enter text with single quote in database using wpdb

Following code truncates every string that has a single quote in it. I tried with and without stripslashes, tried stripslashes_deep but none of them works. If for example name is “Mac Donald’s” its saved as “Mac Donald” and simply cut off where the single quote is.

foreach ($_POST as $key => $value)  
{
    $$key = stripslashes($value);
    echo $key."--".$$key."<br>";

}

$wpdb->update("x_data",array('name'=>$d_name,'address'=>$address,'city'=>$city,'state'=>$state,'postalcode'=>$postalcode,'phone'=>$phone,'fax'=>$fax,'email'=>$email),array('uid' => $user_ID,'id'=>$gid)); 

Any help appreciated