In 1934 we1 described a photometer test for dark adaptation which we believed useful in detecting vitamin A deficiency. Subjects with impaired ability to adapt to the dark were found to attain normal standards of dark adaptation after a period of vitamin A ingestion. The study that was reported seemed to establish the validity of the dark adaptation test as a test of vitamin A deficiency. With the photometer test being used as the criterion, a survey was made among Iowa school children in an endeavor to determine the frequency of vitamin A deficiency. This presentation is for the purpose of recording the results of the survey.
The first phase of the study, i. e., the original testing, was conducted in 1934 from February to April inclusive. The total group examined comprised 404 children from 6 to 15 years of age selected at random from rural, village and urban
JEANS PC, ZENTMIRE Z. THE PREVALENCE OF VITAMIN A DEFICIENCY AMONG IOWA CHILDREN. JAMA. 1936;106(12):996-997. doi:10.1001/jama.1936.02770120028008