add_action( 'show_user_profile', 'my_show_extra_profile_fields' );
add_action( 'edit_user_profile', 'my_show_extra_profile_fields' );

function my_show_extra_profile_fields( $user ) { ?>

	<h3>Fileira</h3>

	<table class="form-table">

		<tr>
	<th><label for="fileira"><?php _e('Fileira'); ?></label></th>

	<td><input type="text" name="fileira" id="fileira" value="<?php echo esc_attr( get_the_author_meta( 'fileira', $user->ID ) ); ?>" class="regular-text" /></td>
</tr>

	</table>
<?php }
add_action( 'personal_options_update', 'my_save_extra_profile_fields' );
add_action( 'edit_user_profile_update', 'my_save_extra_profile_fields' );

function my_save_extra_profile_fields( $user_id ) {

	if ( !current_user_can( 'edit_user', $user_id ) )
		return false;

	/* Copy and paste this line for additional fields. Make sure to change 'twitter' to the field ID. */
	update_user_meta( $user_id, 'fileira', $_POST['fileira'] );
}