The encyclopedias (and some books) I am listing here are specific to their subject and will provide you a basic introduction to that creed's viewpoints on health and spirituality. You can't know everything, so these encyclopedias will help you understand the perspective(s) from a spirituality other than your own. Where possible, I've linked to the online version of the item.
If you are curious about what others are saying and want to join in that scholarly conversation, the surest way to find scholarship on your topic is to use a database focused on the topic you want. There are several in the area of religion, spirituality, and philosophy and I've listed them below.