XI. PATHOLOGY 503 



in which the responses obtained foUowing the injection of 80 7 of B12 were 

 suhoptimal. One of these patients was subsequently maintained in remis- 

 sion by the oral administration of 100 7 daily. 



7. Human Groavth Factor 



Vitamin B12 dietary supplementation was followed by promotion of 

 growth in children wlio.se growth rates were below standard, as measured 

 by Wetzel grid records. The effect of orally administered B12 was first 

 evaluated by Wetzel and associates^** in a small group of institutionalized 

 children. They reported substantial growth gains in 5 of 11 children with 

 retarded growth. A later study was conducted by Wetzel and others^** on 

 school children of a high-income suburban community. They found that, in 

 spite of their favorable economic situation and freedom from evidences of 

 malnutrition or chronic illness, one-third of the entire school population 

 were in relative growth failure. Vitamin B12 in daily oral doses of 10 7 was 

 administered to 36 of the 40 children with retarded growth rates. Four of 

 the group were untreated on their own volition. No changes in diet were 

 made in any of the children. Significant growth responses were obtained in 

 23 of the 36 treated children. The 4 untreated children showed, on suc- 

 cessive observations, aggravation of their growth failure. It was recorded 

 that retarded growth was accompanied by impaired academic achievement, 

 substandard physical performance, and increased fatiguability. Rapid im- 

 provement in all of these deficiencies was observed in children whose growth 

 failure was corrected by B12 supplementation. 



The observations of Wetzel and his coworkers are of great interest but 

 require confirmation and amplification by others before the conclusions 

 drawn from these studies can be fully accepted. The grid method of record- 

 ing physical development and fitness, devised by Wetzel, probably provides 

 the most precise measurement of growth rates which is available, but the 

 great number of variables which influence human growth render an ade- 

 quately controlled and objective study of this nature exceedingly difficult. 

 Further investigations should be carried out with particular reference to 

 dietary analyses of the subjects, random selection of B12 recipients and 

 controls, and provisions to avoid subjective bias on the part of those con- 

 ducting the tests as a possible determinant in the results. 



8. Neurologic Disorders 



Painful neuropathies associated with a miscellaneous group of conditions 

 including malnutrition, chronic alcoholism, diabetes, tal)es dorsalis, and 



63 N. C. Wetzel, W. C. Fargo, I. II. Smith, and J. Ilelikson, Science 110, G51 (1949). 

 ^0 N. C. Wetzel, H. H. Hopwood, M. E. Kuechle, and R. M. Grueninger, J. Clin. 

 Nutrition 1, 17 (1952). 



