Dr. Sebastian Straube, the lead author said, "Our results suggest that occupation is a major factor that may contribute to suboptimal vitamin D levels. Regular screening of vitamin D levels in at-risk groups should be considered for future clinical practice guidelines and public health initiatives. Workplace wellness programs could include education about the importance of adequate vitamin D levels. This could help prevent adverse health outcomes linked to vitamin D deficiency, such as metabolic disorders, psychiatric and cardiovascular disorders, and cancer."
The researchers found that prevalence of vitamin D deficiency was highest among shift workers (80% of individuals), followed by indoor workers (77%) and healthcare students (72%). Among healthcare workers, rates of vitamin D deficiency varied depending on whether they were students, medical residents (65%), practicing physicians (46%), nurses (43%) or other healthcare professionals (43%).
Dr. Straube said, "Vitamin D production by the body is reliant on sunshine and UV exposure so any activity that reduces exposure tends to reduce vitamin D levels. Sunlight deprivation in young medical professionals, who may have particularly long working hours, and other indoor workers, puts them at higher risk of both vitamin D insufficiency and deficiency."
A high percentage of indoor workers (91%) were also found to have insufficient vitamin D, which means that their levels of vitamin D weren't necessarily as low as those found in vitamin D deficient individuals, but lower than levels recommended for health. By comparison, 48% of outdoor workers had vitamin D deficiency, while 75% had vitamin D insufficiency.
The authors caution that heterogeneity between studies may make conclusions derived from their combined data less reliable.