Updating usermeta for a custom meta_key

I am using MB User Profile to have users submit their forms on the front end. This works with updating the default fields like first_name and description. However, it does not update metadata for custom fields. I want users to be able to select from a list of categories so I can show them custom content based on their interests.

If I add this, it will create/update usermeta for premium_categories when I save a profile in the admin area.

add_action( 'personal_options_update', 'save_premium_categories' );
add_action( 'edit_user_profile_update', 'save_premium_categories' );

function save_premium_categories( $user_id ){
    if ( !current_user_can( 'edit_user', $user_id ) ) { return false; }
    update_usermeta( $user_id, 'premium_categories', $_POST['premium_categories'] );
}

However, it still does not update when I save on the front end. Any ideas how I can make this work?