Lights rated at 5,000k and above are considered to be similar to daylight. This provides a number of benefits to human health. The primary benefit is to those that suffer from Seasonal Affective Disorder (SAD), a depressive condition associated with the change in seasons. Other health benefits include the suppression of melatonin secretion and the stimulation of serotonin secretion.
A 1993 study found that the prevalence of SAD at 40° N latitude was 12.5 percent. Bloomington, IL is located at 41° 51′ 0″ N. Thus, it is reasonable to assume that approximately 12 percent of your employees are affected by SAD each year. Light therapy, or exposure to full spectrum lighting (5,000k or above) for at least 90 minutes, is widely used to treat SAD. Most lighting fixtures we install are rated at 5,000k.
Melatonin is a naturally secreted chemical that encourages sleep. It is also synthesized by the ingestion of tryptophan, commonly found in turkey. Melatonin is secreted for a number of reasons, but what is important is that exposure to full spectrum lighting was found to significantly impede melatonin secretion.
Serotonin, on the other hand, is one of the primary chemicals associated with happiness, satisfaction, and alertness. Selective Serotonin Reuptake Inhibitors (SSRIs) are commonly used to treat depression, anxiety, and personality disorders. Full spectrum lighting has been linked to increased levels of serotonin release, making those people happier, more alert, and more satisfied