Light from the sun – a nutrient that travels at the speed of 186,000 miles a second from a source 93 million miles away and rates with pure food, water and air as a part of the life support system on earth.


We all know that light energy in the form of sunlight is essential for all living things. Sunlight is more than just bright light. Its components are best seen when a rainbow is viewed. We see the different visible colors ranging from Violet, Blue, Green, Yellow, Orange, Pink to Red. In addition, we have the Ultraviolet and Infrared colors that your eyes can’t see. This is referred to as the full spectrum of sunlight.

Sunlight enters your body through your eyes (98%) and through your skin (2%). Sunlight provides energy to all the cells in your body. This is accomplished when the sun’s rays are passed through the eyes, converted by the hypothalamus and other primary glands into electro-chemical energy. This energy is then carried throughout the many distribution systems within the body to reach each and every cell.

How Much Sunlight Do I Need?

Experience shows that the human body needs a minimum of 30 minutes a day and ideally it needs 2 hours of sunlight energy. This will keep the body functioning well and maintain good health. However, it must be renewed daily. You don’t store the sun’s energy. Less than this amount is labeled “light malnutrition or light starvation”. Therefore, during dark winter days, when you are indoors a lot you need exposure to an artificial form of sunlight called Full Spectrum Light which can help supply this missing amount of sunlight. Please refer to the educational brief on Full Spectrum Light. This type of light with a brightness of 2500 lux, used for up to 6 hours over the day, will generally supply the minimum requirement.

SAD (Seasonal Affective Disorder)

“Extensive and prolonged” lack of sunlight can result in a condition called SAD. SAD is a condition characterized by low energy, irritation, and depression. SAD often happens during the winter months when very little natural sunlight is available and the weather keeps people indoors (especially in colder climates and higher latitudes – northern and southern).

Regular exposure to full spectrum lighting has been proven to help alleviate this condition!

For further information on SAD treatment, refer to the SAD discussion in the Full Spectrum Light educational brief section.