On page 565 Glucosamine, N-acetyl (NAG) has a different value as the page 572 NAG. Are they 2 different products?

No, it's the same product. All the usages listed are valid for N-acetyl Glucosamine, also known as NAG.

Related Topics:
Where can I find the most up-to-date values?
In the Blood Type Encyclopedia, on page 488 at the bottom of the page on the left, it lists Co Enzyme Q10: 3 mg. Is that correct, or should it be 30 mg?
Some of the herbs listed as cooking herbs in Eat Right 4 Your Type conflict with the herbs used as medicine in ther Protocols.
The Melatonin dose (200mg) in one of the Encyclopedia Protocols seems a bit high.
Lamb is Neutral for Type A Non-secretors in Live Right 4 Your Type -- but in the BTD Encyclopedia, it's an Avoid. Which is correct?
The lectin lists on pages 348-49 conflict with the diet. Which is right?
For type O's in the Anti-inflammatory protocols, Yucca is listed with one value as a food and another as a medicine.
On page 103 of the Encyclopedia, Dr. D'Adamo recommends vitamin B6 (pyridoxine) in a dose of 20-30mg/kg for Type O's. Can you confirm if this is correct?