Cod liver oil - a potentially toxic source of Vitamin A: Hypervitaminosis A can result from ingestion of too much vitamin A from diet, supplements, or prescription medications.
This visible light region consists of a spectrum of wavelengths that range from approximately 700 nanometers (abbreviated nm) to approximately 400 nm. Expressed in more familiar units, the range of wavelengths extends from 7 x 10 -7 meter to 4 x 10 -7 meter.
Physicists often refer to it as visible light. The electromagnetic spectrum, shown in Figure 12.1, includes the energy emitted at all wavelengths. This includes radio waves, microwaves, infrared rays, visible light, ultraviolet rays, X-rays, gamma rays, and other electromagnetic radiation of longer and shorter wavelengths.