In fact, if you don’t get enough sunlight in your daily ‘light diet,’ you can suffer deficiency symptoms, such as:

• seasonal depression (also known as Seasonal Affective Disorder)
• poor quality of sleep
• a loss in work performance (especially in night-shift workers)
• disrupted melatonin regulation
• depressed cortical brain activity
• depressed immune function

Unfortunately, the light to which most of us are exposed each day comes from manmade sources, such as fluorescent, sodium and incandescent lights that do not produce full-spectrum sunlight. Numerous studies have shown that these limited-spectrum artificial light sources can make students irritable in school, reduce production among factory workers and make office workers sluggish. In one study, researchers even found that calcium absorption dropped off in the elderly who spent their days indoors during the winter, while those who spent time under full-spectrum lighting had an increase in calcium absorption.

Getting enough full-spectrum light can give your mood a tremendous boost. Light can help reduce stress, help you feel happier and improve your ability to concentrate. To make sure that you are getting enough light in your diet, doctors recommend the following tips:

• Try to spend at least 15 minutes outside every day; even when it’s very cloudy. The full-spectrum daylight is still beneficial to your health.

• Begin using a light box during the fall and winter seasons, especially if you tend to get the winter blues.

• Stop wearing sunglasses as they create very unnatural light for your eyes. Sunglasses should only be worn when you need to protect your eyes from physical harm or very bright light.