A recent study published in the Journal of Occupational and Environmental Medicine (Plotnikoff, Finch, & Dusek, 2012) revealed that vitamin D levels predict employees’ productivity levels. Using an impressive sample of over 10.000 health care workers, the study demonstrated that employees with low blood levels of vitamin D (below 20 ng/mL) were significantly less productive at work compared to employees with higher levels (over 40 ng/mL). Employees who had low vitamin D levels reported to a higher extent that they come to work but are unable to perform their tasks and duties (i.e. presenteeism), because they experienced low energy levels and reduced focus. As such, these unproductive workers were a liability for their company, who suffered average losses of 112 $ per employee (or a total of $2.3 million for this employer) annually due to presenteeism.

Furthermore, it is likely that employees who are chronically unproductive at work become stressed, frustrated or angry. People with low vitamin D levels may feel powerless and unable to cope with their increasing workload. Feeling chronically underprepared to cope with one’s workload may lead employees to believe that perhaps they do not possess the right abilities and skills to deal with their job demands (i.e. low self-efficacy). Over time, employees with low coping ability beliefs may  take prolonged medical leave, receive negative job performance evaluations or may even lose or quit their job.

Traditionally, vitamin D was considered important only for the absorption of calcium and for bone health, but recent research reveals that the “sunshine vitamin” is much more important than previously thought, and has an essential role in a person’s overall health and energy level. More specifically, healthy levels of vitamin D help fight cancer, heart disease, autoimmune diseases and a variety of mental illnesses, including depression. Researchers agree that preventing vitamin D deficiency is not only important in jobs that involve physical activity, but overall for promoting optimum functioning of employees, regardless of their job demands.

New empirical studies reveal that vitamin D deficiency is extremely widespread among working samples, and can vary from 30% (Plotnikoff et al, 2012) to over 70% of the employees (Jeong et al, 2014). Data from a Korean sample showed that Vitamin D deficiency was correlated with working conditions such as working in shifts, working indoors or working in an office. Workers who have limited opportunities to receive direct sun exposure (minimally on hands and head) between 10 am and 3 pm are predisposed to vitamin D deficiency. Moreover, people with low vitamin D levels are likely to live in high latitude regions, such as The Netherlands, where, at 52° N, they are deprived of adequate levels of sunshine for more than half a year. Furthermore, people with naturally darker skin or workers who come from warmer areas (and tend to wear more clothes in the Dutch climate) are especially prone to vitamin D deficiency. 

This new interdisciplinary research could help managers understand why their employees may be lethargic or overly tired at work. Particularly in cases where there are no other apparent causes for dramatic decreases in productivity over the winter months, managers should consider if their employees have adequate levels of vitamin D. However, this does not mean that managers should start chasing after their employees to take blood samples. Company health programs should provide employees with minimal information about the importance of avoiding vitamin D deficiency and ways to prevent it. In addition, simple lunch break walks outside can be beneficial and should be promoted.

(Elena) Martinescu, studies why and how people spread gossip in the workplace, and how they interpret and react to gossip about themselves or their co-workers.

She will defend her PhD thesis on June 19, 2017: “A functional perspective on the self-relevance of gossip for senders, receivers and targets.”

References:

Plotnikoff GA, Finch MD, Dusek JA (2012) Impact of vitamin D deficiency on the productivity of a health care workforce. J Occup Environ Med 54:117–121.

Lee DM, Tajar A, O’Neill TW et al (2011) Lower vitamin D levels are associated with depression among community-dwelling European men. J Psychopharmacol 25:1320–1328

Hatun S, Islam O, Cizmecioglu F, et al.  (2005). Subclinical vitamin D deficiency is increased in adolescent girls who wear concealing clothing. J Nutr. 135:218–222.

Campagna AM, Settgast AM, Walker PF, DeFor TA, Campagna EJ, Plotnikoff GA. Effect of country of origin, age, and body mass index on prevalence of vitamin D deficiency in a US immigrant and refugee population. Mayo Clin Proc. 2013;88(1):31–37.

Jeong H, Hong S, Heo Y, Chun H, Kim D, Park J, Kang MY (2014) Vitamin D status and associated occupational factors in Korean wage workers: data from the 5th Korea national health and nutrition examination survey (KNHANES 2010-2012). Ann Occup Environ Med. 16;26:28.