Vitamin D3, also known as cholecalciferol, comes from fortified foods, animal foods (fatty fish, cod liver oil, eggs, and liver), supplements, and can be made internally when your skin is exposed to ultraviolet (UV) radiation from the sun. Structurally, these two are not the same.
Definition of mind for Students. 1  1 : the part of a person that thinks, reasons, feels, understands, and remembers. 2  2 : memory 1 Keep my advice in mind. 3  3 : intention 1 I changed my mind. 4  4 : a person's view or opinion about something Speak your mind.
A concept is a thought or idea. It's a general idea about a thing or group of things, derived from specific instances or occurrences. It often applies to a theoretical idea in science: Einstein's contribution to the concept of relativity. A concept is an idea conceived in the mind.