The purpose of this invention is:new selenohydroxy acid compounds and their derivatives;their process for the preparation;use of the new compounds as precursors of L(+)-selenomethionine and / or source of selenium in human or animal nutrition, in cosmetics and pharmaceutics;and nutritional, cosmetic and pharmaceutical compositions containing them.The new compounds that are the subject of this invention satisfy the general formula (I):in whichn=0, 1 or 2,R1=OH, OCOR3, OPO3H2, OPO(OR4)(OR5), or OR6,R2=OH, R3, or NHR7,R3=particularly alkoxyl (C1-C26), ceramide 1, ceramide 2, ceramide 3, ceramide 4, ceramide 5, ceramide 6a and 6b, S-cysteinyl, or S-glutathionyl, carnitoyl, lipids, polyols,OR4=OR5=particularly alkoxyl (C1-C26), ceramide 1, ceramide 2, ceramide 3, ceramide 4, ceramide 5, ceramide 6a and 6b, S-cysteinyl, or S-glutathionyl, carnitoyl, lipids, polyols,OR6=pyruvate, lactate, citrate, fumarate, maleate, myristate, palmitate, stearate, palmitoleate, oleate, linoleate, natural fatty acids, or 13-cis retinoate,R7=H, alkyl, natural amino acids, or natural amines.