Provided herein are wearable and/or portable devices for the detection of at least one analyte in a body fluid. In accordance with certain aspects of the present invention, there are also provided methods for the use of invention devices for the automated administration of essential vitamins, minerals or other nutrients to a subject in need thereof. In accordance with the present invention, there are also provided body fluid sampling devices. In certain aspects of the present invention, there are also provided wearable and/or portable devices for the detection of at least one analyte in a body fluid, and the automated administration of essential vitamins, minerals or other nutrients to a subject determined to be in need thereof based on the results provided by the means for detection.
