Active B12 Test Market Size and Forecasts (2021 - 2031), Global and Regional Share, Trends, and Growth Opportunity Analysis Report Coverage: By Diagnosis ( ELISA Assay, Enzyme Immunoassay, Others ); Indication ( Folate Deficiency Anemia, Pernicious Anemia, Macrocytic Anemia, Others ); End User ( Hospitals, Medical Laboratories, Clinical Research Organization, Others ), and Geography (North America, Europe, Asia Pacific, and South and Central America)