As the calendar year comes to an end, many employees who work for companies where vacation time cannot be rolled over will likely lose a chance to escape. They'll have justified leaving time on the table over concerns they could be replaced or laid off. But in reality these employees may be doing themselves more harm than good.

A recent survey of nearly 500 HR professions by the Society of Human Resource Management suggeststaking vacation time actually drives higher employee performance and productivity, boosts organizational morale, contributes to employee wellness and results in higher employee retention.

It can also help a company's bottom line.

"The point is that time to renew fuels productivity rather than undermining it," said Tony Schwartz, CEO of The Energy Project, a group working to change the way the world works.

Here are some of the major findings in the executive summary of "Vacation's Impact on the Workplace" compiled by the Society for Human Resource Management:

n Employees who take most or all of their vacation time are more productive and happier in their jobs than those who do not. Nearly eight in 10 of the human resource managers said taking advantage of available vacation time improves employee job satisfaction.

n Taking more vacation time often boosts employee performance. Seventy-two percent of SHRM members surveyed agreed that if employees who are currently taking less vacation were to take more, they would be more productive.

n Employees are still leaving time on the table. Six in 10 organizations reported that their employees failed to use an average of three or more days of paid vacation each year.

n Human Resource professionals working at organizations with "use it or lose it" policies report higher rates of productivity and greater employee retention than firms with rollover policies. Seven in 10 respondents in organizations with a "use it or lose it" policy believe that employees who take all of their vacation will stay with their jobs longer, while more than half of those with rollover policies agree.

Groups such as the Travel Industry Association have also been working in recent years to promote the idea of vacations being an important part of a healthy lifestyle. Yet even travel professionals sometimes find it difficult to get away for fun.

Asked in a recent interview whether he had used all of his 2013 vacation time, for example, Visit Salt Lake president and CEO Scott Beck smiled and said, "regretfully no."