The effect of vitamin D on linear growth in infancy: II. The effect of intakes above 1,800 U.S.P. units daily

Abstract

Summary The rate of linear growth of nine infants given from 1,800 to 4,600 units of vitamin D daily has been compared with standard rates of growth, and with the growth of infants given the same dietary regimen but amounts of vitamin D varying from 135 to 340 units daily. The rates of growth with the very high vitamin D intake were similar to or less than those of infants given 135 units daily, and definitely lower than the growth rates of infants given 340 units of vitamin D daily. It is concluded that the effect of vitamin D on increasing linear growth reaches a maximum when the vitamin D intake is greater than 135 and less than 1,800 units, probably in the neighborhood of 340 to 600 units daily. Vitamin A in amounts exceeding those of the food (milk, vegetable, and fruit purees) apparently does not affect linear growth of infants. Factors affecting growth rates of individual infants are discussed. It is concluded that in order to determine the effect of the dietary regimen, growth should be studied well past 6 months of age, preferably during the greater part of infancy. Growth during the first 8 weeks of life may be affected by factors other than the dietary regimen of the infant.