Get Meta Keyword By ID in Magento

I want to display Meta Keyword of a Product in view.phtml file. What function do i need to call upon to display meta keyword of that particular product in Magento.

To return the meta keyword of the rendered product, use following within your view.phtml:

<?php echo $_product->getMetaKeyword(); ?>

You can get meta keyword by product id with:

<?php $_product = Mage::getModel('catalog/product')->load($productId); ?>
<?php echo $_product->getMetaKeyword(); ?>