Vitamin intakes during rapid growth

Normal term gestation infants are expected to triple their birth weight by 12 months of age. Nutrient intakes during this critical period of life, therefore, are of paramount importance in ensuring optimal growth and development. Although primary vitamin deficiency diseases are rare in technically developed countries, a review of health problems in developing countries and a historical review of vitamin deficiency diseases in the U.S. indicate that the first year of life is a high-risk period for such deficiencies. The importance of preventing vitamin deficiencies in this age group is further emphasized by the fact that the Recommended Dietary Allowances (RDAs) include separate recommendations for two age groups during the first year of life, 0-6 months and 6-12 months. Since human milk has become a standard for the development of infant formulas, most studies have involved the age group from 0-6 months and have centered around determining the vitamin content of human milk and the correlation between intake and blood or urine measurements of vitamins. After six months of age. the source of dietary vitamins is quite varied. Moreover, since accurate estimation of vitamin intakes is time consuming and blood samples from normally growing children are difficult to obtain, few studies have been performed in this age group. It is not surprising, then, that the RDAs for infants between 6 and 12 months of age are based primarily on extrapolations of data from the first few months of life. The purpose of this chapter is to review, the history and scientific basis for recommended intakes, the health consequences of inadequate or excessive intakes and the adaptive response of infants to varied intakes of vitamins. Data concerning vitamin intakes, and, finally, the present RDAS for children 6-12 months of age also will be reviewed.