for extended periods or an outdoor worker
- UV levels reach 3 or higher.
For vitamin D levels, spend time outdoors, with some skin uncovered, around noon each day. Being physically active outdoors will also help the body to make vitamin D.
Outdoor workers have extended periods of sun exposure and therefore it is unlikely that vitamin D deficiency is an issue for this professional group. It is recommended that outdoor workers use sun protection measures throughout the year regardless of UV levels, as they have an increase risk of skin cancer.
September to April in Victoria
From September to April in Victoria, UV levels regularly reach 3 or higher. This is high enough to damage unprotected skin and increase the risk of skin cancer. At this time of year, all Victorians should Slip, Slop, Slap, Seek and Slide during the daily sun protection times – even those diagnosed with vitamin D deficiency.
Most people make enough vitamin D in summer because UV levels are high and more time is spent outdoors. During these months, most Victorians need just a few minutes of mid-morning or mid-afternoon sun exposure for their vitamin D needs, and should be extra cautious in the middle of the day when UV levels are most intense.
Sunscreen use should not put people at risk of vitamin D deficiency. When sunscreen is tested in laboratory conditions it has shown to block vitamin D production, however regular use in real life shows little effect on vitamin D levels. This is probably because people who use more sunscreen spend more time in the sun, so they naturally have higher vitamin D levels.
Use the free SunSmart app to help remind you when you do and don't need sun protection each day.