MEDLINE is the U.S. National Library of Medicine's (NLM) premier bibliographic database that contains over 18 million references to journal articles in life sciences with a concentration on biomedicine. A distinctive feature of MEDLINE is that the records are indexed with NLM Medical Subject Headings (MeSH).The great majority of journals are selected for MEDLINE based on the recommendation of the Literature Selection Technical Review Committee (LSTRC), a National Institute of Health (NIH)-chartered advisory committee of external experts analogous to the committees that review NIH grant applications. MEDLINE is the primary component of PubMed, part of the entry series of databases provided by the NLM National Center for Biotechnology Information (NCBI). MEDLINE may also be searched via the NLM Gateway (23).
Zinc is a trace metallic element that occurs naturally in the earth. Certain vegetables, meats, and seafood have more zinc content than others. This makes it fairly easy to obtain zinc through a varied diet. An extreme zinc deficiency is rare in the United States, as most people get some zinc through the foods that they eat. However, when levels of zinc fall below the recommended threshold, problems begin.