FACTORS ALTERING CONCENTRATION OF CAROTENOIDS 491 



italics) for plasma vitamin A in microgram per cent (including minimum 

 and maximum): 2 days, 23 (5-46); 1 month, 29 (11-72); 2 months, 36 

 (18-213); 3 months, 42 (21-120); 6 months, 47 (17-100); 9 months, 66 

 (23-125); 12 months, 50 (32-113); 15 to 18 months, 47 (19-143); 21 to 24 

 months, 44 (17-113); 27 to 36 months, U (27-102); 3.2 to 4.8 years, 39 

 (14-62); 5 to 6 years, 36 (18-96); 6.5 to 16 years, 35 (14-110). These 

 results are in line with those of Henley et al. m who found abnormally low 

 values for vitamin A in three- week-old premature infants; mean values 

 were only 20.4 microgram per cent (68 I.U.). These figures likewise agree 

 with those reported by Lewis and associates 864 for the fourth day of life, 

 after recovery from a precipitous drop to 11.1 microgram per cent (37 

 I.U.) within forty-eight hours after birth. It is suggested that both 

 failure of the liver to mobilize adequate quantities of vitamin A and the low 

 intake of the foodstuff are the responsible factors in the case of the new- 

 born. Lewis and co-workers 865 found that the serum vitamin A in some- 

 what older infants varied between 13.5 and 42.3 microgram per cent (45 

 and 141 I.U.) ; the results were practically identical for infants who had re- 

 ceived a daily supplement of 17,000 I.U. of vitamin A and for those who 

 had not been given the extra vitamin A. The values for the older chil- 

 dren were in the range reported by Robinson and co-workers 863 for children 

 six to sixteen years of age ; they reported averages of 30 to 36 microgram 

 per cent for the normal group and 31 to 35 microgram per cent for the 

 underprivileged group. As is the case with carotene, minimum values 

 of plasma vitamin A are noted in the newborn ; a maximum level is reached 

 at the age of nine months, after which a gradual decrease obtains. These 

 data lead one to conclude that, although the blood levels of carotene are 

 greatly suppressed and those of vitamin A are depressed to a lesser extent 

 in the newborn, the deficit is quickly overcome, and the levels soon reach 

 those considered normal for adults. 



(c) Plasma Carotene and Vitamin A in the Aged. The values for caro- 

 tene and vitamin A in the plasma of aged individuals would appear to be 

 somewhat lower than those reported for normal middle-aged adults. Thus, 

 Rafsky, Newman, and Jolliffe 866 reported the average plasma carotene as 80 

 microgram per cent (males, 74.7 and females, 85 microgram per cent), 

 while plasma vitamin A averaged 27.1 microgram per cent (males, 29.3 

 and females, 25 microgram per cent) in the case of fourteen males and fif- 



864 J. M. Lewis, O. Bodansky, and L. M. Shapiro, Am. J. Diseases Children, 66, 503-510 

 (1943). 



m J. M. Lewis, O. Bodansky, and C. Haig, Am. J. Diseases Children, 62, 1129-1148 

 (1941). 



868 H. A. Rafsky, B. Newman, and N. Jolliffe, Gastroenterology, 8, 612-615 (1947). 



