RT Journal
A1 STEININGER G, ROBERTS LJ
T1 BIophotometer test as index of nutritional status for vitamin a
JF Archives of Internal Medicine
JO Archives of Internal Medicine
YR 1939
FD December 1
VO 64
IS 6
SP 1170
OP 1186
DO 10.1001/archinte.1939.00190060039003
UL http://dx.doi.org/10.1001/archinte.1939.00190060039003
AB After the report by Jeans, Blanchard and Zentmire1 that the biophotometer may be used to measure a subject's nutritional status for vitamin A, work was begun in this laboratory, as in many others to test its usefulness for this purpose. The present article reports the results of over 2,000 biophotometer tests of 459 subjects—194 adults and 265 children during more than a year of experimentation. These tests have been made on subjects with both good and poor diets, with and without supplements on subjects kept for long periods on diets deficient in vitamin A and on subjects with very high levels of vitamin A intake. Furthermore, the reading for subjects on the depletion diets have been correlated with the amount of vitamin A found in the blood. The purpose of the testing has been to determine first the reliability of the test and then its validity as a measure