PURPOSE: To obtain a compound containing vitamins or hormones in a state having improved stability and water-solubility without causing decomposition of the vitamins, etc., and useful as an injection or health food, by clathrating vitamins or hormones with a cyclodextrin derivative.

CONSTITUTION: A vitamin (e.g. vitamin A, D, E, K, folic acid, etc.), a vitamin derivative (e.g. activated vitamin D2 derivative) or a hormone (e.g. steroid hormone) is added to an aqueous solution of maltosyl cyclodextrin (e.g. maltosyl α-cyclodextrin) and the mixture is optionally heated and stirred to obtain the objective clathrate compound.

EFFECT: A fat-soluble vitamin or hormone (e.g. vitamin D) which has hitherto been used as an injection in the form of emulsion can be utilized in the form of an aqueous solution.