Final answer:
Adequacy, deficiency, or excess of nutrient concentration is determined by the availability of nutrients.
Step-by-step explanation:
Whether a nutrient concentration is adequate, too low, or too high is determined by the availability of nutrients. Nutrient density refers to how much of a given nutrient a particular food provides, relative to the mass of the food or the number of Calories it provides. When the nutrient concentration is low, it affects growth in a consistent, often linear way. However, as the nutrient concentration increases, the increases in growth diminish, eventually leading to saturation and no further increase in growth.