Vitamin D Function

Taking more vitamin D is not always enough when cofactors, gut absorption, bile, insulin resistance, or receptor function are impaired. Blood vitamin D levels may not reflect adequate vitamin D effects inside cells. Vitamin D status depends on absorption, activation, receptor function, gut health, insulin sensitivity, inflammation, and nutrient cofactors, not only intake. Vitamin D can be present in blood without producing expected biological effects if supporting factors are deficient or blocked.