Variations in liver concentrations of iron and vitamin A as a function of age in young American children dying of the sudden infant death syndrome as well as of other causes.

Concentrations of total iron and of vitamin A were determined in the livers of 33 Midwestern children, varying in age from 2 weeks to 9 years, who had died from the sudden infant death syndrome (SIDS) as well as from other causes. The median liver iron concentration was high (500 micrograms/g wet weight) in infants up to one month of age, fell rapidly during the ensuing months, and reached a plateau of 125 micrograms/g at approximately 1 year of age. No differences were noted between male and female children. The median liver vitamin A concentration was very low (4 micrograms/g) in infants less than or equal to 1 month of age, rapidly increased during the ensuing months, and reached a value of 100 micrograms/g by one year. The ratio of vitamin A to iron in the liver increased roughly 100-fold during the first few years of life. Infants dying of SIDS had stores of iron and vitamin A that fell in the normal range for age. Only one subject of the 33 studied showed an iron value less than 50 micrograms/g, and no infants more than 5 months of age showed a vitamin A value less than 20 micrograms/g. Thus, the storage of iron and vitamin A appear to be normal in the livers of infants suffering from SIDS.