What is a Functional (or Subclinical) Deficiency?
A functional deficiency encompasses any of the factors that reduce the efficacy of a nutrient. Thus, a given nutrient may be present, but it may not be properly activated, appropriately localized or have sufficient cofactors to function at a normal level of activity. No matter what the cause, the result will be a defect in the biochemical pathways that depend upon that nutrient for optimal function. A deficient or defective pathway may operate at a sub-optimal level for many months, or even years, before a clinical symptom becomes apparent.
