Definition of "deficiency" []

• The quality or condition of being deficient; incompleteness or inadequacy. (noun)
• A lack or shortage, especially of something essential to health; an insufficiency: a nutritional deficiency. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "It has been demonstrated that a blood protein deficiency is the cause of this inherited illness."
• "Protein deficiency is common in children (43% of children five years of age or less) resulting not only in a high mortality rate but irreversible mental retardation and restricted body development in survivors."
• "The best vitamin E form for preventing or reversing this deficiency is the liquid form: tocopheryl polyethylene glycol 1000 succinate (TPGS), because the body absorbs it more readily."