1 The deBelle Laboratory for Biochemical Genetics, McGill University-Montreal, Childrens Hospital Research Institute, 2300 Tupper Street Montreal 108, Quebec, Canada
An excellent report on a form of Vitamin B12 dependency appears in this issue of the Journal. This Commentary, which has been written in response to the article, is the third on the subject of vitamin dependencies, the two previous discussing the Vitamin B6 dependencies (Pediatrics, 37:553, 1966) and Vitamin D dependency (Pediatrics, 45:361, 1970).
The term "vitamin dependency" has been used to describe certain types of genedependent nutritional disorders. In such conditions the nutritional intake of vitamin which is required to maintain a state of health is much greater than normal; patients evidently inherit these peculiar requirements in Mendelian fashion.