. "vitamin precursor; a substance that is converted into a vitamin in animal tissues"@en-us . . . . "0"^^ . "15090379-n"^^ . "114235742"@en-us . . "vitamin precursor; a substance that is converted into a vitamin in animal tissues"@en-us . . . "provitamin"@en-us . . "115090379"^^ . . "0"^^ . "provitamin"^^ .