ABSTRACT
Vitamin deficiencies arise when the diet is inadequate in its content of one or more nutrients or when the body is unable to utilize dietary nutrients adequately. Single nutrient deficiencies are rare these days, because a diet that is suboptimal in one vitamin is nearly always suboptimal in others. Thus, a poor diet tends to have multiple inadequacies. Furthermore, some vitamins are involved in the metabolism of other vitamins, and therefore deficiencies may be interconnected.
