For many nutrition deficiencies, a direct cause and effect of different symptoms and diseases has been established. These are known as primary nutritional deficiencies. Secondary deficiencies occur when the vitamin or nutrient requirement may be increased, such as in patients who have pernicious anemia who lack the intrinsic factor needed to absorb vitamin B12. Less well recognized are the effects of nutritional deficiencies on chronic disease, especially acute and chronic neuromuscular diseases. This article identifies some of the causative factors and provides the reader with a guideline for what to consider in the evaluation of individuals who have neuromuscular problems. The context of these disorders is best understood on a foundation of basic nutrition information.