Vitamin D levels in most occupational groups are well below those considered optimal for health, according to a study published in the open access journal BMC Public Health. Shift workers, healthcare workers and indoor workers in particular are at high risk of vitamin D deficiency, researchers at the University of Alberta, Canada suggest. Understanding the prevalence of vitamin D deficiency in different professions could improve public health interventions and prevention efforts.
Dr. Sebastian Straube, the corresponding 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.
In order to evaluate vitamin D levels, deficiency and insufficiency in different occupations and to identify at-risk groups of workers, the authors conducted a systematic review of 71 peer-reviewed journal articles which involved 53,425 individuals in total and spanned a range of latitudes in both the Northern and Southern hemisphere.
The review may be limited by lack of agreement on the definition of vitamin D deficiency, different methodologies for assessing vitamin D levels across the included studies, and studies taking place at different latitudes, although vitamin D deficiency or insufficiency did not seem to be dependent on study location. The authors caution that heterogeneity between studies may make conclusions derived from their combined data less reliable.
Article: Vitamin D levels and deficiency with different occupations: a systematic review, Daniel Sowah, Xiangning Fan, Liz Dennett, Reidar Hagtvedt and Sebastian Straube, BMC Public Health, doi: 10.1186/s12889-017-4436-z, published 22 June 2017.