Nutrient essence   Nutrient essence is also referred to as acquired essence. It is derived from foods and is necessary for the constitution of the human body and for the maintenance of health and physical activities. It can be converted to essence, an essential substance needed for reproduction that is stored in the kidneys.		shui gu jing wei 水谷精微   水谷精微又稱後天之精 是由飲食經脾胃轉化生成。是構成人體，維持機體健康和勞動力所需的營養物。中醫認為它可轉化作生殖之精即後天之精並貯藏在腎臟。