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): ##STR00001## in which n=0, 1 or 2, R.sub.1=OH, OCOR.sub.3, OPO.sub.3H.sub.2, OPO(OR.sub.4)(OR.sub.5), or OR.sub.6, R.sub.2=OH, R.sub.3, or NHR.sub.7, R.sub.3=particularly alkoxyl (C.sub.1-C.sub.26), ceramide 1, ceramide 2, ceramide 3, ceramide 4, ceramide 5, ceramide 6a and 6b, S-cysteinyl, or S-glutathionyl, carnitoyl, lipids, polyols, OR.sub.4=OR.sub.5=particularly alkoxyl (C.sub.1-C.sub.26), ceramide 1, ceramide 2, ceramide 3, ceramide 4, ceramide 5, ceramide 6a and 6b, S-cysteinyl, or S-glutathionyl, carnitoyl, lipids, polyols, OR.sub.6=pyruvate, lactate, citrate, fumarate, maleate, myristate, palmitate, stearate, palmitoleate, oleate, linoleate, natural fatty acids, or 13-cis retinoate, R.sub.7=H, alkyl, natural amino acids, or natural amines.