Winter might be creeping around the corner, but there’s good reason to show more skin. This Australian study published in the American Journal of Epidemiology analysed information of over 1000 participants related to sun exposure, dietary sources of vitamin D and use of supplements.

The model employed by researchers explained 40% of differences found in serum D levels. Modifiable behaviours such as physical activity, time spent outdoors and clothing cover accounted for 52% of the explained difference, while 38% was due to environmental factors and 10% demographic or constitutional factors. The single and strongest contributor to the explained differences in serum D levels was the amount of skin exposed. According to researchers, each 10% decrease in clothing cover was associated with a 5, 2 nmol/L increase in serum D level, without increasing duration of sun exposure.

This suggests that a more effective way of increasing serum D levels would be to show more skin by covering less of it, instead of spending more time in the sun.