Book excerpt: Dr Joseph Chandy, a practicing doctor for almost 50 years, has written a fascinating and important book. Some 20 years after starting to practice, Dr Chandy came across a patient with vitamin B12 deficiency who presented with neurological symptoms, but without the characteristic changes in blood cells. In the subsequent 30 years, he dedicated himself in General Practice to identifying and treating patients who had insufficiency of B12. The book vividly described this very human story and the challenges he faced from the authorities who were reluctant to admit that he was making the correct diagnoses. The authorities behaved very badly in prioritising the 'rule book' over the clinical symptoms. The book shines throughout with Dr Chandy's devotion to the well-being of the patient and it should be read by all GPs, in training and those with experience. Medical scientists should also read the book since Dr Chandy ranges across several areas of medicine where much more research is needed. The book is very readable and full of helpful practical information. If the regulatory authorities read the book, it could lead to an improvement in an unsatisfactory aspect of the current practice of medicine.Note this version is printed in colour with colour diagrams and colour photographs. There is a much cheaper version printed in black and white. The charity www.b12d.org is selling both items at cost (cost of printing) so the price difference is entirely due to cost of printing. Please feel free to make a donation if you would like to.