Sun exposure and 25-hydroxyvitamin D 3 levels in a community sample: Quantifying the association with electronic dosimeters

There is uncertainty about the amount of sun exposure required to increase low blood 25-hydroxyvitamin D (25(OH)D ) levels, a possible disease risk factor. The study aimed to quantify the association between sun exposure and serum 25(OH)D concentrations in a multiethnic community sample (n=502) living in Auckland (37°S) and Dunedin (46°S), New Zealand, aged 18-85 years. They wore electronic ultraviolet dosimeters between March and November (autumn, winter and spring) for 8 weeks to record their sun exposure. This was converted to standard erythemal doses (SEDs), corrected for clothing to generate equivalent full-body exposures, SED . Blood samples were collected at the end of weeks 4 and 8 to measure 25(OH)D . Median weekly SED was 0.33 during weeks 1-4 and 0.34 during weeks 5-8. Weekly exposures