Instruct: Classify Amazon reviews into positive or negative sentiment
Query: A Valuable Guide to Wellness

PNH has always been one of the most responsible reference guides to nutrition. Having had formal training in nutritional supplements and holistic remedies, and having seen the benefits of many nutritional supplements, I really appreciate this new expanded 4th Edition. While it is not a substitute for individualized medical care, it can be very informative. I highly recommend it to everyone.