This invention relates to compositions, methods and kits for determining the presence and/or amount of vitamin D analytes, including vitamin D isomers, and metabolites thereof in a sample suspected of containing the same. Compounds include compounds of the Formula I, namely, (R1)p-(L)q-Z wherein R1, L, p and q are as defined herein. These compounds are capable of binding specifically to corresponding antibodies. Compounds and antibodies in accordance with the principles described herein can have therapeutic activity. These compounds may be administered in therapeutically effective amount, which is an amount to provide treatment of a particular disease state associated with vitamin D. Administration of the examples of compounds in accordance with the principles described herein can be by means of any of the accepted modes of administration for agents that serve similar utilities.