This high - protein formula is grain - free and is packed with antioxidants and complex carbohydrates to help support immune system health and keep your dog's tummy healthy. (mysweetpuppy.net)
There's a lot of buzz about vitamin D for immune system health including flu prevention and even treatment. (holisticsquid.com)
As long as you keep the sugar and fat to a minimum, unsweetened cocoa, and cocoa powder may play a role in immune system health. (verywellfamily.com)