This week in the UK we’ve been experiencing a heat wave which has left many sweltering in the sun and seeking any available shade. We all know the dangers of sun exposure to our skin but we perhaps overlook the important benefits that it provides through vitamin D synthesis.
Vitamin D is important for the body in several ways and possessing inadequate amounts has been linked to autoimmune conditions; metabolic, respiratory, cardiovascular and psychiatric disorders; as well as cancers and osteoporosis.
We can obtain vitamin D through our diets but an estimated 90% is produced endogenously in healthy adults. To do this our bodies synthesize vitamin D from solar ultraviolet B radiation, making sunlight an essential factor in obtaining recommended vitamin D levels.
Vitamin D deficiency
Vitamin D deficiency is prevalent worldwide and even those in sunny locations are at risk of being deficient. Modern occupations trending towards indoor work are likely to play a big role in this as decreased time spent outdoors would be expected to lead to decreased vitamin D levels.
In order to more fully understand the role that occupations play on vitamin D levels and identify those groups at the greatest risk, researchers at the University of Alberta, Canada performed a systematic review of 71 papers with large population based cohorts that defined occupational groups.
Vitamin D deficiency was most prevalent in shift workers (80%) closely followed by indoor workers (77%) and healthcare students (72%).
It was found that across all occupational groups, serum 25-(OH)D levels (a measure of vitamin D status in individuals) were below recommendations for optimal levels that are recommended by the Endocrine Society.
Vitamin D deficiency was most prevalent in shift workers (80%) closely followed by indoor workers (77%) and healthcare students (72%). Deficiency levels for practicing physicians, nurses and a group termed ‘other healthcare employees’ were all below 50%.
The findings of the study are consistent with an assumption that workers in an indoor environment would display lower levels of vitamin D compared to those working in outdoor environments.
The author’s state that the high prevalence of vitamin D deficiency in healthcare students and medical residence (72% and 65% respectively) could be due to long working hours combined with additional time spent studying, leading to considerable time spent indoors. This is an alarming find given low vitamin D in young adults may decrease bone density, increasing the risk of osteoporosis later in life.
Perhaps the most worrying statistic is the high levels of vitamin D deficiency seen in shift workers. This deficiency has previously been suggested to be associated with shift workers’ predisposition for musculoskeletal, cardiovascular diseases and cancer. However drawing conclusions on this is complicated given that shift workers may work at various times of the day and may spend more time in daylight outside of conventional working hours.
Clinical implications
For predominantly indoor occupations such as office work, more encouragement could be given to employees to take breaks outside.
Given the high prevalence vitamin D deficiency in shift workers, the authors call for regular screenings of these and other high risk groups to be considered in future clinical practice guidelines. They also call for education on the importance of healthy vitamin D levels, both through sun exposure and dietary intake, to be incorporated into workplace wellness programs.
For predominantly indoor occupations such as office work, more encouragement could be given to employees to take breaks outside, giving their skin more exposure to UV light. This could be aided by revised work schedules allowing for such breaks.
So whether you’re parked by a fan in the midst of a heat wave or confining yourself to an office all day, provided that you avoid excessive exposure, it may be a good idea to venture outside and soak up some sun.
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